A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is specified for marine, coastal and chemical applications. Specified on rivet nuts (blind threaded inserts) it determines the corrosion behaviour (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); the dimensions are ours rather than a standard's, and are listed in full below.
Why Choose A4 Stainless Steel for Rivet Nuts (Blind Threaded Inserts)
Specified for marine, coastal and chemical applications. For rivet nuts (blind threaded inserts), 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 Rivet Nuts (Blind Threaded Inserts) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless rivet nuts (blind threaded inserts): (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.
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 Rivet Nuts (Blind Threaded Inserts) Available in A4 Stainless Steel
| Thread size | Body diameter (mm) | Body length (mm) | Grip range (mm) | Hole diameter (mm) | Head diameter (mm) | Body form | Material |
|---|---|---|---|---|---|---|---|
| M3 | 5.0 | 9.5 | 0.5~1.5 | 5.0 | 7.0 | Round, open end | Steel zinc / A2 |
| M4 | 6.0 | 11.5 | 0.5~2.0 | 6.0 | 9.0 | Round, open end | Steel zinc / A2 |
| M5 | 7.0 | 12.5 | 0.5~3.0 | 7.0 | 10.0 | Round, open end | Steel zinc / A2 |
| M6 | 9.0 | 15.5 | 0.5~3.0 | 9.0 | 13.0 | Round, open end | Steel zinc / A2 |
| M8 | 11.0 | 17.0 | 0.5~3.5 | 11.0 | 16.0 | Round, open end | Steel zinc |
| M10 | 13.0 | 19.0 | 1.0~4.0 | 13.0 | 18.0 | Round, open end | Steel zinc |
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.
