Timber-Tite TFNPHX65145 Hex Bolt Self Drilling Heavy Duty Landscape Screws 6.5mm x 145mm 50 Pack

Partially threaded outdoor screws for all heavy duty applications including joists, framing and sleepers. 8mm hex works with nut spinner or socket to apply extra torque, whilst flange washer protects surface.
Strong as an HT bolt, the screw should not snap, and with no need to pilot in most materials.
Exaggerated part thread prevents jacking and provides exceptional clamping.
Net-Coat protection, designed to withstand the elements and works against chemicals to combat galvanic corrosion.