1)7 7/8''API diamond drill bit 2)pin shank size:4 1/2'' 3)processing:forging ... Size BitsHejian baoxing Petroleum Machinery Co., Ltd.ProductSizeIADC CODE TCI Tricone Bit3 7/8 ,5 1/2, 6 1/27 7 ... ,22, 24,26417 427 437517 527 537617 637 737Steel Tooth Tricone Bit3 7/8 ,5 1/2, 6 1/27 7 ... /2,22, 24,26M223,M322,M316,M222,M416,M122List of Rock BitsStructureI you need more information,please feel free contact to ...