ISO 4032 covers the dimensional requirements for hex nut. Reproduced below: the complete size table, the tolerance grades, and the companion and equivalent standards referenced when ordering to this document.
ISO 4032 — Scope
ISO 4032 specifies the dimensions and tolerances of hex nut — gb/t 6170 / iso 4032 (series 066). Material, property class, surface finish and packaging are governed by separate documents in the same standards family (for example ISO 898-1 for the mechanical property classes of bolts and screws).
Tolerance & Product Grades
ISO 4032, alongside the related GB/T 6170 / ISO 4032 entries on this site, specifies product grades (typically A or B for fine work and C for general engineering) and tolerance classes for the controlling dimensions. Choose the grade against the precision your application requires.
Dimensions Specified by ISO 4032
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Reference standard |
|---|---|---|---|---|---|
| M3 | 0.5 | 5.5 | 6.01 | 2.4 | ISO 4032 / GB/T 6170 |
| M4 | 0.7 | 7.0 | 7.66 | 3.2 | ISO 4032 / GB/T 6170 |
| M5 | 0.8 | 8.0 | 8.79 | 4.7 | ISO 4032 / GB/T 6170 |
| M6 | 1.0 | 10.0 | 11.05 | 5.2 | ISO 4032 / GB/T 6170 |
| M8 | 1.25 | 13.0 | 14.38 | 6.8 | ISO 4032 / GB/T 6170 |
| M10 | 1.5 | 16.0 | 17.77 | 8.4 | ISO 4032 / GB/T 6170 |
| M12 | 1.75 | 18.0 | 20.03 | 10.8 | ISO 4032 / GB/T 6170 |
| M14 | 2.0 | 21.0 | 23.36 | 12.8 | ISO 4032 / GB/T 6170 |
| M16 | 2.0 | 24.0 | 26.75 | 14.8 | ISO 4032 / GB/T 6170 |
| M18 | 2.5 | 27.0 | 30.14 | 15.8 | ISO 4032 / GB/T 6170 |
| M20 | 2.5 | 30.0 | 33.53 | 18.0 | ISO 4032 / GB/T 6170 |
| M24 | 3.0 | 36.0 | 39.98 | 21.5 | ISO 4032 / GB/T 6170 |
| M30 | 3.5 | 46.0 | 50.85 | 25.6 | ISO 4032 / GB/T 6170 |
| M36 | 4.0 | 55.0 | 60.79 | 31.0 | ISO 4032 / GB/T 6170 |
Equivalent Standards
ISO 4032 hex nuts correspond to DIN 934 (style 1).
When to Specify ISO 4032
Choose ISO 4032 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for hex nut — gb/t 6170 / iso 4032 (series 066).