Material specification page for t-slot 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 508.
Why Choose A4 Stainless Steel for T-Slot Nuts
Specified for marine, coastal and chemical applications. For t-slot 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 T-Slot Nuts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For T-Slot Nuts, the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.
Using Stainless Fasteners in Aluminum
Stainless steel is more noble than aluminum, so in the presence of an electrolyte — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. The effect is driven by the area ratio: a small stainless fastener in a large aluminum section is normally acceptable, while a large stainless fastener in thin aluminum is not. Where the joint is wet, isolate the two metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of T-Slot Nuts Available in A4 Stainless Steel
| Size | T-slot width a (mm) | Nut width b (mm) | Total height h (mm) | Neck height k (mm) | Chamfer f (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M4 | 5 | 9 | 6.5 | 3 | 1 | DIN 508 |
| M5 | 6 | 10 | 8 | 4 | 1.6 | DIN 508 |
| M6 | 8 | 13 | 10 | 6 | 1.6 | DIN 508 |
| M8 | 10 | 15 | 12 | 6 | 1.6 | DIN 508 |
| M10 | 12 | 18 | 14 | 7 | 2.5 | DIN 508 |
| M12 | 14 | 22 | 16 | 8 | 2.5 | DIN 508 |
| M16 | 18 | 28 | 20 | 10 | 2.5 | DIN 508 |
| M20 | 22 | 35 | 28 | 14 | 2.5 | DIN 508 |
| M24 | 28 | 44 | 36 | 18 | 4 | DIN 508 |
| M30 | 36 | 54 | 44 | 22 | 6 | DIN 508 |
| M36 | 42 | 65 | 52 | 26 | 6 | DIN 508 |
| M42 | 48 | 75 | 60 | 30 | 6 | DIN 508 |
| M48 | 54 | 85 | 70 | 34 | 6 | DIN 508 |
