This SPAX step drill is specifically designed to be used with the SPAX 5mm decking screws. It will pre-drill your hole at the correct diameter and countersink the timber at the correct diameter for the SPAX decking head. It ensures a perfect finish every time.
This step drill includes a bit to suit soft wood joists and a bit to suit hardwood joists. Bits are easily interchanged by loosening the grub screw.