Comparison
ASME Y14.100 and Y14.5: What Each Covers
The Short Answer
One Family, Different Jobs
The ASME Y14 series is the family of standards for engineering product definition. Y14.100 is the base standard for drawings, and it expects the specialty standards to be used with it. Y14.5 is the best known of those, because it is the rulebook for geometric dimensioning and tolerancing (GD&T). The two are not alternatives: one tells you how to prepare the drawing, the other how to state a tolerance on it.
These standards are sold by ASME, so this page summarizes scope from the catalog descriptions and does not reproduce their text. Editions below are those ASME lists as of 4 November 2026; the edition that governs your work is the one your contract cites.
What Each Governs
The Y14 Standards You Meet Most
- ASME Y14.100, Engineering Drawing Practices
- The base standard for the drawing itself. It sets the essential requirements for preparing and revising engineering drawings and associated lists, and it is meant to be used with the specialty standards below. ASME lists the 2017 edition as the latest.
- ASME Y14.5, Dimensioning and Tolerancing
- The language of geometric dimensioning and tolerancing (GD&T): symbols, rules, definitions, and defaults for stating a part's allowable variation and interpreting it. ASME lists 2018 as the latest edition, and a revision is in progress.
- ASME Y14.24, Types and Applications of Engineering Drawings
- Defines the types of drawing most often used to establish engineering requirements, such as detail, assembly, and installation drawings. The latest listed edition is 2020.
- ASME Y14.34, Associated Lists
- Covers the lists that travel with drawings, such as parts lists. The latest listed edition is 2013.
- ASME Y14.35, Revision of Engineering Product Definition Datasets and Associated Documents
- How revisions to drawings, datasets, and associated documents are made and recorded. The 2025 edition is the latest listed.
- ASME Y14.41, Digital Product Definition Data Practices
- Requirements for preparing and revising digital product definition data: the annotated 3D model as the definition. ASME lists the 2026 edition as the latest.
- ASME Y14.47, Model Organization Practices
- How a 3D model and its related information are organized in a digital product definition data set. The latest edition found is 2023.
In a Package
How They Fit a Technical Data Package
A technical data package (TDP) is the authoritative technical definition of an item. MIL-STD-31000 defines what a TDP contains and leaves the drawing rules to ASME. Its Type 2D package is built on drawings that follow the ASME Y14.100 series; its Type 3D package is built on annotated models, and revision A added a model organizational schema compliant with Y14.41. For the package itself, see what a technical data package is.
For an auditor or a buyer, the useful question is which standards the contract names and at which edition. The drawing set should show it: types per Y14.24, lists per Y14.34, tolerances per Y14.5, revisions per Y14.35. Our technical data package audit guide covers how to test a package against what was ordered.
Downstream
Drawings and Technical Manuals
Technical manuals are not part of a TDP, and nothing in the Y14 series tells a writer how to build a manual. The link is practical. Manual illustrations and parts data are derived from engineering data, so a clear drawing with a complete list gives the illustrator what is needed, and an ambiguous one passes the ambiguity downstream. See technical illustration for technical manuals for how that derivation works and how S1000D identifies illustrations.
The Shift
From Drawings to the Model
Y14.41 and Y14.47 are the model-era members of the family. Y14.41 sets how the digital product definition is prepared and revised; Y14.47 sets how the model and its related information are organized. Under a model-based approach the annotated 3D model, not a drawing, is the controlled record. Drawings may still be produced from it, and they must agree with it. Read what model-based definition is and model-based technical data for the standards behind it. Whether a given model is authoritative on a given program is a contract question; read the contract text.
FAQ
Questions We Hear
What is the difference between ASME Y14.100 and Y14.5?
Y14.100 governs how an engineering drawing is prepared and revised: the general practices for the drawing and its associated lists. Y14.5 governs one thing on it, how dimensions and tolerances are stated and read, including GD&T symbols. A drawing needs both, and Y14.100 points to the specialty standards rather than repeating them.
What is the latest edition of ASME Y14.100?
ASME's catalog lists Y14.100-2017 as the latest edition, with 2013 and 2004 before it. Your contract decides which edition applies, so read the revision it cites instead of assuming the newest.
Does a model-based program still need Y14.100 and Y14.5?
Often yes, in part. Y14.41 and Y14.47 cover the digital product definition and the model, and dimensioning and tolerancing rules still apply to what the model states. Derived drawings supplied alongside a model must agree with it. What your program owes is set by its contract.
How do these standards relate to MIL-STD-31000?
MIL-STD-31000 defines the technical data package and what it contains; it does not restate the drawing rules. A Type 2D package is built on drawings that follow the ASME Y14.100 series, and the standard's model-based provisions were aligned with Y14.41 from revision A. Our MIL-STD-31000 page has the revision history.
Are Y14 standards required in technical manuals?
No. Technical manuals are written against their own standards, and MIL-STD-31000C says manuals are not a TDP element. Manual illustrations are usually derived from the engineering data, so the drawings and models upstream still shape what the illustrator can draw.
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Manuals Start With Good Engineering Data
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