Heavy duty 46 grit silicon carbide. For sharpening tungsten carbide-tipped (TCT) tools. Suitable for use on ferrous metals and alloys. 31.75mm (1-1/4″) bore with 12.7mm (1/2″), 15.88mm (5/8″), 19.05mm (3/4″) and 25.4mm (1″) reducing bushes. For use with all 150mm bench grinders. Heavy duty 46 grit silicon carbide. For sharpening tungsten carbide-tipped (TCT) tools. Suitable for use on ferrous metals and alloys. 31.75mm (1-1/4″) bore with 12.7mm (1/2″), 15.88mm (5/8″), 19.05mm (3/4″) and 25.4mm (1″) reducing bushes. For use with all 150mm bench grinders.