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 coiled spring pins, heavy duty are specified in this grade, the dimensions remain per ISO 8748; 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 Coiled Spring Pins, Heavy Duty
The most common stainless group for indoor and general outdoor fasteners. For coiled spring pins, heavy duty, 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 coiled spring pins, heavy duty 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 Coiled Spring Pins, Heavy Duty, 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
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Coiled Spring Pins, Heavy Duty Available in A2 Stainless Steel
| Nominal diameter d (mm) | d_1 (mm) | d_2 (mm) | a (mm) | s (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|
| 1.5 mm | 1.66 | 1.4 | 0.5 | 0.17 | 4~26 | ISO 8748 |
| 2 mm | 2.16 | 1.9 | 0.7 | 0.22 | 4~40 | ISO 8748 |
| 2.5 mm | 2.675 | 2.4 | 0.7 | 0.28 | 5~45 | ISO 8748 |
| 3 mm | 3.185 | 2.9 | 0.9 | 0.33 | 6~50 | ISO 8748 |
| 3.5 mm | 3.715 | 3.4 | 1 | 0.39 | 6~50 | ISO 8748 |
| 4 mm | 4.225 | 3.9 | 1.1 | 0.45 | 8~60 | ISO 8748 |
| 5 mm | 5.25 | 4.85 | 1.3 | 0.56 | 10~60 | ISO 8748 |
| 6 mm | 6.29 | 5.85 | 1.5 | 0.67 | 12~75 | ISO 8748 |
| 8 mm | 8.4 | 7.8 | 2 | 0.9 | 16~120 | ISO 8748 |
| 10 mm | 10.475 | 9.75 | 2.5 | 1.1 | 20~120 | ISO 8748 |
| 12 mm | 12.55 | 11.7 | 3 | 1.3 | 24~160 | ISO 8748 |
| 14 mm | 14.625 | 13.6 | 3.5 | 1.6 | 28~200 | ISO 8748 |
| 16 mm | 16.65 | 15.6 | 4 | 1.8 | 35~200 | ISO 8748 |
| 20 mm | 20.7 | 19.6 | 4.5 | 2.2 | 45~200 | ISO 8748 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this pin in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Tolerance class is what a special pin usually turns on — a locating pin and a retaining pin want very different fits in the same nominal size. Made by cold heading or turning.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
