A2 Stainless Steel Flat Washers, Extra Large Series are supplied to ISO 7094. The grade provides good general corrosion resistance and is largely non-magnetic; the practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint. Property data, grade comparison and the full size table follow.
Why Choose A2 Stainless Steel for Flat Washers, Extra Large Series
The most common stainless group for indoor and general outdoor fasteners. For flat washers, extra large series, this matters when good general corrosion resistance is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Good general corrosion resistance |
Corrosion Behavior in Service
A2 (304) gives excellent atmospheric and most-water corrosion resistance and is the most common stainless for Flat Washers, Extra Large Series in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Galvanic & Galling Considerations
For stainless flat washers, extra large series the compatibility question is galvanic rather than galling: joined to aluminum or galvanized steel in wet service, stainless drives corrosion of the less-noble metal. Isolate with a coating, sleeve or non-conductive washer where the joint sees moisture. Note also that stainless is softer than hardened carbon steel, so where the part carries a wear or shear duty, check the load against the grade before substituting.
Using Stainless Fasteners in Aluminum
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Flat Washers, Extra Large Series Available in A2 Stainless Steel
| Size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness h (mm) | h_max (mm) | Reference standard |
|---|---|---|---|---|---|
| M5 | 5.5 | 18.0 | 2.0 | 2.3 | ISO 7094 |
| M6 | 6.6 | 22.0 | 2.0 | 2.3 | ISO 7094 |
| M8 | 9.0 | 28.0 | 3.0 | 3.6 | ISO 7094 |
| M10 | 11.0 | 34.0 | 3.0 | 3.6 | ISO 7094 |
| M12 | 13.5 | 44.0 | 4.0 | 4.6 | ISO 7094 |
| (M14) | 15.5 | 50.0 | 4.0 | 4.6 | ISO 7094 |
| M16 | 17.5 | 56.0 | 5.0 | 6.0 | ISO 7094 |
| (M18) | 20.0 | 60.0 | 5.0 | 6.0 | ISO 7094 |
| M20 | 22.0 | 72.0 | 6.0 | 7.0 | ISO 7094 |
| (M22) | 24.0 | 80.0 | 6.0 | 7.0 | ISO 7094 |
| M24 | 26.0 | 85.0 | 6.0 | 7.0 | ISO 7094 |
| (M27) | 30.0 | 98.0 | 6.0 | 7.0 | ISO 7094 |
| M30 | 33.0 | 105.0 | 6.0 | 7.0 | ISO 7094 |
| (M33) | 36.0 | 115.0 | 8.0 | 9.2 | ISO 7094 |
| M36 | 39.0 | 125.0 | 8.0 | 9.2 | ISO 7094 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this washer in a grade that is not listed?
A2 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.
