Material specification page for spring lock washers in A4 Stainless Steel. Covers the grade designation (A4-80 (316)), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to ISO 7980 / DIN 127.
Why Choose A4 Stainless Steel for Spring Lock Washers
Specified for marine, coastal and chemical applications. For spring lock washers, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | A4-80 (316) |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C |
| 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 Washers in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Spring Lock Washers, the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.
Sizes of Spring Lock Washers Available in A4 Stainless Steel
| For bolt size | Inner diameter d1 min (mm) | Outer diameter d2 max (mm) | Width b (mm) | Thickness s (mm) | Reference standard |
|---|---|---|---|---|---|
| M2 | 2.1 | 4.4 | 1.6 | 0.5 | ISO 7980 / DIN 127 |
| M2.5 | 2.6 | 5.1 | 2.0 | 0.6 | ISO 7980 / DIN 127 |
| M3 | 3.1 | 6.2 | 2.0 | 0.8 | ISO 7980 / DIN 127 |
| M3.5 | 3.6 | 7.0 | 2.5 | 0.8 | ISO 7980 / DIN 127 |
| M4 | 4.1 | 7.6 | 2.5 | 1.0 | ISO 7980 / DIN 127 |
| M5 | 5.1 | 9.2 | 3.0 | 1.2 | ISO 7980 / DIN 127 |
| M6 | 6.1 | 11.8 | 4.0 | 1.6 | ISO 7980 / DIN 127 |
| M7 | 7.1 | 13.1 | 4.0 | 1.6 | ISO 7980 / DIN 127 |
| M8 | 8.1 | 14.8 | 5.0 | 2.0 | ISO 7980 / DIN 127 |
| M10 | 10.2 | 18.1 | 6.0 | 2.2 | ISO 7980 / DIN 127 |
| M12 | 12.2 | 21.1 | 7.0 | 2.5 | ISO 7980 / DIN 127 |
| M14 | 14.2 | 24.1 | 8.0 | 3.0 | ISO 7980 / DIN 127 |
| M16 | 16.2 | 27.4 | 9.0 | 3.5 | ISO 7980 / DIN 127 |
| M18 | 18.2 | 29.4 | 9.0 | 3.5 | ISO 7980 / DIN 127 |
| M20 | 20.2 | 33.6 | 10.0 | 4.0 | ISO 7980 / DIN 127 |
| M22 | 22.5 | 35.9 | 11.0 | 4.0 | ISO 7980 / DIN 127 |
| M24 | 24.5 | 40.1 | 12.0 | 5.0 | ISO 7980 / DIN 127 |
| M27 | 27.5 | 44.8 | 12.0 | 5.0 | ISO 7980 / DIN 127 |
| M30 | 30.5 | 50.0 | 14.0 | 6.0 | ISO 7980 / DIN 127 |
| M36 | 36.5 | 60.0 | 16.0 | 7.0 | ISO 7980 / DIN 127 |

