1)7 7/8''API diamond drill bit 2)pin shank size:4 1/2'' 3)processing:forging 4)sealing:metallic seal ... 5)MOQ:1pc Fitting1)7 7/8'' ... CODE TCI Tricone Bit3 7/8 ,5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/ ... 737Steel Tooth Tricone Bit3 7/8 ,5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/ ... 5 blades,6 blades)5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 ...