M6–M12 Countersunk Expansion Bolts | 201 Stainless Steel Hex Socket Sleeve Anchors

A general rule is to select a bolt length that allows at least 25–30mm (about 1") of embedment into the base material beyond the fixture thickness. For example, if you're fastening a 20mm bracket into concrete, an M8 x 60mm bolt typically provides adequate holding depth. When in doubt, go longer — you can always use a washer to compensate for any gap.

Load capacity depends on the bolt diameter, embedment depth, and base material strength. Generally, M6 bolts in solid concrete are rated for several hundred pounds of shear load, while M12 bolts can handle significantly more. For structural or safety-critical applications, always consult an engineer and refer to pull-out test data for your specific substrate.

Yes. These bolts are made from 201 stainless steel, which provides good corrosion resistance for most outdoor and humid environments. For highly corrosive settings — such as coastal areas or chemical exposure — 316 stainless steel is generally recommended. Contact us to confirm suitability for your specific environment.

These are metric fasteners following ISO/DIN standards. The M6, M8, M10, and M12 designations refer to the nominal thread diameter in millimeters. They are not compatible with UNC or UNF imperial threads. Ensure your nuts and tapped holes are metric before ordering.

These countersunk expansion bolts feature a hex socket (Allen key) drive. You'll typically need a 4mm hex key for M6, 5mm for M8, 6mm for M10, and 8mm for M12 — though this can vary slightly by manufacturer. A hammer drill with a carbide-tipped masonry bit is required to pre-drill the anchor hole in concrete or masonry.

Expansion bolts are generally designed for solid substrates such as poured concrete, solid brick, or natural stone. In hollow block or lightweight aerated concrete, the expansion mechanism may not achieve full grip. For hollow materials, a chemical anchor or toggle bolt is typically a better choice. Contact us if you need guidance on substrate compatibility.

We offer flexible quantity options from 1 piece up to 100 pieces per order, so you can match exactly what your project requires without overstocking. For larger commercial or construction projects, select the higher quantity tiers for better per-unit value.