Material page for epdm sealing washers in A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is good general corrosion resistance and the service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A2 Stainless Steel for EPDM Sealing Washers
The most common stainless group for indoor and general outdoor fasteners. For epdm sealing washers, 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 EPDM Sealing Washers in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Comparable Grades
For EPDM Sealing Washers, the alternative stainless grade is A4 (316). 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 EPDM Sealing Washers Available in A2 Stainless Steel
| Screw size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Total thickness s (mm) | EPDM thickness (mm) | Backing material | Temperature range (deg C) | Reference standard |
|---|---|---|---|---|---|---|---|
| No.8 (4.2 mm) | 4.3 | 11 | 2.0 | 1.0 | Galvanised steel | -40 to +130 | Industry standard |
| No.10 (4.8 mm) | 5.0 | 14 | 2.0 | 1.0 | Galvanised steel | -40 to +130 | Industry standard |
| No.12 (5.5 mm) | 5.6 | 16 | 2.5 | 1.5 | Galvanised steel | -40 to +130 | Industry standard |
| No.14 (6.3 mm) | 6.4 | 19 | 2.5 | 1.5 | Galvanised steel | -40 to +130 | Industry standard |
| M6 | 6.4 | 19 | 2.5 | 1.5 | A2 stainless | -40 to +130 | Industry standard |
| M8 | 8.4 | 22 | 3.0 | 2.0 | A2 stainless | -40 to +130 | Industry standard |
| M10 | 10.5 | 25 | 3.0 | 2.0 | A2 stainless | -40 to +130 | Industry standard |
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.
