CNC Machining Standards Index
Drawings cite standards; standards drive every dimension, finish, and material callout on a part. This section is a working index: what each major standard actually covers, which clause you usually need, and how the international (ISO, ASME, ASTM), regional (DIN, JIS, EN), and national (GB) systems cross-reference.
Why this matters.
A drawing that cites “ISO 2768-mK” means a specific tolerance class on every uncited dimension. A drawing that cites “ASME Y14.5-2018” means Concentricity and Symmetry symbols are not to be used. If you don’t know the standard, you don’t know the part.
Tolerance & Geometry Standards
- ISO 2768 — General TolerancesPart 1 (linear/angular) and Part 2 (geometric), classes f / m / c / v, and the K/L/H suffix
- ISO 286 — Limits & FitsIT grades, fundamental deviations, the H7/g6 fit system, basis hole vs basis shaft
- ASME Y14.5 — GD&T (2018)The 14 symbols (now 12, after 2018 removed Concentricity and Symmetry), datum schemes, MMC/LMC modifiers
- ISO 1101 — Geometrical TolerancingThe ISO counterpart to ASME Y14.5, with the key differences called out side-by-side
- GB/T 1804 — Chinese General TolerancesThe Chinese national mirror of ISO 2768, with the four classes and the notes on applicability
Surface & Texture Standards
- ISO 4287 — Surface Roughness TermsDefinitions of Ra, Rz, Rq, Rmax, Rp, Rv, Rt — the parameters behind every surface callout
- ISO 1302 — Surface Texture CalloutsThe checkmark / triangle symbol, machining vs no-removal, all-on-one-page reference
- ASME B46.1 — Surface Texture (US)The US counterpart to ISO 4287/1302, with conversion notes for drawings dual-cited to both systems
Material Standards
- ASTM Steel Specs (A-series)A36, A108, A311, A519, A681 — which ASTM covers which steel product form
- ASTM Aluminum & Magnesium (B209, B211, B221)Plate, sheet, bar, and extrusion specs for 6061, 7075, 2024, 5052 and friends
- SAE AMS Aerospace Material SpecsAMS 4928 (Ti-6Al-4V), AMS 2750 (pyrometry), AMS-QQ-A-250 — the callouts that show up on aerospace drawings
- EN 10027 — European Steel DesignationHow to read S355J2+N, 42CrMo4, X5CrNi18-10 — the European naming system decoded
Heat Treatment, Coating & Quality
- AMS 2750 — Pyrometry (Heat Treat Furnaces)Temperature uniformity, instrument calibration, system — the spec that governs Nadcap HT approval
- MIL-A-8625 — Anodizing (Type I/II/III)The US military spec still cited on aerospace and defense drawings, with type and class meanings
- ISO 9001 / AS9100 / IATF 16949 / ISO 13485The four QMS standards: what each adds on top of ISO 9001, and which industry each is for
- AS9102 — First Article InspectionThe FAI report format used in aerospace, with the three forms and the balloon numbering method
Material Certification
Reading standards.
Most standards cost money, but the scope clause and the table of contents are usually available free from ISO/ASME. We cite the clause numbers we use, so even without buying the full standard you can usually find what you need from the public scope + Wikipedia + this wiki. Always cite the standard and the edition year on your drawing.