... hole, DTH bits,Well Drilling,PDC bits,PDC drilling bit,Drag bit,Rotary bit,Oil Drilling,Rock drilling, Three Wings Drag bits1. Drag Bits are made ... Standard or NROD Thread standard or others.2. Various Step and chevron Drag bits are available from 2inch to 17 1/2 Inch ... good feedback because of the quality and price.5. Different Drag bits can be made according to customers drawings or samples ...