Fixing and buying guide
HEX HEAD TIMBERFAST BLACK (BOX 50) 125mm
What you are buying
You are purchasing a box of 50 individual HEX HEAD TIMBERFAST BLACK screws, each 125mm in length. The screws are made from high tensile steel with a hardened hex head and integral 12mm diameter washer. The thread length is 50mm, with 75mm of unthreaded shank. Every box includes one hex driver bit for installation.
- Length: 125mm overall
- Thread length: 50mm
- Hex head with 12mm moulded washer
- Self-drilling point
- Ruspert black coating for corrosion resistance
- High tensile steel construction
- Quantity: 50 screws per box
- Hex driver bit included
Who these screws are for and typical uses
These screws are engineered for trade professionals and serious DIY users undertaking structural and landscaping projects. The 125mm length and robust hex head make them ideal for fixing timber to timber in applications where strength and durability are critical. Common uses include decking installation, fence post assembly, landscaping structures, and general structural joinery where corrosion resistance is required.
- Structural timber-to-timber fixings
- Exterior decking and boardwalks
- Fence and gate construction
- Landscaping timber projects
- Coastal and salt-spray environments
Compatibility and sizing
The 125mm length is suitable for fixing timber sections where the combined thickness of materials being joined is approximately 75mm or less, accounting for the 50mm thread engagement required for secure holding. The self-drilling point works effectively in softwoods and some hardwoods without pilot holes, though hardwoods or dense timbers may benefit from pre-drilling. The hex head and washer design are compatible with standard hex driver bits, and the included bit is supplied for immediate use.
- Suitable for timber thicknesses up to approximately 75mm combined
- Self-drilling in softwoods; consider pilot holes for hardwoods
- Hex driver bit supplied in box
- Ruspert coating suitable for exterior and coastal exposure
Before you install
Check that your timber is dry and free from rot or significant defects. Ensure the hex driver bit is properly seated in the screw head before driving to avoid stripping. For hardwoods or timbers over 50mm thickness, consider drilling a pilot hole slightly smaller than the screw core diameter to reduce driving effort and risk of timber splitting. The self-drilling point is designed to minimise pilot hole requirements in standard softwoods, but pre-drilling is always an option if preferred. Verify that the combined thickness of materials being joined does not exceed the effective penetration depth of the 50mm thread.
- Inspect timber for moisture, rot and defects
- Ensure hex driver bit is fully seated before driving
- Consider pilot holes in hardwoods or dense timbers
- Verify material thickness allows adequate thread engagement
- Use appropriate power tool speed to avoid overdriving