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M8 lag / coach screw size
13 mm wrench
wrench size for M8 coach screw
M8 coach screw — Wood construction, timber framing, decking.
Full specification
| System | Metric coarse |
| Nominal diameter | 8 mm |
| Thread pitch | 1.25 mm |
| Wrench size | 13 mm |
| Pilot drill (wood) | 6.0 mm |
| Clearance hole | 9 mm |
| Common grade / class | 4.6 |
| Typical torque | 18 Nm (13.3 ft·lb) |
About M8 coach screws
Wood construction, timber framing, decking.
Coach screws (also called lag screws) have a hexagonal head and wood screw thread. They are designed for heavy-duty applications in wood, including timber framing, decking, and structural wood connections.
Always drill a pilot hole to prevent splitting. The pilot hole should be slightly smaller than the core diameter of the screw.
Frequently asked questions
- What size wrench fits M8 coach screw?
- M8 coach screw uses a 13 mm wrench.
- What is the torque for M8 coach screw?
- Typical torque for M8 coach screw is about 18 Nm (13.3 ft·lb).
- What are coach screws used for?
- M8 coach screws are used in wood construction, timber framing, decking.