Xi'an Tydrillbits Co.,Ltd is one of the most famous China pdc core bit manufacturers, welcome to wholesale cheap pdc core bit, diamond core bit, tungsten carbide core bit from our factory.  PDC Core Bits are manufactured with very small, high quality pdc insert , mixed evenly through a metal alloy matrix. The matrix erodes away at the same rate as the diamonds become worn and rounded. In most geological formations, impregnated bits are more economical to use than other bits. Double tube surface Size( surface exploration drill Matrix system(mm) Imperial system( in ) Hole diameter Core diameter Hole diameter Core diameter BQ 60 36.4 2.36 1.43 NQ 75.7 47.6 2.98 1.88 HQ 96.1 63.5 3.78 2.5 PQ 122.7 85 4.83 3.34 Triple tube surface NQ3 75.7 45 2.98 1.78 HQ3 96.1 61.1 3.78 2.41 PQ3 122.7 83 4.83 3.27