For flat washers for clevis pins, ISO 8738 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 8738 — Scope
ISO 8738 is "Plain washers for clevis pins — Product grade A".
Tolerance & Product Grades
ISO 8738 is written to product grade A; a different grade of the same part is a different document in the family, not a variant of this one.
Dimensions Specified by ISO 8738
| Size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness h (mm) | h_max (mm) | Reference standard |
|---|---|---|---|---|---|
| M3 | 3 | 6 | 0.8 | 0.84 | ISO 8738 |
| M4 | 4 | 8 | 0.8 | 0.84 | ISO 8738 |
| M5 | 5 | 10 | 0.8 | 0.84 | ISO 8738 |
| M6 | 6 | 12 | 1.6 | 1.68 | ISO 8738 |
| M7 | 7 | 14 | 1.6 | 1.68 | ISO 8738 |
| M8 | 8 | 16 | 2 | 2.1 | ISO 8738 |
| M10 | 10 | 20 | 2.5 | 2.625 | ISO 8738 |
| M12 | 12 | 25 | 3 | 3.15 | ISO 8738 |
| M13 | 13 | 25 | 3 | 3.15 | ISO 8738 |
| M14 | 14 | 28 | 3 | 3.15 | ISO 8738 |
| M16 | 16 | 28 | 3 | 3.15 | ISO 8738 |
| M18 | 18 | 30 | 4 | 4.2 | ISO 8738 |
| M20 | 20 | 32 | 4 | 4.2 | ISO 8738 |
| M22 | 22 | 34 | 4 | 4.2 | ISO 8738 |
| M23 | 23 | 36 | 4 | 4.2 | ISO 8738 |
| M24 | 24 | 38 | 4 | 4.2 | ISO 8738 |
| M25 | 25 | 40 | 4 | 4.2 | ISO 8738 |
| M26 | 26 | 40 | 5 | 5.25 | ISO 8738 |
| M27 | 27 | 40 | 5 | 5.25 | ISO 8738 |
| M28 | 28 | 42 | 5 | 5.25 | ISO 8738 |
| M30 | 30 | 45 | 5 | 5.25 | ISO 8738 |
| M32 | 32 | 50 | 5 | 5.25 | ISO 8738 |
| M33 | 33 | 50 | 5 | 5.25 | ISO 8738 |
| M35 | 35 | 52 | 6 | 6.3 | ISO 8738 |
| M36 | 36 | 52 | 6 | 6.3 | ISO 8738 |
| M40 | 40 | 58 | 6 | 6.3 | ISO 8738 |
| M45 | 45 | 62 | 7 | 7.35 | ISO 8738 |
| M50 | 50 | 68 | 8 | 8.4 | ISO 8738 |
| M55 | 55 | 75 | 9 | 9.45 | ISO 8738 |
| M60 | 60 | 80 | 9 | 9.45 | ISO 8738 |
| M65 | 65 | 90 | 9 | 9.45 | ISO 8738 |
| M70 | 70 | 95 | 10 | 10.5 | ISO 8738 |
| M75 | 75 | 100 | 10 | 10.5 | ISO 8738 |
| M80 | 80 | 110 | 12 | 12.6 | ISO 8738 |
| M85 | 85 | 110 | 12 | 12.6 | ISO 8738 |
| M90 | 90 | 115 | 12 | 12.6 | ISO 8738 |
| M95 | 95 | 120 | 12 | 12.6 | ISO 8738 |
| M100 | 100 | 125 | 14 | 14.7 | ISO 8738 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Flat Washers for Clevis Pins page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify ISO 8738
Choose ISO 8738 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for flat washers for clevis pins.
Custom manufacturing · Made to drawing
Need a washer to this standard in a non-standard size?
Parts built to ISO 8738 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 stamping or punching.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
