A2 Stainless Steel Retaining Rings (Circlips) combine the dimensional form of DIN 471 / DIN 472 with the material properties of grade ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70: good general corrosion resistance, largely non-magnetic, service range approx. -200 °C to +400 °C, subject to the property class and the joint. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose A2 Stainless Steel for Retaining Rings (Circlips)
The most common stainless group for indoor and general outdoor fasteners. For retaining rings (circlips), 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 retaining rings (circlips) 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 Retaining Rings (Circlips), 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 Retaining Rings (Circlips) Available in A2 Stainless Steel
| Nominal shaft / bore diameter (mm) | Ring free diameter (mm) | Groove diameter (mm) | Ring thickness s (mm) | Groove width m min (mm) | Type / standard |
|---|---|---|---|---|---|
| 3 | 2.7 | per DIN 471 - confirm for this size | 0.4 | per DIN 471 - confirm for this size | DIN 471 external |
| 4 | 3.7 | per DIN 471 - confirm for this size | 0.4 | per DIN 471 - confirm for this size | DIN 471 external |
| 5 | 4.7 | per DIN 471 - confirm for this size | 0.6 | per DIN 471 - confirm for this size | DIN 471 external |
| 6 | 5.6 | per DIN 471 - confirm for this size | 0.7 | per DIN 471 - confirm for this size | DIN 471 external |
| 7 | 6.5 | per DIN 471 - confirm for this size | 0.8 | per DIN 471 - confirm for this size | DIN 471 external |
| 8 | 7.4 | per DIN 471 - confirm for this size | 0.8 | per DIN 471 - confirm for this size | DIN 471 external |
| 9 | 8.4 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 10 | 9.3 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 11 | 10.2 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 12 | 11.1 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 14 | 13.0 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 15 | 14.0 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 16 | 15.0 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 17 | 16.0 | per DIN 471 - confirm for this size | 1.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 18 | 17.0 | per DIN 471 - confirm for this size | 1.2 | per DIN 471 - confirm for this size | DIN 471 external |
| 19 | 18.0 | per DIN 471 - confirm for this size | 1.2 | per DIN 471 - confirm for this size | DIN 471 external |
| 20 | 19.0 | per DIN 471 - confirm for this size | 1.2 | per DIN 471 - confirm for this size | DIN 471 external |
| 22 | 21.0 | per DIN 471 - confirm for this size | 1.2 | per DIN 471 - confirm for this size | DIN 471 external |
| 24 | 22.9 | per DIN 471 - confirm for this size | 1.2 | per DIN 471 - confirm for this size | DIN 471 external |
| 25 | 23.9 | per DIN 471 - confirm for this size | 1.2 | per DIN 471 - confirm for this size | DIN 471 external |
| 28 | 26.9 | per DIN 471 - confirm for this size | 1.5 | per DIN 471 - confirm for this size | DIN 471 external |
| 30 | 28.9 | per DIN 471 - confirm for this size | 1.5 | per DIN 471 - confirm for this size | DIN 471 external |
| 32 | 30.9 | per DIN 471 - confirm for this size | 1.5 | per DIN 471 - confirm for this size | DIN 471 external |
| 35 | 33.8 | per DIN 471 - confirm for this size | 1.5 | per DIN 471 - confirm for this size | DIN 471 external |
| 40 | 38.5 | per DIN 471 - confirm for this size | 1.75 | per DIN 471 - confirm for this size | DIN 471 external |
| 45 | 43.5 | per DIN 471 - confirm for this size | 1.75 | per DIN 471 - confirm for this size | DIN 471 external |
| 50 | 48.5 | per DIN 471 - confirm for this size | 2.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 55 | 53.3 | per DIN 471 - confirm for this size | 2.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 60 | 58.3 | per DIN 471 - confirm for this size | 2.0 | per DIN 471 - confirm for this size | DIN 471 external |
| 65 | 63.3 | per DIN 471 - confirm for this size | 2.5 | per DIN 471 - confirm for this size | DIN 471 external |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this retaining ring in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Temper and thickness set the thrust the ring will take, and both are specifiable against the load rather than picked from a table. Made by stamping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.


