Advanced Material Inserts Grade Numbering System Grade Numbering System — Ceramics CW 2 0 15 Brand Cutting Application Range Material Group CW = WIDIA™ 2 = CM Mixed (black) 0 = Stationary cutting edges 05 = fine finishing ceramic (turning, parting, threading) 10 = finishing 3 = CR Whisker reinforced 1 = First successorceramic5= CNSilicon nitride2=Semi-standard1520==} medium to roughing ceramic rotating cutting edges3=Semi-standard 2530==} roughing general applications5=Rotating cutting edges(milling, drilling, reaming)354045===} heaviest roughing 50 = B164 widia.com