Split Cotter Pins manufactured to ISO 1234 follow a specific scope. This page summarizes that scope, lists every dimension the standard fixes, and points to the most common cross-references.
ISO 1234 — Scope
ISO 1234 specifies the dimensions and tolerances of split cotter pins. 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 1234, alongside the related ISO 1234 / DIN 94 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 1234
| Nominal diameter (mm) | Hole dia min (mm) | Hole dia max (mm) | Common length range (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| 0.6 | 0.7 | 0.9 | 6~16 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 0.8 | 0.9 | 1.1 | 6~20 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 1.0 | 1.1 | 1.3 | 8~25 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 1.2 | 1.3 | 1.5 | 8~30 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 1.6 | 1.7 | 1.9 | 10~40 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 2.0 | 2.1 | 2.4 | 12~50 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 2.5 | 2.7 | 3.0 | 14~63 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 3.2 | 3.4 | 3.8 | 18~80 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 4.0 | 4.3 | 4.8 | 22~100 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 5.0 | 5.4 | 5.9 | 25~125 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 6.3 | 6.7 | 7.4 | 32~160 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 8.0 | 8.5 | 9.3 | 40~200 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 10.0 | 10.6 | 11.5 | 50~250 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
| 13.0 | 13.8 | 14.9 | 63~315 | Low-carbon steel / stainless | ISO 1234 / DIN 94 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Split Cotter Pins page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
ISO 1234 controls only the geometry of split cotter pins. The mechanical strength is set by ISO 898-1 (bolts and screws) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards (e.g. ISO 4042 for electroplating). For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).