Material specification page for structural washers, hardened (astm f436) in A2 Stainless Steel. Covers the grade designation (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to ASTM F436.
Why Choose A2 Stainless Steel for Structural Washers, Hardened (ASTM F436)
The most common stainless group for indoor and general outdoor fasteners. For structural washers, hardened (astm f436), 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 Structural Washers, Hardened (ASTM F436) 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 Structural Washers, Hardened (ASTM F436), 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
Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of Structural Washers, Hardened (ASTM F436) Available in A2 Stainless Steel
| For bolt size | Inner diameter (in) | Outer diameter (in) | Thickness (in) | Hardness (HRC) | Type | Finish | Reference standard |
|---|
