Hex Nut Expansion Sleeve Anchor Bolts — M6 to M20, Galvanized & Stainless Steel

Match the bolt diameter to your fixture's hole size — for example, M8 (≈5/16" diameter) for medium-duty brackets. For length, a general rule is: bolt length = fixture thickness + minimum embedment depth (typically 4–5x the bolt diameter). For instance, an M8 bolt anchoring a 10mm bracket into concrete typically needs at least 40–50mm embedment, so choose M8 x 60mm or longer. When in doubt, go one size longer.

Load capacity depends on bolt diameter, embedment depth, and base material strength. Generally, M6 anchors handle lighter loads in solid concrete, while M16–M20 anchors are suited for structural applications. Always consult a structural engineer for safety-critical installations.

Yes, with the right material choice. Galvanized steel offers good corrosion resistance for general outdoor use. 304 stainless steel is suitable for most outdoor and mildly corrosive environments. 316 stainless steel provides the highest corrosion resistance and is recommended for coastal, marine, or chemically exposed environments.

These bolts use standard metric coarse threads (ISO metric thread standard), compatible with standard metric hex nuts and washers. The M designation (M6, M8, M10, etc.) refers to the nominal outer diameter in millimeters — for example, M10 is approximately 3/8" in diameter.

These sleeve-type expansion anchors are generally designed for use in solid concrete, brick, and natural stone. They are not recommended for hollow block, drywall, or soft materials where the expansion mechanism cannot grip properly. For hollow substrates, consider toggle bolts or hollow-wall anchors instead.

Choose galvanized steel for indoor or general outdoor applications where cost is a priority. Choose 304 stainless steel for environments with moderate moisture or mild chemical exposure — such as covered outdoor structures or food-service areas. Choose 316 stainless steel for coastal, marine, pool, or industrial environments where maximum corrosion resistance is needed.

Drill a hole matching the bolt diameter and required depth into the base material using a hammer drill and masonry bit. Clean out the hole of dust and debris. Insert the anchor bolt with the sleeve into the hole. Place your fixture over the protruding threaded shank, add a washer, and thread on the hex nut. Tighten the nut with a wrench — as it tightens, the sleeve expands against the hole walls, creating a secure mechanical grip.