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Under U.S. O*NET-SOC 51-2031.00, assemble parts and components of engines and other machines into complete machines according to assembly drawings and process requirements, complete alignment, positioning, torque-tightening, test running, and inspection, and record parameters and defects.
This only verifies work-style preferences; it does not test hands-on ability, does not test qualifications, and does not constitute a hiring conclusion.
Use one paper-based exercise to verify: given a fictional assembly drawing and process summary, bill of materials, and parameter requirements, can you list the assembly sequence, alignment and torque points, inspection items, and record structure?
The core work of engine and other machine assemblers is to check assembly drawings and process requirements, draw and verify parts against the list, assemble components in sequence and complete alignment, positioning, and tightening, apply torque according to the process, test run and inspect key indicators, and record parameters and defects to complete quality traceability.
U.S. O*NET-SOC 51-2031.00 "Engine and Other Machine Assemblers": assemble parts and components of engines and other machines into complete machines according to assembly drawings and process requirements, completing alignment, positioning, torque-tightening, test running, and inspection.
Manufacturing urban non-private units 113,594 yuan/year (2025)
Industry proxy value: industry average scope, covering multiple occupations, cannot substitute for this occupation's wage.
Manufacturing urban private units 76,055 yuan/year (2025)
O*NET OnLine: Engine and Other Machine Assemblers (51-2031.00)｜https://www.onetonline.org/link/summary/51-2031.00; O*NET national wage percentile values (51-2031.00)｜https://www.onetonline.org/link/localwages/51-2031.00; BLS occupational projections (2024—2034)｜https://www.bls.gov/emp/tables/occupational-projections-and-characteristics.htm
38,500 U.S. dollars/year
| Entry direction | What you mainly do at the start | Employer requirements and observation basis | How to prove it without experience | How it differs from other directions |
|---|---|---|---|---|
| Component assembly entry | Verify parts and complete simple component assembly under supervision. | Evaluation from relevant coursework and practical training. | Demonstrate standards compliance with practical training process records. | Leans toward component assembly; requires attention to drawings and process steps. |
| Alignment and tightening entry | Assist in completing alignment, positioning, and torque tightening. | Measurement and tightening training. | Demonstrate the basis with torque and alignment records. | Leans toward alignment and tightening; requires attention to parameter documentation. |
| Test run and inspection entry |
Assemble parts and components of engines and other machines into complete machines according to assembly drawings and process requirements, complete alignment, positioning, torque-tightening, test running, and inspection, and record parameters and defects; excludes parts machining, in-service equipment repair, and structural fabrication.
Both do assembly, but team assemblers focus on production line workstation collaboration and takt; this occupation often involves complete machine assembly, alignment, and test running.
U.S. O*NET-SOC 51-2031.00 "Engine and Other Machine Assemblers," which is this occupation's own scope (not a broader group scope).
This occupation's own scope May 2025 median hourly wage 25.82 U.S. dollars and median annual wage 53,710 U.S. dollars; quintiles are 38,500 / 45,230 / 53,710 / 74,920 / 77,750 U.S. dollars.
More likely to suit: people who are willing to check item by item against drawings and processes, can do alignment, tightening, and parameter recording solidly, and proactively stop when parts are missing, parameters do not conform, or there are safety hazards.
This page does not constitute a practice, quality, or hiring conclusion; assembly quality determination and release may only be made by personnel with the responsibility and authorization according to applicable processes and enterprise rules.
First judge whether you can check rigorously against drawings and processes, get alignment and tightening right, write parameters and defects clearly, and are willing to stop when parts are missing, parameters do not conform, or there are safety hazards; then judge whether you can maintain stable quality under a high-intensity takt; verify with the paper exercise and seven-day experience on this page, not just by the single point of "hands-on assembly."
Work context｜Engine and other machine assemblers work mainly in manufacturing workshops and assembly sites, completing a work loop around drawing verification, material verification, assembly alignment, tightening torque, test run and inspection, and record traceability. Work location｜Manufacturing workshops, assembly lines, and test stations. Working conditions｜Requires prolonged standing, carrying, and tool use, and may involve lifting, machinery, and energy isolation. Main objects｜Parts and components, tooling and measuring instruments, complete machines and test equipment. Collaborative relationships｜Requires coordination with process, materials, inspection, and upstream and downstream workstations. Tools and materials｜Hand and power tools, torque tools and measuring instruments, assembly drawings and process documents. Institutional basis｜Local safety protocols, enterprise assembly processes, and quality rules. Record requirements｜Parameter, inspection, and defect records must be documented according to institutional rules. Safety boundary｜Work must be performed according to safety protocols; assembly quality determination and release may only be made by personnel with the responsibility and authorization.
Includes parts, components, and tooling
The wages checked are for this occupation's own scope: May 2025 median hourly wage 25.82 U.S. dollars and median annual wage 53,710 U.S. dollars; percentiles 38,500 / 45,230 / 53,710 / 74,920 / 77,750 U.S. dollars.
Verify assembly drawings and processes → draw and verify parts → assemble components and align → tighten to torque → test run and inspect → record parameters and trace
Job Zone 1-2 (little to some preparation): typically requires a high school diploma or equivalent plus on-the-job training; the education survey is high school 64% / postsecondary certificate 13% / less than high school 11%; actual work must follow applicable processes and the enterprise's inspection requirements.
Complete machine assembly as the main deliverable
In China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
Confirm the drawing version → verify the bill of materials → assemble in sequence → review alignment and tightening → confirm by test run → retain records and defect information
51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality.
Deliverable: a conforming complete machine and assembly inspection records
A complete loop means the full chain from verifying drawings and processes, verifying materials and parts, assembly and alignment, test running and inspection, to records and traceability; if any step lacks version verification, parameter records, or inspection items, neither assembly quality nor traceability holds.
Any change must be re-confirmed
Drawing verification: drawing and process versions confirmed
Missing and wrong parts must be registered
Material verification: part models and quantities verified
Occupational boundary: this page is written for U.S. O*NET 51-2031.00 "Engine and Other Machine Assemblers," referring to positions that assemble parts and components of engines and other machines into complete machines according to assembly drawings and process requirements, complete alignment, positioning, torque-tightening, test running, and inspection, and record parameters and defects; it excludes parts machining, in-service equipment repair, and structural fabrication. It differs from team assemblers (production line workstation collaboration), structural metal fabricators and fitters (structural fabrication and installation), machinists (parts machining), industrial machinery mechanics (in-service repair), welding operators (welded joints), and electrical and electronic equipment assemblers (electrical component assembly) in deliverables and basis.
Alignment and tightening must be correct
Assembly alignment: assemble in sequence and complete alignment
Key parameters must be documented
Tightening torque: apply torque according to the process and record it
Inspection items must not be omitted
Test run and inspection: test run and inspect according to protocol
Do not substitute organized records for the original records
Record traceability: complete key records and review
Keep the basis and the responsible person
Anomaly reporting: explain missing parts, defects, or hazards according to institutional rules
This occupation focuses on assembly, alignment, and test running of engines and complete machines; team assemblers face production line workstation collaboration; structural metal fabricators and fitters face structural fabrication and installation; machinists face parts machining; industrial machinery mechanics face in-service equipment repair; welding operators face welded joints; electrical and electronic assemblers face electrical component assembly.
A conforming complete machine and inspection records
Workshop and assembly site
High school diploma and on-the-job training
U.S. figures are this occupation's own scope statistics
No precise occupation-level wage mapping established
This page does not replace processes or institutional rules
Adjacent directions differ in deliverables (production line finished products, structural members, machined parts, in-service equipment repair, welded joints, electrical and electronic components) and basis (assembly drawings, machining drawings, welding processes, electrical schematics); before choosing, first verify the target position's actual tasks, local standards, and position training requirements.
The comparison is based on the official occupational profiles of O*NET 51-2031.00 and related occupations (tasks, tools, preparation level, and work environment); it does not represent individual transferability or a wage conclusion.
The following occupations are all on the manufacturing, assembly, and equipment maintenance chain, but they differ in deliverables, basis, and way of working; use them to check direction, not as substitutes for one another.
Mainly fixed workstations and takt collaboration; this occupation often involves complete machine assembly, alignment, and test running.
Choose that occupation for a preference for production line collaboration; choose this occupation for a preference for complete machine assembly and commissioning.
Assemble components or products in collaboration at production line workstations according to takt.
Team Assemblers
Mainly structural member fabrication and installation; this occupation focuses on assembly and inspection of complete machines.
Choose that occupation for a preference for structural fabrication and installation; choose this occupation for a preference for complete machine assembly.
Fabricate and install structural metal members and frames on site.
Structural Metal Fabricators and Fitters
Mainly parts machining; this occupation assembles parts into complete machines according to drawings and inspects them.
Choose that occupation for a preference for parts machining; choose this occupation for a preference for complete machine assembly and commissioning.
Machine precision parts on machine tools and ensure dimensional tolerances.
Machinists
Faces repair of in-service equipment; this occupation faces new-build manufacturing and test running.
Choose that occupation for a preference for repair diagnosis; choose this occupation for a preference for assembly and test running.
Maintain, diagnose, and repair in-service mechanical equipment.
Industrial Machinery Mechanics
Mainly welding and joining work; this occupation is mainly mechanical component assembly, alignment, and tightening.
Choose that occupation for a preference for welding work; choose this occupation for a preference for mechanical assembly and inspection.
Operate welding and brazing equipment to complete joining work.
Welding, Soldering, and Brazing Machine Setters, Operators, and Tenders
Mainly electrical and electronic component assembly; this occupation faces engine and complete machine assembly.
Choose that occupation for a preference for electrical and electronic assembly; choose this occupation for a preference for mechanical complete machine assembly.
Assemble electrical and electronic equipment and wiring harnesses.
Electrical and Electronic Equipment Assemblers
Compare in the order of "first whether the deliverable is a complete machine, structural member, machined part, repair result, or component assembly, then the basis and way of working."
Students currently studying
First complete mechanical drafting, mechanical fundamentals, and practical training courses, and accumulate hands-on experience through assembly practice.
In-service personnel
Hand document verification and record organization to tools, while keeping the judgment right over alignment, tightening, and conformance determination yourself, with documentation.
Career changers or job seekers
First verify the target region's education and training requirements for assembly positions, and prove your ability with reviewable sample assembly records.
Institutions and preceptors
Define the scope of tool use, process data permissions, and quality responsibility, and ensure that assembly quality and conformance determination are handled by personnel with the responsibility.
AI can assist in reading assembly drawings and process records, verifying bills of materials and torque parameters, and generating assembly step drafts and quality checklists, but it cannot replace parts verification, judgment that alignment and tightening are correct, test running and safety confirmation, or responsibility for assembly quality and conformance determination.
O*NET occupational profile
This occupation's tasks and preparation level.
Growth and openings are not AI-causal; this is not a wage item.
BLS wage release
Not a regulation, exposure study, or operating standard.
ILO information entry point
Not a specific empirical paper.
O*NET occupational profile
Not an employer survey or interest validity validation.
BLS projections
Not an AI risk framework.
BLS wage release
Not occupational tasks or operating standards.
The conditions and responsibilities differ across document verification, assembly work, parameter tightening, and inspection, and so does AI's role.
Editorial trial: drawing parameter and material verification drafts, effect not verified.
Version and incoming-material applicability are still verified by assembly personnel.
Editorial trial: operation reminders and record prompts, effect not verified.
Alignment, correct tightening, and torque authenticity remain the responsibility of assembly personnel.
Editorial trial: inspection checklists and record drafts, effect not verified.
Conformance determination and record signing remain the responsibility of assembly personnel.
Task-informed editorial trial; capability, actual adoption, measured benefit, and job causality are evidenced separately; this round obtained no precise occupation-level AI adoption or effect study.
Occupational task profiles are not tool effect trials.
O*NET this occupation
Tasks and editorial suggestions
Assembly-to-drawing, parts verification, measurement, and inspection tasks inform document and record draft trials, which cannot prove actual speed gains or AI adoption.
Does not claim to be an adoption-rate survey.
Occupational information and editorial judgment
Adoption-condition editorial analysis
This round obtained no precise occupation-level institutional adoption survey; before trialing, verify the system, data sources, permissions, and human review.
Overall projections are not AI-causal; the wage and employment occupational scope is retained.
BLS2025—2035
Overall employment projections
51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality.
Jurisdiction, scope of application of the standard, and institutional role are verified separately; no AI effect is predicted.
Current Work Safety Law
China position boundary
In China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
An information entry point does not claim to be an empirical paper.
ILO information entry point
International information entry point
Insufficient evidence: no measured AI or job-causality study for this occupation was obtained.
Technical capability: the tasks a tool can complete under controlled conditions, such as document organization, parameter prompts, and quality checklist drafts; not equivalent to being usable for assembly quality determination or safety confirmation.
Adoption conditions: whether an enterprise is actually using it depends on whether process data are digitized, whether equipment can be instrumented, and on quality and safety requirements.
Job outcomes: refer to changes in employment and task structure, which require industry-level statistical support; technical capability and adoption do not directly imply job outcomes.
You cannot infer this. Tools can assist with document verification and record organization, but alignment, tightening, test running, and conformance determination remain the responsibility of assembly personnel with that duty.
Occupational tasks and editorial suggestions, not adoption measurement
No. Quality is constrained by processes, parameters, and inspection conditions, and tool output can only serve as a supporting checklist.
Occupational tasks and editorial suggestions, not adoption measurement
Editorial suggestion: trial version, material, and missing-item checks with fictional drawing summaries and records; parameters follow the approved process, no speed gains are guaranteed, and drafts must not automatically control real equipment.
Occupational tasks and editorial suggestions, not adoption measurement
51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality. Cannot imply individual hiring or AI replacement.
Occupational tasks and editorial suggestions, not adoption measurement
The focus is on assembly processes and torque requirements, mechanical drafting and measurement, test run protocols, and quality records and safety protocols.
Occupational tasks and editorial suggestions, not adoption measurement
Large. The assembly processes and takt differ across engine manufacturing, heavy machinery, and general equipment, so direction choices must be verified against the target position.
Occupational tasks and editorial suggestions, not adoption measurement
It can only serve as a direction reference. Employment and wages are statistical scopes, and actual requirements depend on the target region's standards and job postings.
Occupational tasks and editorial suggestions, not adoption measurement
As AI enters the assembly process, the chain of responsibility remains with people; preserve traceability by following the steps below.
Verify drawings and processes: read the assembly drawing and process requirements and verify the version, recording the basis and open items.
Verify materials and parts: draw and verify part models, quantities, and incoming-material status against the list.
Assembly and alignment: assemble components in sequence and complete alignment, positioning, and tightening.
Test run and inspection: test run and inspect key indicators according to protocol, recording parameters and defects.
Records and traceability: complete key records and review, retaining original data and basis.
May cause rework and quality incidents.
Verify drawing and process versions before assembly, and re-confirm when they change.
May cause personal injury.
Use lifting and protective equipment according to protocol and confirm energy isolation.
May cause equipment failure or leakage.
Apply torque according to the process and record key parameters.
May result in delivery with defects.
Test run according to protocol and verify inspection items one by one.
May affect quality traceability and responsibility allocation.
Document according to institutional rules and retain the original records.
Drawing version and process applicability are verified by assembly personnel.
Read the assembly drawing and process requirements and verify the version
Drawing and process verification
Can assist: organize key dimensions and torque parameters.
Part applicability and incoming-material status are confirmed by assembly personnel.
Draw and verify part models and quantities against the list
Material and part verification
Can assist: check missing and wrong parts.
Assembly sequence, alignment, and correct tightening are confirmed on site by assembly personnel.
Assemble components in sequence and complete alignment and positioning
Component assembly and alignment
No automatic authorization
Tightening quality and record authenticity are the responsibility of assembly personnel.
Apply torque according to the process and record key parameters
Tightening and torque control
Can assist: prompt torque values and missing record items.
Test run conclusions and conformance determination are the responsibility of assembly personnel.
Test run according to protocol and inspect key indicators
Test run and inspection
Can assist: generate inspection checklists and record drafts.
Defect determination and disposition decisions are the responsibility of personnel with that duty.
Record defects, rework, and anomalies and report according to the process
Issue handling and traceability
Can assist: organize defect classification and traceability information.
Stop and explain immediately upon finding missing parts, non-conforming parameters, or a safety hazard.
Identify out-of-scope, missing-part, or safety-hazard situations
Boundaries and safety
Adoption conditions: reliable data, compliant permissions and safety.
Technical capability, actual adoption, and job outcomes are judged separately and do not substitute for one another.
Private-unit industry proxy: different from the non-private scope of the same industry and must not be mixed.
Assembly position classifications in mainland China are not a one-to-one match with this U.S. occupation's scope
Position scope: responsibility boundaries must be verified by industry and region.
Monthly salary, annual salary, performance pay, and overtime pay scopes must not be mixed
Pay unit: if a posting includes performance pay or overtime pay, it cannot be converted into a stable monthly salary.
Verify against the source's publication period; do not merge different years
Statistical period: industry averages from different years cannot be compared directly.
The industry scope includes multiple occupations
Industry coverage: an industry average cannot represent this occupation's wage.
City and regional differences are significant; verify by place of work
Regional differences: a national average cannot represent a specific city.
A recruitment quote is a single-employer sample and does not constitute an occupational median
Sample boundary: do not substitute a single quote for occupational wages.
Insufficient evidence: no precise occupation-level AI adoption, measured benefit, or wage-job causality evidence was obtained; tool trials are editorial suggestions.
Scope note: the industry average wage covers multiple occupations and cannot substitute for this occupation's wage distribution.
A mechanical, electromechanical, or related educational background
In China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
Assembly processes and measurement
On-the-job training centers on assembly processes, torque requirements, mechanical drafting and measurement, and safety protocols.
Qualifications and authorization
Position qualifications and inspection authorization
The scope of assembly and inspection is verified according to local protocols and enterprise rules.
Insufficient evidence: no national single-occupation distribution was obtained.
Machinery and equipment manufacturing
Positions requiring component and complete machine assembly and inspection.
Engine and power equipment manufacturing
Positions requiring engine assembly, alignment, and test running.
Heavy and general equipment manufacturing
Positions requiring heavy machinery assembly and commissioning.
National Bureau of Statistics average wage of urban units (manufacturing)｜https://www.stats.gov.cn/sj/zxfb/
Insufficient evidence: this round obtained no precise occupation-level national wage percentiles for China; the industry average serves only as background, and a failed retrieval does not justify asserting that nothing has been published nationally.
Insufficient evidence: no precise occupation-level percentiles were obtained this round.
If you see a recruitment figure, first verify whether it is a monthly salary, annual salary, performance pay, overtime pay, or includes another scope.
National Bureau of Statistics 2025 urban unit wages｜https://www.stats.gov.cn/sj/zxfb/202605/t20260515_1963707.html
Do not substitute an industry average wage or a single recruitment quote for this occupation's wage.
National single occupation
Insufficient evidence: no national single-occupation scope was obtained
Industry average wage (not substitutable)
2025 manufacturing non-private 113,594 yuan and private 76,055 yuan pre-tax annual average wage; industry background, not the single-occupation wage of engine assembly or an individual's stable monthly salary.
Recruitment quotes (not substitutable)
Insufficient evidence: do not substitute a single recruitment quote for occupational wages.
Scope note: the classification of assembly positions in mainland China is not a one-to-one match with this U.S. occupation's scope.
Notes on the U.S. O*NET wages for this occupation and the BLS projection scope｜https://www.bls.gov/oes/
51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality.
53,710 U.S. dollars/year (median hourly wage 25.82 U.S. dollars, May 2025 OEWS)
Pay · 10th percentile｜38,500 U.S. dollars/year; national 10th percentile｜not an entry-level starting wage.
45,230 U.S. dollars/year
Pay · 25th percentile｜45,230 U.S. dollars/year; national 25th percentile｜from the same wage statistical scope.
53,710 U.S. dollars/year
Pay · median｜53,710 U.S. dollars/year; median (median hourly wage 25.82 U.S. dollars, May 2025)｜half of workers earn below and half above this value.
74,920 U.S. dollars/year
Pay · 75th percentile｜74,920 U.S. dollars/year; national 75th percentile｜from the same wage statistical scope.
77,750 U.S. dollars/year
Pay · 90th percentile｜77,750 U.S. dollars/year; national 90th percentile｜does not represent continuous paid hours or total income.
33,500 people
2025—2035 employment · base-year figure｜33,500 people; 2025 single occupation｜overall projections are not AI-causal and do not guarantee individual hiring.
2025—2035 employment · projected growth｜-17.0%; 2025—2035 single occupation｜overall projections are not AI-causal and do not guarantee individual hiring.
2,100 per year
2025—2035 employment · projected openings｜2,100 per year; includes replacements, not net new additions｜overall projections are not AI-causal and do not guarantee individual hiring.
The above are U.S. statistics for this occupation's own scope; they do not represent wage levels or job demand in mainland China; when using them, the occupation, region, period, and unit scope must be retained.
2025 U.S. national median for this occupation 53,710 U.S. dollars/year and 25.82 U.S. dollars/hour; 51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality.
The median hourly wage of 25.82 U.S. dollars and median annual wage of 53,710 U.S. dollars are medians in this occupation's own scope statistics; individual income depends on region, industry, skills, and shift.
51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality.
Employment and growth
Training and position qualifications affect the assembly and inspection duties one can take on, but release authority is not inferred directly from the occupation title.
Qualifications and authorization
-17.0%（2025—2035）
Machinery manufacturing
Insufficient evidence: this round obtained no source table of wage for this occupation × this industry.
An industry distribution or a broader-occupation wage cannot substitute for this occupation × industry median.
Engine and power equipment manufacturing
Insufficient evidence: this round obtained no source table of wage for this occupation × this industry.
An industry distribution or a broader-occupation wage cannot substitute for this occupation × industry median.
Heavy and general equipment assembly
Insufficient evidence: this round obtained no source table of wage for this occupation × this industry.
An industry distribution or a broader-occupation wage cannot substitute for this occupation × industry median.
Wage May 2025, projections 2025—2035; occupational scopes for the statistics are retained separately.
No. The statistical median is not an individual starting wage, and this page's wage occupational scope must be retained.
An individual's annual salary requires verifying actual paid hours, shifts, and contract; do not guarantee individual contractual income from the hourly median.
2025 U.S. national 51-2031 percentile values 38500 / 45230 / 53710 / 74920 / 77750, single occupation; employment comes from the BLS2025—2035 table 1.2, not AI-causal.
Region, employer, experience, specific duties, and qualifications; Chinese income is not directly extrapolated to the U.S. distribution.
53,710 U.S. dollars/year (median hourly wage 25.82 U.S. dollars, May 2025 OEWS)
Low end: 10th percentile 38,500 U.S. dollars/year, at the low end of the distribution, not an entry-level starting wage.
Median: 53,710 U.S. dollars/year (median hourly wage 25.82 U.S. dollars, May 2025 OEWS); half of workers earn below and half above this value.
High end: 90th percentile 77,750 U.S. dollars/year, usually related to region, industry, and skills.
Basis and documentation: verify with observable behavior, for example whether work is checked against drawings and processes, whether torque and inspection parameters are recorded, and whether the person proactively stops when parts are missing or there is a safety hazard.
Not a personality diagnosis, ability score, or hiring conclusion.
Process awareness: verify with observable behavior, for example whether work is checked against drawings and processes, whether torque and inspection parameters are recorded, and whether the person proactively stops when parts are missing or there is a safety hazard.
Work sample
Not a personality diagnosis, ability score, or hiring conclusion.
The interest code RC is used only to describe work activity preferences and is not an ability, hiring, or personality conclusion.
Operational rigor: verify with observable behavior, for example whether work is checked against drawings and processes, whether torque and inspection parameters are recorded, and whether the person proactively stops when parts are missing or there is a safety hazard.
Realistic (R) — oriented to hands-on assembly, alignment, and test running; Conventional (C) — oriented to drawings, torque, and quality record standards.
Work sample
Not a personality diagnosis, ability score, or hiring conclusion.
Communication and collaboration: verify with observable behavior, for example whether work is checked against drawings and processes, whether torque and inspection parameters are recorded, and whether the person proactively stops when parts are missing or there is a safety hazard.
Work sample
Not a personality diagnosis, ability score, or hiring conclusion.
Learning motivation: verify with observable behavior, for example whether work is checked against drawings and processes, whether torque and inspection parameters are recorded, and whether the person proactively stops when parts are missing or there is a safety hazard.
Not a personality diagnosis, ability score, or hiring conclusion.
Work safety: verify with observable behavior, for example whether work is checked against drawings and processes, whether torque and inspection parameters are recorded, and whether the person proactively stops when parts are missing or there is a safety hazard.
Work sample
Not a personality diagnosis, ability score, or hiring conclusion.
The following is a work-style observation checklist, not a personality diagnosis, and does not constitute a hiring or ability conclusion.
The key question is not "whether you are willing to work with your hands," but whether you can check item by item against drawings and processes, get alignment, tightening, and parameter recording right, and stop and explain immediately when parts are missing, parameters do not conform, or there is a safety hazard.
Team assembly
Process records and collaboration can be compared.
Add production line workstation takt, handover, and target assembly objects.
Mechanical parts machining
Drawing and dimension verification can be compared.
Add machine tool operation, cutting processes, and machining safety.
Industrial machinery repair
Equipment structure and measurement can be compared.
Add in-service fault diagnosis, overhaul, and energy isolation.
Electromechanical equipment assembly
Assembly and inspection can be compared.
Add electrical connections, electromechanical interfaces, and the corresponding safety requirements.
In-occupation specialization within machine assembly
Alignment, parameter, and inspection preferences are observable.
Verify approved processes, position training, and enterprise quality release authority.
Tool and die making
Precision and drawing verification can be compared.
Add tool and die design understanding, precision machining, materials, and heat treatment.
Suits people who are willing to check item by item against drawings and processes, get alignment, tightening, and parameter recording right, and value safety; it does not suit people who skip steps by feel, ignore missing parts, or deliver with defects.
In the U.S., typically a high school diploma or equivalent plus on-the-job training is required, and some positions require a postsecondary certificate; O*NET 51-2031.00 is Job Zone 1-2. Mainland China often requires a mechanical, electromechanical, or related educational background plus assembly experience.
In China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
Prove it through assembly and inspection records from practical training, course design, and workshop internships, and write out the basis and process steps clearly.
Document verification and record organization tasks can be assisted by tools, but alignment, tightening, test running, and conformance determination remain the responsibility of assembly personnel with that duty.
The 2025 U.S. median for this occupation is 53,710 U.S. dollars, not a starting wage; precise percentiles for China were not obtained, and the manufacturing industry average serves only as background.
Work in workshops on assembly and test running, possibly standing for long periods, carrying, and using tools, requiring protective measures according to protocol and attention to lifting and machinery safety.
Mechanical drafting and measurement, assembly processes and torque requirements, alignment and commissioning, test running and inspection, quality records and traceability, and safe working and collaboration skills.
Use one paper-based exercise to complete the full loop: read a fictional assembly drawing and process, list the assembly sequence and torque points, and write out the inspection items and record structure.
This page is a career exploration reference and does not constitute a practice, quality, or hiring basis; actual requirements are subject to local protocols, enterprise rules, and job postings.
Willing to write out the basis, parameters, and limits of each assembly and inspection step so others can review them.
When parts are missing, parameters do not conform, or conditions are not met, explain and stop first rather than continuing by feel.
Stays sensitive to work safety, quality requirements, and process confidentiality, preferring to confirm once more rather than skip a step.
U.S. tasks for this occupation and the corresponding wage and employment statistics.
This occupation's tasks and activities are not an operating authorization.
Overall employment projections are not a regulation.
A wage release is not China training.
U.S. training retrieval is not safety law.
A U.S. certification entry point is not adjacent-occupation tasks.
U.S. tasks, education, and work context, not a personality validity validation.
China's personal information law is not a wage method.
This page does not replace local protocols, enterprise rules, or safety regulations; assembly quality determination and release may only be made by personnel with the responsibility and authorization.
The main risks center on drawing and process versions, lifting and machinery safety, tightening and parameter defects, omissions in test running and inspection, and record and traceability defects; most can be reduced through version verification, protocols, and review, but they cannot be completely eliminated.
O*NET tasks and work context support risk exploration; risk consequences and responses are editorial summaries, not accident probabilities, operating protocols, or measured control effects.
Frontline assembly positions
May cause rework and quality incidents.
Verify drawing and process versions before assembly, and re-confirm when they change.
Using an outdated drawing or process causes assembly deviation.
Assembly and handling positions
May cause personal injury.
Use lifting and protective equipment according to protocol and confirm energy isolation.
Inadequate protection against lifting, handling, or machinery injury.
Assembly and tightening positions
May cause equipment failure or leakage.
Apply torque according to the process and record key parameters.
Insufficient or excessive torque, or a wrong tightening sequence.
Test run and inspection positions
May result in delivery with defects.
Test run according to protocol and verify inspection items one by one.
Test run conditions do not conform or inspection items are omitted.
May affect quality traceability and responsibility allocation.
Document according to institutional rules and retain the original records.
Missing parts, rework, or incomplete parameter records.
Material and assembly positions
May cause assembly deviation or early failure.
Verify incoming material against inspection requirements and record non-conforming information.
Incoming material dimensions or materials do not meet assembly requirements.
A U.S. certification entry point is not a regulation or operating protocol.
This occupation's scope is not an accident rate.
This occupation's task context is not an operating authorization.
China personal information protection; U.S. jurisdictions are verified separately, not a wage.
An industry distribution is not an occupational safety protocol.
| Assist with test running and record key inspection items. |
| Test run and inspection training. |
| Demonstrate rigor with inspection record sheets. |
| Leans toward inspection; requires attention to complete items. |
| Material and site support entry | Assist with material verification, tooling preparation, and document archiving. | Materials and process fundamentals. | Demonstrate orderliness with material verification sheets and archiving checklists. | Leans toward materials and support; requires attention to registering missing parts. |
| Quality support entry | Assist in checking whether the assembly process and records conform to the process requirements. | Quality and process training. | Demonstrate rigor with quality checklists. | Leans toward quality; requires attention to process applicability. |
Employer requirements: education and major
Verify high school education or above and mechanical or electromechanical major and training requirements, and record the posting date and whether it is still open.
Distinguish "aware of" from "proficient"; do not substitute a course name for actual assembly ability.
Employer requirements: qualifications and compliance checks
Verify explicit requirements such as position training, special operations (such as lifting), and physical examinations.
Record the validity of qualifications and training; cross-region or cross-enterprise must be re-verified.
Employer requirements: occupational traits and physical demands
Verify O*NET-related occupational traits (attention to detail, dependability, hands-on ability) and physical demands such as carrying and standing.
Verify with observable behavior and workshop performance; do not draw conclusions using personality labels.
Employer requirements: assembly and measuring instrument use
Verify requirements for using hand and power tools, torque tools, and measuring instruments.
Distinguish "can get started" from "already proficient," and verify the items subject to assessment.
Material one: fictional assembly drawing and process summary
Provide the assembly scope, key dimensions, and process requirements as input for this exercise.
Flag the check items, missing items, and version differences.
List the conditions and reasons that may affect assembly quality.
State that the exercise uses fictional materials and does not represent any real product or enterprise.
Reviewable output: assembly sequence, alignment and torque points, record structure.
Explain the process and safety boundaries; missing parts, non-conforming parameters, or safety hazards require stopping and explaining.
Material two: torque and inspection requirements excerpt (fictional)
Provide key points of torque parameters and inspection items.
Exercise output: write out the source of basis and scope of application for this assembly and inspection.
Material three: material and parameter table (fictional)
Provide a parts list and key parameters, including one missing part and one parameter contradiction.
Exercise output: mark the missing part and contradictory items, and write out the requirements for verification and obtaining the missing parts.
Exercise output: organize key parameters and inspection items according to the process.
Material four: deliverables and boundary description
List the reference deliverables and the scope that must not be overstepped (no real assembly, quality determination, or safety operation involved).
Work one: job requirement comparison table
List the education, major, training, and experience requirements of the target posting item by item in a comparison table.
Mark the items already met, to be completed, and needing verification.
Work two: assembly process and parameter record
Write out the process steps and the alignment and torque parameter records for one fictional assembly.
Show that you can find missing parts and parameter problems and proactively explain at the boundary.
Work three: test run and inspection summary
Write out the test run conditions, inspection items, and conclusion structure according to protocol.
Show awareness of inspection record traceability and standards compliance.
Work four: measuring instrument and tooling description
Compile a measuring instrument and tooling user guide and explain the applicable conditions.
Show attention to measurement and process basis.
| Scenario | What to check | How to observe | What cannot be inferred from it |
|---|---|---|---|
| Interview | Whether the person can explain the assembly process, alignment, and torque requirements. | Check whether the process steps, parameters, and record requirements are written clearly. | When conditions do not conform, the enterprise and the position make the determination, not the individual. |
| Hands-on assessment | Whether the person can complete simple component assembly and inspection according to drawings. | Check process compliance, correct alignment and tightening, and complete records. | If not passed, must not take on independent assembly and release. |
| Trial and preceptorship period | Complete assembly, test running, and records under supervision and with documentation. | Check process compliance, parameter records, and collaboration performance. | Stop and explain immediately on missing parts, non-conforming parameters, or a safety hazard. |
| Independent performance period | Independently complete assembly within the authorized scope and cooperate with inspection. | Check quality records, rework handling, and safety compliance. | Any out-of-scope or violating situation is handled according to enterprise rules. |
Day 1: read one assembly drawing
Copy out the key dimensions and process points and write out the applicable conditions and uncertainties.
Day 2: do one material verification
Use a fictional list to verify part models and quantities, marking missing and wrong parts.
Day 3: write one assembly process
Write out the component assembly and alignment steps in sequence and mark the key control points.
Day 4: do one torque record
Write out the torque values and tightening sequence according to the process and state the recording requirements.
Day 5: do one inspection checklist
Write out the inspection items and conformance criteria for one test run.
Day 6: make two variants
Change one missing-part situation and one parameter change respectively, and write out the impact and adjustments clearly.
Day 7: review the stop conditions
Summarize the situations in which you must stop and explain, forming a one-page review record.
| Qualification/preparation item | Mainly suits whom | Practical role in job seeking | Whether it is a general entry threshold | Enrollment/handling conditions | Investment considerations | Important limits |
|---|---|---|---|---|---|---|
| High school diploma or equivalent | Most entry-level job candidates | Yes: about 64% of respondents in the O*NET survey said high school is required | Yes: typical U.S. entry point | Apply according to enterprise hiring requirements | Investment in basic education and on-the-job training | A diploma does not equal release qualification |
| Postsecondary certificate (mechanical or electromechanical direction) | Those planning to enter quickly | Depends on the position: about 13% of respondents in the O*NET survey said a postsecondary certificate is required | No: not a general threshold | Apply according to the requirements of the school or training provider | Several months to one year of training investment | A certificate does not equal automatic authorization by any enterprise |
| Less than high school (made up through on-the-job training) | Some candidates entering through experience | Depends on the position: about 11% of respondents in the O*NET survey said less than high school | No: not a general threshold | Apply according to enterprise hiring requirements | Mainly accumulated through on-the-job training | Entry requirements are verified by enterprise and position |
| On-the-job training and position experience | Positions that carry assembly and inspection duties | Yes: usually required | No: verify according to enterprise requirements | Attend training and preceptorship according to enterprise rules | Investment in training and position accumulation | Cannot be inferred from education level or occupation title |
| Special operation qualifications such as lifting | Positions that must operate lifting equipment | Depends on the position: according to enterprise requirements | No: it is a special operation requirement | Train and obtain the certificate according to local rules | Training and re-examination investment | Valid only within its applicable region and scope of work |
| Mainland China position qualification | Machinery and equipment assembly positions | Depends on jurisdiction: usually required | No: verify according to local rules | Take the examination and physical check according to the job posting | Investment in exam preparation and hiring procedures | Valid only within its applicable region and position |
The education, major, training, and experience requirements in a job posting must be read item by item; one item being relaxed does not mean other conditions can be substituted.
The works and seven-day experience suggested on this page are only for career exploration and do not constitute a practice, quality, or hiring conclusion.
Assembly quality determination and release may only be made by personnel with the responsibility and authorization according to applicable processes and enterprise rules.
The exercises on this page use fictional materials and do not represent any real product, enterprise, or assembly result.
Entering this occupation is not just about choosing a major: first verify the target region's position definition, major and training requirements, and assembly and inspection duties, and record the posting date and whether it is still open.
Recruitment samples are only used to illustrate the dimensions to verify and cannot substitute for local protocols and enterprise rules.
The three tracks and four stages are an editorial capability path, not a uniform grade certificate; practical training and paper exploration do not automatically confer inspection release, special operation, or equipment operating authority.
Read the assembly drawing and process requirements and verify the version, recording the basis and open items.
Verify drawings and processes
Assemble components in sequence and complete alignment, positioning, and tightening.
Assembly and alignment
Test run and inspect key indicators according to protocol, recording parameters and defects.
Test run and inspection
Complete key records and review, retaining original data and basis.
Records and review
U.S. JobZone1—2, respondent education 64% high school / 13% postsecondary certificate / 11% less than high school; the survey is not a uniform legal requirement; China: in China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
In China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
Assembly qualifications, inspection authorization, and scope of work are verified by locality, institution, and employer; requirements differ across regions and enterprises.
U.S. JobZone1—2, respondent education 64% high school / 13% postsecondary certificate / 11% less than high school; the survey is not a uniform legal requirement; China: in China, ordinary assembly position training, enterprise quality release, and legally licensed special operations are verified separately; the Work Safety Law requires safety education and training, and special operations require the corresponding qualification; an assembler title must not be treated as a special operation across the board, nor does completing an assembly course automatically authorize electrical or welding work.
A wage release is not training regulation.
A U.S. certification directory is not occupational tasks.
A U.S. occupational profile is not a China training entry point.
Occupational task information is not a wage method.
Verify by locality and institution.
Independently take on component assembly.
Training records and process records.
Participate in parts verification and simple component assembly under supervision.
Assembly assistant
Verify by locality and institution.
Take on complete machine assembly or precepting.
Assembly records and inspection records.
Independently complete component assembly, alignment, and tightening and record parameters.
Verify by locality and institution.
Take on the section leader role.
Complete machine records and quality records.
Take on complex complete machine assembly, commissioning, and issue handling.
Senior assembler
Verify by locality and institution.
Develop toward production management.
Production and quality records.
Coordinate section progress, quality, and staffing.
Section leader
Verify by locality and institution.
Take on engine commissioning.
Specialized records and test data.
Take on engine complete machine assembly, alignment, and test running.
Engine assembly specialization
Verify by locality and institution.
Take on precision problem resolution.
Measurement records and adjustment records.
Take on high-precision alignment and geometric accuracy adjustment.
Precision alignment specialization
Verify by locality and institution.
Take on system commissioning.
Pressure test and sealing records.
Take on assembly and pressure testing of hydraulic and piping systems.
Hydraulic and piping specialization
Verify by locality and institution.
Carry out quality method training.
Inspection records and test reports.
Complete assembly inspection and testing according to protocol.
Inspection and testing specialization
Verify by locality and institution.
Carry out internal audit and training.
Quality checks and corrective action records.
Verify whether the assembly process and records conform to process requirements.
Quality support
Verify by locality and institution.
Maintain process standards.
Improvement records and validation data.
Analyze assembly problems and participate in process improvement.
Process improvement
Verify by locality and institution.
Take on production plan management.
Scheduling and progress records.
Coordinate materials, progress, and delivery.
Production coordination
Verify by locality and institution.
Develop toward education or management.
Training materials and case library.
Participate in internal training and codification of assembly experience.
Training and knowledge management
51-2031: 2025 employment 33,500, 2025—2035 decline 17.0%, average annual openings 2,100; openings still include replacements and are not net new additions or AI causality. Overall projections are not AI-causal and do not guarantee individual hiring.
United States
Changes reflect manufacturing assembly demand, but projections are not actual results.
Does not equal a personal employment guarantee, nor does it represent hiring volume at a particular region or enterprise.
Employment change
51-2031 Engine and Other Machine Assemblers
Employment size and openings are not the same indicator; openings include growth and replacements.
Statistics are for this occupation's own scope, but do not represent the workforce of a specific plant.
51-2031 Engine and Other Machine Assemblers
Average annual openings include growth and replacements, not net new additions or AI attribution.
Retain the projected occupational scope; does not indicate hiring volume at a given institution or a personal hiring probability.
51-2031 Engine and Other Machine Assemblers
An occupational overview cannot substitute for precise occupation-level statistics; refer to the original SOC table as noted.
2025—2035 original SOC table as noted; not AI-causal.
China industry wages are not U.S. openings.
A U.S. task profile is not a Chinese regulation.
Add production line workstation takt, standard work, and target components.
Assembly processes and collaboration can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add structural metal cutting, fabrication, and assembly welding and the corresponding safety qualifications.
Drawings and assembly verification can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add machine tool operation, cutting, tooling, and machining safety.
Dimensional measurement and drawings can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add in-service equipment fault diagnosis, overhaul, and energy isolation.
Mechanical structure and measurement can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add welding equipment processes, material joining, and legally licensed work.
Joining and quality verification can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add electrical and electronic components, wiring, and testing safety.
Process steps and inspection can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add electromechanical coupling, electrical connections, and system testing.
Assembly and interface verification can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
Add tool and die work, precision machining, materials, and heat treatment; do not describe the transfer as volume assembly.
Precision and drawings can be compared.
Editorial transfer reference; education, licensure, and hiring are verified separately.
2024 employment about 38,400, 2024—2034 projected change Decline (-1% or lower), projected openings about 2,800; openings include growth and replacements and do not equal a personal hiring probability.
The National Bureau of Statistics data checked this time are at industry-category scope, and no national single-occupation wage statistic precisely corresponding to this occupation was obtained; this page uses the average wage of urban units in "manufacturing" (2025 non-private 113,594 yuan/year, private 76,055 yuan/year) as an industry proxy, which can only illustrate industry background; it does not substitute an industry average or a single recruitment quote for the occupational wage.
In the U.S., typically a high school diploma or equivalent plus on-the-job training is required, and some positions require a postsecondary certificate; O*NET 51-2031.00 is Job Zone 1-2, and the education survey is mainly high school (64%), postsecondary certificate (13%), and less than high school (11%). Mainland China often requires a mechanical, electromechanical, or related educational background plus assembly experience.
Document verification and record organization tasks can be assisted by tools, but alignment, tightening, test running, and conformance determination remain the responsibility of assembly personnel with that duty; public sources are insufficient to conclude on changes in the number of positions.
Work in workshops on assembly and test running, possibly standing for long periods, carrying, and using tools, requiring protective measures according to protocol and attention to lifting and machinery safety.
They can only serve as a direction reference. The U.S. data are this occupation's own scope and mainland China is an industry proxy, and openings do not equal a hiring probability; actual requirements are subject to local protocols, enterprise rules, and job postings.
FermatMind research workflow
Source register and fact register for this page (O*NET 51-2031.00, BLS this-occupation-scope wages and projections, National Bureau of Statistics industry scope)
2026-10-11 (nine-module author check)
2025 U.S. single-occupation quintiles and 2025—2035 projections verified: 33500 / -17.0% / 2100, not attributed to AI. China's manufacturing pre-tax annual average is industry background only, and precise percentiles and AI measurements are missing; shared facts, Hero/SEO/FAQ, and duplicate ID conflicts are registered, and no full-page acceptance was performed.
Used to verify this occupation's tasks, scope, and preparation level; wages and employment are this occupation's own scope.
O*NET OnLine
United States
current page; accessed 2026-09-20
official occupation profile
exact occupation
Applies only to the occupational description of 51-2031.00 and does not represent local standards or enterprise rules.
2026-09-20
Used to verify work activities, tools, and Job Zone preparation level information.
O*NET OnLine
United States
current page; accessed 2026-09-20
official occupation details
exact occupation
Applies only to that occupational description and does not represent local standards or qualification requirements.
2026-09-20
Used to verify 2024 base-period employment, 2024—2034 change, and projected openings.
U.S. Bureau of Labor Statistics
United States
2024—2034 projections; accessed 2026-09-20
official employment projections
official projections
Projections are not actual results; openings include growth and replacements, and do not equal a hiring probability.
2026-09-20
Used to verify the median hourly wage and median annual wage, and the position within the national wage distribution.
U.S. Bureau of Labor Statistics
United States
May 2025 wage data; accessed 2026-09-20
official wage statistics
official wage statistics
Percentiles are not starting wages, and the statistical item differs from individual contractual pay.
2026-09-20
Used to explain the mainland China "manufacturing" industry average wage (non-private 113,594 yuan/year, private 76,055 yuan/year) as an industry background proxy.
National Bureau of Statistics
China
2025 annual data; accessed 2026-09-20
official aggregate wage statistics
industry proxy
The industry category scope covers multiple occupations and cannot substitute for this occupation's wage, nor is it a starting wage or median.
2026-09-20
Used to explain the internal scope for this page's field lengths, evidence tiers, gap markers, and source disclosure.
FermatMind
Global
current; accessed 2026-09-20
editorial source policy
editorial rule
An editorial rule, not a career data source.
2026-09-20