ISO 4014 is the standard cited for general flat washer. This page sets out what the standard controls for this part, reproduces the dimensional table supplied against it, and notes the related designations referenced on drawings.
ISO 4014 — Scope
ISO 4014 is "Fasteners — Hexagon head bolts — Product grades A and B". It covers M1.6 to M64. Partly threaded. The fully threaded equivalent is ISO 4017.
Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.
Tolerance & Product Grades
ISO 4014 defines product grades A and B. The grade sets how closely the finished part has to follow the nominal dimensions; it is not a strength rating.
Dimensions Specified by ISO 4014
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|
| M3 | 3.2 | 7.0 | 0.5 | ISO 7089 / GB/T 97.1 |
| M4 | 4.3 | 9.0 | 0.8 | ISO 7089 / GB/T 97.1 |
| M5 | 5.3 | 10.0 | 1.0 | ISO 7089 / GB/T 97.1 |
| M6 | 6.4 | 12.0 | 1.6 | ISO 7089 / GB/T 97.1 |
| M8 | 8.4 | 16.0 | 1.6 | ISO 7089 / GB/T 97.1 |
| M10 | 10.5 | 20.0 | 2.0 | ISO 7089 / GB/T 97.1 |
| M12 | 13.0 | 24.0 | 2.5 | ISO 7089 / GB/T 97.1 |
| M14 | 15.0 | 28.0 | 2.5 | ISO 7089 / GB/T 97.1 |
| M16 | 17.0 | 30.0 | 3.0 | ISO 7089 / GB/T 97.1 |
| M18 | 19.0 | 34.0 | 3.0 | ISO 7089 / GB/T 97.1 |
| M20 | 21.0 | 37.0 | 3.0 | ISO 7089 / GB/T 97.1 |
| M24 | 25.0 | 44.0 | 4.0 | ISO 7089 / GB/T 97.1 |
| M30 | 31.0 | 56.0 | 4.0 | ISO 7089 / GB/T 97.1 |
| M36 | 37.0 | 66.0 | 5.0 | ISO 7089 / GB/T 97.1 |
Companion Standards
ISO 4014 controls only the geometry of general flat washer — gb/t 5782 / iso 4014 (series 008). The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards such as ISO 4042 for electroplating. For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
When to Specify ISO 4014
Choose ISO 4014 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for general flat washer — gb/t 5782 / iso 4014 (series 008).
Custom manufacturing · Made to drawing
Need a washer to this standard in a non-standard size?
Parts built to ISO 4014 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.
