M6 Countersunk Sleeve Anchor Expansion Bolts — 304 / 201 Stainless Steel, Cross Drive

A general rule: the anchor length should be at least 3–4 times the bolt diameter plus the thickness of the material being fastened. For M6 anchors, add your fixture thickness to the minimum embedment depth (typically 25–35mm) to determine the total length needed. Available lengths run from 52mm (≈2.0") to 182mm (≈7.2"). For example, fastening a 20mm bracket to concrete with 40mm embedment requires at least a 60mm anchor — the 72mm option would be appropriate.

Load capacity depends on the base material (concrete grade, brick, or block), embedment depth, and edge/spacing distances. For M6 sleeve anchors in standard concrete, tensile loads are typically in the range of 3–8 kN. Shear capacity is generally higher. Always consult a structural engineer for load-critical applications, and contact us to confirm specifications for your specific use case.

Yes. 304 stainless steel offers good corrosion resistance for most outdoor, humid, and mildly corrosive environments — including exterior facades, garden walls, and covered outdoor structures. For coastal, marine, or highly chloride-rich environments, 316 stainless steel is generally recommended. 201 stainless steel is best suited for indoor or low-humidity conditions.

These anchors use M6 metric coarse thread — the international standard used across most European and Asian-manufactured hardware. They are compatible with standard M6 metric nuts, washers, and threaded fixtures. They are not designed for UNC or UNF inch-standard threads. If your fixture uses imperial threads, an adapter or different anchor type would be needed.

304 stainless steel contains a higher nickel content (typically 8–10%), giving it superior corrosion resistance and longer service life in outdoor or damp conditions. 201 stainless steel uses manganese in place of some nickel, making it a more economical option that still outperforms carbon steel in corrosion resistance — but is generally recommended for indoor or low-humidity applications only.

These countersunk sleeve anchors are generally suitable for solid concrete, dense brick, and natural stone. They are not recommended for hollow block, aerated concrete (AAC), drywall, or soft masonry without additional engineering review. The expansion mechanism requires a solid, non-crumbling hole wall to develop full holding strength.

For M6 sleeve anchors with a 10mm body diameter, you typically need a 10mm carbide-tipped masonry or hammer drill bit. Use a rotary hammer drill for concrete and brick for best results. Drill to the depth specified on the anchor or at least equal to the anchor length. Clean the hole of dust before inserting the anchor.

1. Drill a 10mm hole to the required depth using a masonry bit. 2. Clear dust from the hole with a brush or compressed air. 3. Insert the sleeve anchor through your fixture and into the hole. 4. Use a Phillips or cross-head driver to tighten the bolt — the sleeve expands as you turn. 5. Tighten until the head sits flush with the fixture surface. Do not overtighten, as this can crack the base material around the hole.