... working life 2.over 30 years experiences 3.fast speed 4.reasonable pric Impregnated core drill bit(BQ,NQ,HQ,PQ ... or banded geological formations. Their multi-layered cutter arrangement results in better overall bit life than bits produced with other types ... 1/2AWF,BWF,NWF,HWF,PWFAX-AWT2-10166mm6x7-3/4NWD-4,HWD-4BX-BWT2-11676mm3-1/2x2-1/8AWC-3,BWC ... 116 TS-136 TS-146 Impregnated Core Bit HQ (Made in China)