Sleeve Anchor Expansion Bolts for Concrete – Galvanised Carbon Steel M6 to M20

A general rule is that the anchor should embed at least 6–10 times its diameter into the base material. For example, an M8 anchor (8mm diameter) typically needs at least 48–80mm of embedment. Add the thickness of the fixture to determine the total bolt length needed. For instance, if your fixture is 20mm (≈3/4") thick and you need 60mm (≈2.4") embedment, choose an M8 x 80mm anchor. When in doubt, go longer — you can always use a washer and nut to take up extra length.

Load capacity depends on the anchor diameter, embedment depth, and the strength of the base material. Generally, M6 anchors in standard concrete can handle tensile loads of approximately 3–5 kN, while M12 anchors can typically support 10–15 kN or more. Always consult a structural engineer for load-bearing applications and refer to the specific anchor's technical data sheet for certified values.

These anchors feature a galvanised zinc coating that provides good corrosion resistance for general outdoor use, including exposure to rain and humidity. They are suitable for most exterior applications such as fencing, pergolas, and outdoor structures. For highly corrosive environments — such as coastal areas, swimming pools, or chemical exposure — stainless steel anchors are generally recommended instead.

These sleeve anchors use standard ISO metric threads (M6, M8, M10, M12, M14, M16, M18, M20), which are compatible with standard metric nuts, washers, and bolts. They are not compatible with UNC/UNF inch-based fasteners. If you are unsure about compatibility with your fixture, contact us to confirm before ordering.

Sleeve anchors are designed for use in solid, hard base materials including poured concrete, concrete block, brick, and natural stone. They are not suitable for hollow block, drywall, wood, or soft masonry without additional engineering review. For best results, the base material should be at least 1.5 times the anchor's minimum embedment depth in thickness.

Yes. You will need a carbide-tipped masonry or hammer drill bit that matches the anchor's nominal diameter. For example, use a 10mm masonry bit for M10 anchors. A rotary hammer drill is strongly recommended for concrete — a standard drill will work in softer masonry but will be much slower. Always drill to the correct depth (typically anchor length + 10–15mm clearance) and clean out the hole before inserting the anchor.

Sleeve anchors are generally considered a permanent fastening solution. Once expanded in the base material, they cannot be fully removed without damaging the surrounding concrete. The bolt portion can be unthreaded and the sleeve left in place, but the hole will need to be repaired if the anchor location needs to change. For applications requiring removable fasteners, consider using drop-in anchors or wedge anchors with removable bolt designs.