... by API&ISO9001:2008 New PDC Bits for water well drilling (12-1/4") we can supply rock bits,tricone ... PDC (polycrystalline diamond compact) grades and shapes applied for rock formations as follows:1. Andesite, marble, metamorphic ... the field of mine, transportation, tunnel and hydroelectric for shelving reticular support.Model114,117,127,437,517,617 ... Delivery Time within 7 work days API 12 1/4" New PDC Bits