Surface-Set Diamond Bits are set with a singular layer of natural or synthetic diamond utilizing a hard matrix compound on the face of the bit. The diamond set design ensures sufficient overlap to prevent premature wear of the matrix.Surface-Set diamond bits are primarily recommended for use in drilling relatively soft, abrasive, unconsolidated formations that are not effectively drilled by impregnated diamond bits. They are also recommended for use in drilling harder formations where the available rotational speeds and bit loads are insufficient to use impregnated diamond bits due to drilling equipment limitations. Size Available: Q Series: AQ,BQ,NQ,HQ,PQ/AQTK,BQTK,BQ3,NQ2,NQ3,NQTT,HQ3,HQTT,PQ3,PQTT T2 Series: T2 46,T2 56,T2 66,T2 76,T2 86,T2 101 T6 Series: T6 76,T6 86,T6 101,T6 116,T6 131,T6 146, T6S 101 T Series: T36,T46,T56,T66,T76,T86 Z Series: Z46,Z56,Z66,Z76,Z86,Z101,Z116,Z131,Z146 B Series: B36,B46,B56,B66,B76,B86,B101,B116,B131,B146 WF Series: HWF,PWF,SWF,UWF,ZWF WT Series: RWT,EWT,AWT,BWT,NWT,HWT WM Series: EWM,AWM,BWM,NWM WG Series: EWG,AWG,BWG,NWG,HWG Others: NMLC,HMLC,LTK48,LTK60,BGM,NGM,ADBG,TBW,TNW, ATW,BTW,NTW,NXD3,AX,NX,NXC,AXT,T6H,4 9/16,NWD4,412F,SK6L146, TT46,TB56,TS116,CHD101 All Chinese sizes