A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70) is the most common stainless group for indoor and general outdoor fasteners. Specified on foundation bolts, l and j form it determines the corrosion behaviour (good general corrosion resistance) 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 A2 Stainless Steel for Foundation Bolts, L and J Form
The most common stainless group for indoor and general outdoor fasteners. For foundation bolts, l and j form, this matters when good general corrosion resistance is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Good general corrosion resistance |
Corrosion Behavior in Service
A2 (304) gives excellent atmospheric and most-water corrosion resistance and is the most common stainless for Foundation Bolts, L and J Form in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Galvanic & Galling Considerations
Two important notes for stainless foundation bolts, l and j form: (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
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of Foundation Bolts, L and J Form Available in A2 Stainless Steel
| Thread size | Form | Overall length L (mm) | Hook length (mm) | Thread length (mm) | Projection above concrete (mm) | Material | Finish |
|---|---|---|---|---|---|---|---|
| M12 | L | 300 | 50 | 60 | 60 | Class 4.6 / 8.8 steel | Hot-dip galvanised |
| M16 | L | 400 | 65 | 80 | 80 | Class 4.6 / 8.8 steel | Hot-dip galvanised |
| M16 | J | 400 | 80 | 80 | 80 | Class 4.6 / 8.8 steel | Hot-dip galvanised |
| M20 | L | 500 | 80 | 100 | 100 | Class 4.6 / 8.8 steel | Hot-dip galvanised |
| M20 | J | 500 | 100 | 100 | 100 | Class 4.6 / 8.8 steel | Hot-dip galvanised |
| M24 | L | 600 | 100 | 120 | 120 | Class 4.6 / 8.8 steel | Hot-dip galvanised |
| M30 | L | 750 | 120 | 150 | 150 | Class 4.6 steel | Hot-dip galvanised |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this bolt in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Dimensions, material, finish and form are specified from the drawing — a bolt outside the standard range is a variation on existing tooling rather than a new design. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
