A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70) is the most common stainless group for indoor and general outdoor fasteners. When fabric snap fasteners are specified in this grade, the dimensions remain per Trade series (fabric snap fasteners); the material determines corrosion behavior (good general corrosion resistance) and the service temperature range (approx. -200 °C to +400 °C, subject to the property class and the joint). Both are covered below with the size table.
Why Choose A2 Stainless Steel for Fabric Snap Fasteners
The most common stainless group for indoor and general outdoor fasteners. For fabric snap fasteners, 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 |
Galvanic & Galling Considerations
For stainless fabric snap fasteners 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.
Comparable Grades
For Fabric Snap Fasteners, the alternative stainless grade is A4 (316). A2 (304) covers general indoor and outdoor service. A4 (316) adds molybdenum, which is what buys the chloride resistance for marine and de-icing-salt exposure. Where strength matters more than corrosion, plated alloy steel in class 8.8 or 10.9 is the swap to make.
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 Fabric Snap Fasteners Available in A2 Stainless Steel
| Snap diameter (in) | Stud form | Stud thread / screw | Stud length (in) | Material options | Fabric / panel selection |
|---|---|---|---|---|---|
| 1/2 | threaded stud | 8-32 | 3/16 or 1/2 | 18-8 stainless / black- or nickel-plated brass or steel | match the mating fabric hardware |
| 9/16 | tapping-screw stud | No. 7 | 3/8 | 18-8 stainless / black- or nickel-plated brass or steel | match the mating fabric hardware |
| 9/16 | blind-rivet stud | 18-8 stainless / black- or nickel-plated brass or steel | 0.125~0.188 or 0.188~0.375 in; 0.125 in hole |
