1.PDC anchor bits for conglomerate,granite,limestone 2.High abrasion resistance ,high impact resistance,high drilling efficienc ... PDC anchor bits for conglomerate,granite,limestone PDC anchor shank drill bits are mainly used for the ... to rock formation of f below 14,like gravel, granite, limestone, etc. Product CodeDiameter(mm)WingThreadMG-H-225-28,322M14*1 ...