M6 M8 M10 Galvanised Countersunk Head Sleeve Anchor Expansion Bolts

Generally, the anchor embedment depth should be at least 10× the bolt diameter. For M6, aim for at least 60mm (≈2-3/8") embedment; for M8, at least 80mm (≈3-1/8"); for M10, at least 100mm (≈3-15/16"). Add the fixture thickness to determine total bolt length needed. For example, fixing a 10mm steel plate with an M8 anchor requires a bolt of at least 90mm total length. When in doubt, choose the next size up.

Actual load capacity depends on the base material strength, embedment depth, and edge/spacing distances. In standard concrete (C20/25), M6 sleeve anchors typically handle 1–2 kN tensile load, M8 anchors generally 2–3 kN, and M10 anchors generally 3–5 kN. These figures are indicative only — always consult a structural engineer and refer to certified load tables for safety-critical or overhead applications.

The zinc galvanised coating provides good corrosion resistance for general outdoor use in covered or sheltered locations — garages, covered walkways, industrial sheds. They are suitable for occasional moisture exposure. For permanently wet, submerged, or coastal/marine environments where salt spray is present, stainless steel sleeve anchors are generally the more appropriate choice.

These anchors use standard ISO metric coarse threads: M6, M8, and M10. They are fully compatible with standard metric nuts, washers, and bolts of the same designation. They are not compatible with UNC or UNF inch-standard fasteners. If you are working on an older imperial-spec structure, verify your existing hardware before ordering.

Use a carbide-tipped masonry or SDS hammer drill bit matching the anchor's outer sleeve diameter — typically 10mm for M6, 12mm for M8, and 14mm for M10 anchors. Always verify against the sleeve OD printed on the packaging. Drill the hole to the correct depth (embedment depth + 5–10mm clearance), blow out dust, and insert the anchor before tightening.

These sleeve anchors are designed for solid concrete, dense brick, and hard masonry where the hole wall is firm enough to resist the outward expansion force. They are generally not recommended for hollow block, aerated concrete (AAC/Hebel), soft or crumbling masonry, or thin-section materials without additional engineering assessment. If you are unsure about your substrate, contact us before ordering.

Sleeve anchors are in most cases a one-time-use fastener. Once the sleeve has expanded against the hole wall, it deforms permanently. The bolt can be removed and the hole re-used for a new anchor of the same or larger size, but reinstalling a new bolt into the original expanded sleeve is not recommended for any load-bearing application.