A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is specified for marine, coastal and chemical applications. Specified on elevator bolts 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 Elevator Bolts
Specified for marine, coastal and chemical applications. For elevator bolts, 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 Elevator Bolts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless elevator bolts: (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
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 Elevator Bolts Available in A4 Stainless Steel
| Thread size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Square neck width (mm) | Neck depth (mm) | Common length range (mm) | Typical finish |
|---|---|---|---|---|---|---|---|
| M6 | 1.0 | 19.0 | 2.4 | 6.4 | 5.0 | 16~60 | Zinc plated / A2 |
| M8 | 1.25 | 25.0 | 3.0 | 8.4 | 6.0 | 20~80 | Zinc plated / A2 |
| M10 | 1.5 | 32.0 | 3.5 | 10.5 | 7.0 | 25~100 | Zinc plated / A2 |
| M12 | 1.75 | 38.0 | 4.0 | 12.5 | 8.0 | 30~120 | Zinc plated / A2 |
| M16 | 2.0 | 50.0 | 5.0 | 16.5 | 9.0 | 40~150 | Zinc plated |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this bolt in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
