A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is specified for marine, coastal and chemical applications. When self-clinching standoffs for sheet metal are specified in this grade, the dimensions remain per Trade series (self-clinching sheet-metal standoffs); the material determines corrosion behavior (superior, including marine and chloride environments) and the service temperature range (approx. -200 °C to +400 °C, subject to the property class and the joint). Both are covered below with the size table.
Why Choose A4 Stainless Steel for Self-Clinching Standoffs for Sheet Metal
Specified for marine, coastal and chemical applications. For self-clinching standoffs for sheet metal, 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 self-clinching standoffs for sheet metal: (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 Self-Clinching Standoffs for Sheet Metal, the alternative stainless grade is A2 (304). 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
Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of Self-Clinching Standoffs for Sheet Metal Available in A4 Stainless Steel
| Thread size | Length options (mm) | Form options | Material options | Installation |
|---|---|---|---|---|
| M2.5 | 2 / 3 / 4 / 6 / 8 / 10 / 12 / 14 / 16 / 18 / 19 | through / partial / blind | steel / stainless / aluminum / hardened stainless | self-clinching in sheet metal |
| M3 | 2 / 3 / 4 / 6 / 8 / 10 / 12 / 14 / 16 / 18 / 19 | through / partial / blind | steel / stainless / aluminum / hardened stainless | self-clinching in sheet metal |
| M3.5 | 2 / 3 / 4 / 6 / 8 / 10 / 12 / 14 / 16 / 18 / 19 | through / partial / blind | steel / stainless / aluminum / hardened stainless | self-clinching in sheet metal |
