Corrosion-resistant coating for outdoor use. Double-Countersunk Head with Underhead Ribs 40° Thread for Secure Fixing & High Pull-Out Resistance Zinc-Plated Carbon Steel Construction Ruspert Coated Fully Threaded For Wood, Plastic, Masonry & 1mm Sheet...

Acute tri-lock threadform and shank. Enhanced dual-start with opposing thread gives an easy straight drive. Stick-tite recess for maximum grip between bit and screw. Dowel ream reduces timber splitting. Zinc and yellow-passivated. Double Self-Countersunk...