Masonry Concrete Expansion Bolts – Socket Cap Head, A2 Stainless Steel (M6–M12)

Generally, the bolt should penetrate the base material (concrete or masonry) by at least 5–10 times the bolt diameter. For example, an M8 bolt typically requires at least 40–80mm (≈1.6–3.1") of embedment depth. Measure your fixture thickness first, then add the required embedment depth to determine total bolt length. For example, a 10mm bracket with an M8 bolt would typically need a 50–90mm bolt (≈2–3.5").

Load capacity depends on bolt size, embedment depth, and the base material strength. In most cases, M6 bolts in solid concrete are suited for lighter loads (shelving, conduit), while M10–M12 bolts handle heavier structural fixtures. Always consult a structural engineer for load-critical applications and refer to pull-out test data for your specific substrate.

Yes. These bolts are made from A2 (304) stainless steel, which provides good corrosion resistance in most outdoor and mildly corrosive environments. They are generally suitable for exterior masonry, garden walls, and covered outdoor structures. For highly aggressive environments (coastal, chemical exposure), A4 (316) stainless steel is typically recommended instead.

These bolts use standard ISO metric coarse threads (M6, M8, M10, M12), compatible with standard metric nuts, washers, and threaded inserts following DIN/ISO specifications. Always verify thread pitch compatibility before pairing with existing hardware.

Use a carbide-tipped masonry drill bit matching the bolt's nominal diameter — for example, an M8 expansion bolt generally requires an 8mm masonry bit. Drill depth should exceed the bolt's embedment length by approximately 5–10mm to allow for dust clearance. Always use a hammer drill for concrete and hard masonry.

Expansion bolts are designed for solid substrates such as poured concrete, solid brick, and dense stone. In most cases, they are not recommended for hollow block, aerated concrete (AAC), or soft brick, as the expansion mechanism requires solid material to grip. For hollow substrates, consider a sleeve anchor or chemical anchor instead.

Socket cap head bolts require a hex (Allen) key or hex socket driver. The key size varies by bolt diameter — typically 5mm for M6, 6mm for M8, 8mm for M10, and 10mm for M12. Always torque to the recommended specification to avoid over-expansion or substrate cracking.