The table below lists the dimensions catalogued for hex nut, fine pitch under GB/T 6171. The scope of GB/T 6171 itself is not summarised here — where a figure matters, confirm it against the published document.
GB/T 6171 — Scope
The table below lists the dimensions catalogued for hex nut, fine pitch — gb/t 6171 / iso 8673 (series 067) under GB/T 6171. The scope of GB/T 6171 itself is not summarised here — where a figure matters, confirm it against the published document.
Tolerance & Product Grades
Product grade is a concept from dimensional fastener standards and does not apply to GB/T 6171. Tolerances for this part are the limits shown against each dimension in the table.
Dimensions Specified by GB/T 6171
| 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 |
Companion Standards
A complete specification for hex nut, fine pitch — gb/t 6171 / iso 8673 (series 067) normally cites several documents: one for the geometry, one for the material or mechanical properties, and one for the finish. GB/T 6171 is one of them, not all of them.
When to Specify GB/T 6171
Choose GB/T 6171 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for hex nut, fine pitch — gb/t 6171 / iso 8673 (series 067).
Custom manufacturing · Made to drawing
Need a nut to this standard in a non-standard size?
Parts built to GB T 6171 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
