3M(TM) CBN Polyimide Bond Cup Wheel 11V9, 5 in x 1-3/4 in x 1-1/4 in, X=1/8, CB220 P100 BP, 1 per case CBN particles in a polyimide bond matrix offer high cut rates, excellent abrasive life and temperature resistance in cup wheels in cnc grinding applications, of hardened steels and superalloys.