A2 Stainless Steel Castle Nuts (DIN 935) combine the dimensional form of DIN 935 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 Castle Nuts (DIN 935)
The most common stainless group for indoor and general outdoor fasteners. For castle nuts (din 935), 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
Two important notes for stainless castle nuts (din 935): (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Comparable Grades
For Castle Nuts (DIN 935), the alternative stainless grade is A4 (316). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
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 Castle Nuts (DIN 935) Available in A2 Stainless Steel
| Thread size | Pitch (mm) | Width across flats s (mm) | Total height m (mm) | Slot width n (mm) | Slot depth (mm) | Split pin size | Reference standard |
|---|---|---|---|---|---|---|---|
| M8 | 1.25 | 13.0 | 9.5 | 2.5 | 3.5 | 2 x 25 | DIN 935 |
| M10 | 1.5 | 17.0 | 11.5 | 2.8 | 4.0 | 2.5 x 30 | DIN 935 |
| M12 | 1.75 | 19.0 | 14.0 | 3.5 | 5.5 | 3.2 x 36 | DIN 935 |
| M16 | 2.0 | 24.0 | 17.0 | 4.5 | 6.0 | 4 x 40 | DIN 935 |
| M20 | 2.5 | 30.0 | 20.0 | 4.5 | 6.0 | 4 x 50 | DIN 935 |
| M24 | 3.0 | 36.0 | 24.0 | 5.5 | 8.0 | 5 x 63 | DIN 935 |
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. Thread, height, across-flats, property class, locking feature and flange form can all be varied, including thread sizes the standard series does not run to. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
