Material specification page for self-locking counter nuts 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 DIN 7967.
Why Choose A2 Stainless Steel for Self-Locking Counter Nuts
The most common stainless group for indoor and general outdoor fasteners. For self-locking counter nuts, 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 Self-Locking Counter Nuts 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 Self-Locking Counter Nuts, 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 Self-Locking Counter Nuts Available in A2 Stainless Steel
| Size | od (mm) | id (mm) | Nut height m (mm) | Width across flats s (mm) | t (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M4 | 4 | 3.5 | 2.5 | 7 | 0.3 | DIN 7967 |
| M5 | 5 | 4.5 | 2.5 | 8 | 0.4 | DIN 7967 |
| M6 | 6 | 5.3 | 3 | 10 | 0.4 | DIN 7967 |
| M8 | 8 | 6.9 | 3.5 | 13 | 0.5 | DIN 7967 |
| M10 | 10 | 8.6 | 4 | 17 | 0.5 | DIN 7967 |
| M12 | 12 | 10.4 | 4.5 | 19 | 0.6 | DIN 7967 |
| M14 | 14 | 12 | 5 | 22 | 0.6 | DIN 7967 |
| M16 | 16 | 14.1 | 5 | 24 | 0.7 | DIN 7967 |
| M18 | 18 | 15.5 | 5.5 | 27 | 0.7 | DIN 7967 |
| M20 | 20 | 17.6 | 6 | 30 | 0.8 | DIN 7967 |
| M22 | 22 | 19.6 | 6 | 32 | 0.8 | DIN 7967 |
| M24 | 24 | 21 | 7 | 36 | 0.9 | DIN 7967 |
| M27 | 27 | 24.2 | 7 | 41 | 1 | DIN 7967 |
| M30 | 30 | 26.6 | 8 | 46 | 1.1 | DIN 7967 |
| M33 | 33 | 29.8 | 8 | 50 | 1.2 | DIN 7967 |
| M36 | 36 | 32.2 | 9 | 55 | 1.3 | DIN 7967 |
| M39 | 39 | 35.2 | 9 | 60 | 1.3 | DIN 7967 |
| M42 | 42 | 37.6 | 11 | 65 | 1.4 | DIN 7967 |
| M45 | 45 | 40.9 | 12 | 70 | 1.5 | DIN 7967 |
| M48 | 48 | 43.9 | 14 | 75 | 1.6 | DIN 7967 |
| M52 | 52 | 48.2 | 16 | 80 | 1.7 | DIN 7967 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this nut in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Locking method is specifiable independently of the rest: nylon insert, all-metal deformed thread, serrated flange, or none. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
