... ISO9001:2008 8 1/2" New PDC Bits for Well Drilling Description about sell rock bits,tricone ... (polycrystalline diamond compact) grades and shapes applied for rock formations as follows:1. Andesite, marble, metamorphic ... field of mine, transportation, tunnel and hydroelectric for shelving reticular support.Model114,117,127,437,517, ... box, steel box, or as your requirements Payment Term T/T or L/C at sight MOQ ...