For tab washers (din 93 / din 463) in A2 Stainless Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70) is summarized below together with every size supplied.
Why Choose A2 Stainless Steel for Tab Washers (DIN 93 / DIN 463)
The most common stainless group for indoor and general outdoor fasteners. For tab washers (din 93 / din 463), 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 Tab Washers (DIN 93 / DIN 463) 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 tab washers (din 93 / din 463) 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
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 Tab Washers (DIN 93 / DIN 463) Available in A2 Stainless Steel
| For bolt size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Tab length (mm) | Form | Material | Reference standard |
|---|---|---|---|---|---|---|---|
| M6 | 6.4 | 14.0 | 0.8 | 8 | Single tab (DIN 93) | Mild steel | DIN 93 |
| M8 | 8.4 | 18.0 | 1.0 | 10 | Single tab (DIN 93) | Mild steel | DIN 93 |
| M10 | 10.5 | 22.0 | 1.0 | 12 | Single tab (DIN 93) | Mild steel | DIN 93 |
| M12 | 13.0 | 26.0 | 1.25 | 14 | Single tab (DIN 93) | Mild steel | DIN 93 |
| M16 | 17.0 | 32.0 | 1.5 | 16 | Single tab (DIN 93) | Mild steel | DIN 93 |
| M20 | 21.0 | 40.0 | 2.0 | 20 | Single tab (DIN 93) | Mild steel | DIN 93 |
