TradeCalculator.co.uk
UK Anchor Bolt & Wall Plug Sizes
Wall plugs, rawlbolts, sleeve anchors and chemical anchors with drill hole sizes, load ratings and colour codes for UK fixings.
Standard Wall Plug Sizes (Colour Coded)
| Colour | Drill Size (mm) | Screw Gauge | Screw Size (mm) | Typical Use |
|---|---|---|---|---|
| Yellow | 5 | No.4–8 | 3.0–4.0 | Light shelves, pictures, switch plates |
| Red | 5.5 | No.6–10 | 3.5–5.0 | Curtain poles, brackets, towel rails |
| Brown | 7 | No.8–14 | 4.0–6.0 | Heavy shelving, TV brackets, radiators |
| Blue | 10 | No.14–18 | 6.0–8.0 | Heavy-duty, boilers, large brackets |
Rawlbolts (Expanding Anchors)
Mechanical expanding anchors for solid masonry and concrete. The bolt tightens a cone which expands a shield against the hole walls.
| Bolt Size | Drill Hole (mm) | Min. Hole Depth (mm) | Safe Load — Concrete (kg) |
|---|---|---|---|
| M6 | 10 | 45 | ~120 |
| M8 | 12 | 55 | ~200 |
| M10 | 14 | 65 | ~340 |
| M12 | 16 | 75 | ~520 |
| M16 | 22 | 95 | ~900 |
Safe loads are indicative for C20/25 concrete. Always check manufacturer data for your specific substrate.
Sleeve Anchors
Suitable for solid and hollow masonry. The sleeve expands along its full length for better load distribution in weaker substrates.
| Bolt Size | Drill Hole (mm) | Lengths Available (mm) | Typical Use |
|---|---|---|---|
| M6 | 8 | 40–100 | Light steelwork, cable trays |
| M8 | 10 | 50–130 | Racking, handrails, brackets |
| M10 | 12 | 60–160 | Steelwork, joist hangers, gates |
| M12 | 14 | 75–200 | Heavy structural connections |
Chemical (Resin) Anchors
Two-part resin injected into a drilled hole with a threaded stud. Ideal for hollow blocks, aerated concrete and close-to-edge fixings.
| Stud Size | Drill Hole (mm) | Embedment (mm) | Resin Type |
|---|---|---|---|
| M8 | 10 | 80 | Polyester / vinylester / epoxy |
| M10 | 12 | 90 | Polyester / vinylester / epoxy |
| M12 | 14 | 110 | Polyester / vinylester / epoxy |
| M16 | 18 | 125 | Vinylester / epoxy (structural) |
Use perforated sleeves (mesh sleeves) when fixing into hollow blocks with chemical anchors. Cure times vary by temperature — typically 20-45 minutes at 20°C.
Related Calculators
See the Fixings Guide by Wall Type for choosing fixings by substrate, or the UK Screw Sizes reference for screw gauges.
Frequently Asked Questions
Related Calculators
Related Calculators
UK Cavity Tray Sizes
Cavity tray DPC types, widths, weep hole spacing and material specifications for UK cavity wall construction.
UK Cable Sizes
BS 7671 cable sizes and current ratings for common UK domestic circuits and installations.
UK Screw and Fixing Sizes
UK screw gauge sizes, lengths and pilot hole diameters for wood, masonry and metal fixings.
BS 7671 Domestic Circuit Guide
BS 7671 domestic circuit specifications: cable sizes, MCB ratings and protective devices.
Was this calculator helpful?
Last updated: April 2026
Verified against UK standards · estimates only, confirm with your supplier.