A2 Stainless Steel Turn-Button Fastener Bases are supplied to Trade series (turn-button fastener bases). 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 Turn-Button Fastener Bases
The most common stainless group for indoor and general outdoor fasteners. For turn-button fastener bases, 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 Turn-Button Fastener Bases 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 turn-button fastener bases 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 Turn-Button Fastener Bases Available in A2 Stainless Steel
| Base form | Base dimensions (in) | Screw | Hole spacing (in) | Mounting holes | Material | Mating part |
|---|---|---|---|---|---|---|
| single-stud | 1-1/4 u00d7 1/2 u00d7 11/16 | No. 6 | 7/8 | two | nickel-plated brass | turn-button eyelet |
| double-stud | 1-1/4 u00d7 1/2 u00d7 7/8 | No. 8 | two | nickel-plated brass with stainless pin and spring | turn-button eyelet |

