For round head grooved pins, ISO 8746 is the governing document for the dimensions listed below. Mechanical and performance requirements for this part family are set by its own standards, not by the bolt and screw property-class documents.
ISO 8746 — Scope
ISO 8746 is "Grooved pins with round head".
Tolerance & Product Grades
ISO 8746 does not divide round head grooved pins into product grades. Tolerances are given as limits on the individual dimensions in the table.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by ISO 8746
| Nominal diameter d (mm) | d_1_max (mm) | d_1_min (mm) | d_k_max (mm) | d_k_min (mm) | k_max (mm) | k_min (mm) | r (mm) | c (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|
| 1.4 mm | 1.4 | 1.35 | 2.6 | 2.2 | 0.9 | 0.7 | 1.4 | 0.42 | 3~6 | ISO 8746 |
| 1.6 mm | 1.6 | 1.55 | 3 | 2.6 | 1.1 | 0.9 | 1.6 | 0.48 | 3~8 | ISO 8746 |
| 2 mm | 2 | 1.95 | 3.7 | 3.3 | 1.3 | 1.1 | 1.9 | 0.6 | 3~10 | ISO 8746 |
| 2.5 mm | 2.5 | 2.425 | 4.6 | 4.2 | 1.6 | 1.4 | 2.4 | 0.75 | 3~12 | ISO 8746 |
| 3 mm | 3 | 2.925 | 5.45 | 4.95 | 1.95 | 1.65 | 2.8 | 0.9 | 4~16 | ISO 8746 |
| 4 mm | 4 | 3.9 | 7.75 | 6.75 | 2.55 | 2.25 | 3.8 | 1.2 | 5~20 | ISO 8746 |
| 5 mm | 5 | 4.9 | 9.1 | 8.5 | 3.15 | 2.85 | 4.6 | 1.5 | 6~25 | ISO 8746 |
| 6 mm | 6 | 5.9 | 10.8 | 10.2 | 3.75 | 3.45 | 5.7 | 1.8 | 8~30 | ISO 8746 |
| 8 mm | 8 | 7.85 | 14.4 | 13.6 | 5 | 4.6 | 7.5 | 2.4 | 10~40 | ISO 8746 |
| 10 mm | 10 | 9.85 | 16 | 14.9 | 7.4 | 6.5 | 8 | 3 | 12~40 | ISO 8746 |
| 12 mm | 12 | 11.8 | 19 | 17.7 | 8.4 | 7.5 | 9.5 | 3.6 | 16~40 | ISO 8746 |
| 16 mm | 16 | 15.8 | 25 | 23.7 | 10.9 | 10 | 13 | 4.8 | 20~40 | ISO 8746 |
| 20 mm | 20 | 19.8 | 32 | 30.7 | 13.9 | 13 | 16.5 | 6 | 25~40 | ISO 8746 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Round Head Grooved Pins page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify ISO 8746
Choose ISO 8746 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for round head grooved pins.
Custom manufacturing · Made to drawing
Need a pin to this standard in a non-standard size?
Parts built to ISO 8746 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 turning.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
