For spring lock washer, GB/T 5782 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.
GB/T 5782 — Scope
GB/T 5782 is "Fasteners — Hexagon head bolts — Product grades A and B". GB/T 5782 is the Chinese national adoption of the same document. 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
GB/T 5782 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 GB/T 5782
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Width b (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|---|
| M3 | 3.1 | 6.2 | 1.0 | 0.8 | GB/T 93 / DIN 127B |
| M4 | 4.1 | 7.6 | 1.2 | 1.0 | GB/T 93 / DIN 127B |
| M5 | 5.1 | 9.2 | 1.5 | 1.2 | GB/T 93 / DIN 127B |
| M6 | 6.1 | 11.8 | 2.0 | 1.6 | GB/T 93 / DIN 127B |
| M8 | 8.1 | 14.8 | 2.5 | 2.0 | GB/T 93 / DIN 127B |
| M10 | 10.2 | 18.1 | 3.0 | 2.5 | GB/T 93 / DIN 127B |
| M12 | 12.2 | 21.1 | 3.5 | 3.0 | GB/T 93 / DIN 127B |
| M14 | 14.2 | 24.1 | 4.0 | 3.5 | GB/T 93 / DIN 127B |
| M16 | 16.2 | 27.4 | 4.5 | 4.0 | GB/T 93 / DIN 127B |
| M18 | 18.2 | 29.4 | 5.0 | 4.5 | GB/T 93 / DIN 127B |
| M20 | 20.2 | 33.6 | 5.5 | 5.0 | GB/T 93 / DIN 127B |
| M24 | 24.5 | 40.1 | 6.5 | 6.0 | GB/T 93 / DIN 127B |
| M30 | 30.5 | 50.0 | 8.0 | 7.5 | GB/T 93 / DIN 127B |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify GB/T 5782
Choose GB/T 5782 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for spring lock washer — gb/t 5782 / iso 4014 (series 003).
Custom manufacturing · Made to drawing
Need a washer to this standard in a non-standard size?
Parts built to GB T 5782 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.
