A4 Stainless Steel Self-Undercutting Mechanical Anchors are supplied to our own published dimensions — this is a trade-series article rather than one covered by a dimensional standard, so confirm the figures against the part you are replacing. The grade provides superior, including marine and chloride environments and is largely non-magnetic; the practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A4 Stainless Steel for Self-Undercutting Mechanical Anchors
Specified for marine, coastal and chemical applications. For self-undercutting mechanical anchors, 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-undercutting mechanical anchors: (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-Undercutting Mechanical Anchors, the alternative stainless grade is A2 (304). A2 (304) covers general indoor and outdoor service. A4 (316) adds molybdenum, which is what buys the chloride resistance for marine and de-icing-salt exposure. Where strength matters more than corrosion, plated alloy steel in class 8.8 or 10.9 is the swap to make.
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 Self-Undercutting Mechanical Anchors Available in A4 Stainless Steel
| Anchor size | Available embedment options (mm) | Maximum fixture thickness options (mm) | Finish | Load cases |
|---|---|---|---|---|
| M10 | 100 / 125 / 190 / 250 | 20 / 30 / 40 / 50 / 60 / 100 | electro-zinc plated, minimum 5 µm | static / dynamic / seismic |
| M12 | 100 / 125 / 190 / 250 | 20 / 30 / 40 / 50 / 60 / 100 | electro-zinc plated, minimum 5 µm | static / dynamic / seismic |
| M16 | 100 / 125 / 190 / 250 | 20 / 30 / 40 / 50 / 60 / 100 | electro-zinc plated, minimum 5 µm | static / dynamic / seismic |
| M20 | 100 / 125 / 190 / 250 | 20 / 30 / 40 / 50 / 60 / 100 | electro-zinc plated, minimum 5 µm | static / dynamic / seismic |
Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in A4 Stainless Steel. The catalogue's default material column has been omitted here so it cannot be read as contradicting that.
Custom manufacturing · Made to drawing
Need this anchor & concrete fixing in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Embedment depth, thread size, body length and corrosion protection are the variables; capacity remains a concrete design value, not a property of the anchor alone. Made by hot forging or thread rolling.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
