A4 Stainless Steel Panel Nuts (Thin, Fine Pitch) combine the dimensional form of DIN 439 with the material properties of grade ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80: superior, including marine and chloride environments, 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 A4 Stainless Steel for Panel Nuts (Thin, Fine Pitch)
Specified for marine, coastal and chemical applications. For panel nuts (thin, fine pitch), 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 |
Galvanic & Galling Considerations
Two important notes for stainless panel nuts (thin, fine pitch): (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 Panel Nuts (Thin, Fine Pitch), 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 Panel Nuts (Thin, Fine Pitch) Available in A4 Stainless Steel
| Thread size | Pitch (mm) | Across flats s (mm) | Across corners e (mm) | Nut height m (mm) | Typical application | Reference standard |
|---|---|---|---|---|---|---|
| M6x0.75 | 0.75 | 10 | 11.05 | 3.2 | Potentiometer bushing | DIN 439 B |
| M8x0.75 | 0.75 | 13 | 14.38 | 4.0 | Toggle switch bushing | DIN 439 B |
| M9x0.75 | 0.75 | 14 | 15.51 | 4.0 | Rotary switch bushing | DIN 439 B |
| M10x0.75 | 0.75 | 17 | 18.90 | 5.0 | Indicator lamp | DIN 439 B |
| M12x1 | 1.0 | 19 | 21.10 | 5.0 | Cable gland PG/M12 | DIN 439 B |
| M16x1.5 | 1.5 | 24 | 26.75 | 6.0 | Cable gland M16 | DIN 439 B |
| M20x1.5 | 1.5 | 30 | 33.53 | 8.0 | Cable gland M20 | DIN 439 B |
