... 2008 API 8 1/2" 5 Blades New PDC Bits for Oilfield Drilling1-API or ISO 9001:20082-Delivery Date: In 7 ... bits, steel tooth bits, milled tooth bits, rock bits, oilfield bits and so on .Specification: diameter from 3-1/8 ... in the field of mine, transportation, tunnel and hydroelectric for shelving reticular support.Model114,117,127,437,517,617,637 ... 7 work days 8-1/2" New PDC Bits for Oilfield Drilling