Material specification page for hexagon weld nuts in A4 Stainless Steel. Covers the grade designation (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to DIN 929.
Why Choose A4 Stainless Steel for Hexagon Weld Nuts
Specified for marine, coastal and chemical applications. For hexagon weld nuts, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Hexagon Weld Nuts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Hexagon Weld Nuts, the alternative stainless grade is A2 (304). The practical dividing line is chlorides: A2 (304) is fine until salt is involved, and A4 (316) exists for the cases where it is — coastal, marine and road-salt service. Neither reaches the strength of a plated class 8.8 or 10.9 fastener.
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 Hexagon Weld Nuts Available in A4 Stainless Steel
| Size | Pitch (mm) | Width across flats s (mm) | Width across corners e (mm) | Nut height m (mm) | Pilot diameter d2 (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M3 | 0.5 | 7.5 | 8.15 | 3 | 4.5 | DIN 929 |
| M4 | 0.7 | 9 | 9.83 | 3.5 | 6 | DIN 929 |
| M5 | 0.8 | 10 | 10.95 | 4 | 7 | DIN 929 |
| M6 | 1.0 | 11 | 12.02 | 5 | 8 | DIN 929 |
| M8 | 1.25 | 14 | 15.38 | 6.5 | 10.5 | DIN 929 |
| M10 | 1.5 | 17 | 18.74 | 8 | 12.5 | DIN 929 |
| M12 | 1.75 | 19 | 20.91 | 10 | 14.8 | DIN 929 |
| M14 | 2.0 | 22 | 24.27 | 11 | 16.8 | DIN 929 |
| M16 | 2.0 | 24 | 26.51 | 13 | 18.8 | DIN 929 |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this nut in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Thread size is the obvious variable and rarely the interesting one — height for clearance, across-flats for the tool already in the cell, and the locking feature for the vibration actually present. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
