Engineering Japanese: 仕様, 公差, 図面, 検査
The reader can read engineering Japanese by connecting specifications, drawings, tolerances, inspection, and requirements.
Core examples: 仕様, 公差, 図面, 検査, 寸法, 材質, 要件, 試作, 設計変更, 試験条件.
Ordinary nouns become measurable requirements
An engineering document says:
仕様を満たすこと。 図面の寸法公差に従うこと。 試験条件は別紙の通りとする。
The words look like normal nouns: specification, drawing, dimension, test. But in engineering, they define requirements, acceptance criteria, and evidence. If you treat them as descriptive only, you miss obligation.
The key principle is:
Engineering Japanese turns language into technical constraints.
Every noun phrase may define what must be built, measured, tested, or accepted.
仕様: specification
仕様
means specification.
Related:
仕様書 specification document
要求仕様 required specification
製品仕様 product specification
仕様変更 specification change
仕様 defines required characteristics. It is not a casual description.
Learner action: when 仕様 appears, ask what property, function, or condition must be satisfied.
図面 and drawing references
図面
means drawing/technical drawing.
Related:
図番 drawing number
部品図 part drawing
組立図 assembly drawing
断面図 cross-sectional view
A drawing may define dimensions, materials, tolerances, notes, and surface treatment.
Learner action: figure out whether the text is referring to a drawing as authority.
寸法 and 公差
寸法
means dimension.
公差
means tolerance.
Example:
寸法公差 dimensional tolerance
A part may be rejected if it is outside tolerance.
Learner action: engineering Japanese often requires reading numbers and units as part of grammar.
材質
材質
means material.
Related:
材料 material
表面処理 surface treatment
硬度 hardness
強度 strength
Material specification affects performance, cost, test method, and compliance.
要件
要件
means requirement.
Related:
機能要件 functional requirement
非機能要件 non-functional requirement
必須要件 mandatory requirement
In software and systems engineering, 要件 may be more central than 仕様.
Learner action: identify whether 要件 is user/business requirement or technical requirement.
検査 and 試験
検査
means inspection.
試験
means test.
Related:
試験条件 test condition
試験結果 test result
受入検査 receiving/acceptance inspection
出荷検査 shipment inspection
Inspection often checks conformance. Testing may evaluate performance under conditions.
試作
試作
means prototype/trial production.
Related:
試作品 prototype
量産 mass production
量産試作 mass-production trial
Prototype language appears before full production.
Learner action: distinguish prototype status from final product.
設計変更
設計変更
means design change.
Related:
変更申請 change request
変更履歴 change history
改訂 revision
A design change can affect drawings, specifications, parts, tests, cost, and schedule.
Learner action: identify revision level and effective date.
Example bank walkthrough
仕様
Specification.
Learner action: required characteristics.
公差
Tolerance.
Learner action: allowable variation.
図面
Technical drawing.
Learner action: source of dimensions/requirements.
検査
Inspection.
Learner action: conformance check.
寸法
Dimension.
Learner action: measurement item.
材質
Material.
Learner action: technical property.
要件
Requirement.
Learner action: system/function/business constraint.
試作
Prototype/trial production.
Learner action: development stage.
設計変更
Design change.
Learner action: revision and impact.
試験条件
Test condition.
Learner action: requirements for valid test.
Engineering-document pass
When reading engineering Japanese:
- Object: part, system, software, material?
- Requirement: 仕様 or 要件.
- Drawing reference: 図面, 図番.
- Dimension and tolerance.
- Material or surface condition.
- Test/inspection method.
- Acceptance judgment.
- Prototype or production status.
- Design-change history.
- Effective date/version.
Requirement strength table
Engineering documents often vary in force.
| Phrase | Likely force |
|---|---|
| 〜すること | requirement/instruction |
| 〜しなければならない | mandatory |
| 〜してはならない | prohibited |
| 〜が望ましい | desirable/recommended |
| 〜を推奨する | recommended |
| 参考 | reference only |
| 別紙による | governed by attached document |
| 図面に従う | follow drawing |
This helps separate binding requirements from notes.
Drawing authority warning
A sentence such as 図面による, 図面の通り, or 図面に従う means the drawing is not illustration. It is the controlling technical source.
Check:
- drawing number,
- revision,
- dimension,
- tolerance,
- material,
- surface treatment,
- notes,
- referenced standards.
Change-control language
設計変更 is not just “we changed the design.” It may require:
- change request,
- approval,
- revision update,
- affected parts list,
- effective lot/date,
- test confirmation,
- customer approval.
Look for 改訂, 変更履歴, 承認, 適用開始, and 対象ロット.
A strong tool for this article would turn engineering prose into requirement cards.
Suggested functions:
- Requirement highlighter: 仕様, 要件.
- Drawing-reference detector.
- Dimension/tolerance visualizer.
- Material field extraction.
- Test-condition parser.
- Design-change tracker.
- Engineering caution label.
Final rule
Engineering Japanese is not merely descriptive. It is prescriptive.
仕様 tells what must be true. 図面 tells where requirements live. 寸法 and 公差 define measurable boundaries. 検査 and 試験 decide whether the item passes. 設計変更 changes the target.
Read technical nouns as constraints.
Related reading
National Language Policy and the Idea of Kokugo
The reader can understand kokugo as a national-language idea with educational, political, and cultural consequences.
Tracking Japanese Listening Progress With Real Audio
The reader can track Japanese listening progress using real audio, transcripts, comprehension targets, error categories, and repeated measurement.
Designing Japanese Anki Cards for Kanji, Vocabulary, Pitch, and Context
The reader can design Japanese Anki cards that train recognition, production, kanji, vocabulary, pitch accent, and context without creating bloated review debt.
When Japanese Uses Spaces: Children’s Books, Teaching Materials, and UI
The reader can recognize the few contexts where Japanese uses spaces and understand what spacing reveals about audience, pedagogy, and interface design.
When CJK Comparison Helps Learners and When It Becomes Noise
The reader can decide when CJK comparison accelerates Japanese learning and when it creates noise, overconfidence, or bad habits.
Tokyo Pitch Accent Patterns: Heiban, Atamadaka, Nakadaka, Odaka
The reader can classify common Tokyo pitch accent patterns and connect labels to what the ear actually hears.