The Faithfull High Speed Steel Rosehead 90° included angle countersink. For countersinking screw holes for flush fitting of screw heads in mild steel, plastics and non-ferrous metals. Also suitable for working in wood, plywood, MDF and other man made boards. Can be used in both hand tools and power drills. Type: Rosehead Size: 13mm (1/2in) Length: 40mm (1.5/8in) Shank diam: 6mm (1/4in) FAICS12HS