Material specification page for spring lock washer in A4 Stainless Steel. Covers the grade designation (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to GB/T 5782 / ISO 4014.
Why Choose A4 Stainless Steel for Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003)
Specified for marine, coastal and chemical applications. For spring lock washer — gb/t 5782 / iso 4014 (series 003), this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003), the alternative stainless grade is A2 (304). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
Using Stainless Fasteners in Aluminum
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of Spring Lock Washer — GB/T 5782 / ISO 4014 (Series 003) Available in A4 Stainless Steel
| 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 |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this washer in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Bearing area is usually the reason for a special washer: a larger outside diameter to spread load into a softer material, or a thicker section to resist dishing. Made by stamping or punching.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

