Hex Timber Screws – A4 Stainless Steel

A4 Stainless Steel Hex Timber Screws are designed as a high-performance alternative to traditional coach screws, offering exceptional corrosion resistance for timber-to-timber applications in demanding outdoor environments.

Manufactured from solid A4 grade stainless steel, these screws are suitable for coastal locations, high-moisture areas and tannin-rich timbers such as Green Oak. Where standard coated exterior screws may corrode over time, A4 stainless screws provide long-term durability and structural reliability.

The hex head with integrated fixed washer delivers strong clamping force and controlled high-torque installation. A 50° deep single thread ensures secure pull-out resistance, while the helix shank clears debris during driving to improve clamping efficiency. A sharp 25° point and single slash tip help reduce splitting, even when fixing close to edges.

In most softwoods, a pilot hole is not required. However, for dense hardwoods or structural oak applications, a pilot hole is recommended.

What is A4 Stainless Steel?

A4 stainless steel (also known as marine grade stainless steel) contains molybdenum, which significantly improves corrosion resistance compared to A2 stainless steel. This makes it particularly suitable for:

• Coastal environments
• High humidity conditions
• External structural timber
• Green Oak and hardwood projects

A2 vs A4 Stainless Steel Comparison

Choosing the Right Length

For structural timber fixing, the screw should penetrate deeply into the second timber to ensure long-term holding strength.

As a general guide, aim for 2–3× the thickness of the top timber.