1)7 7/8''API diamond drill bit 2)pin shank size:4 1/2'' 3)processing:forging 4)sealing:metallic seal 5)MOQ ... /410 5/8,12 1/413 3/4, 17 1/2,22, 24,26417 427 437517 527 537617 637 737Steel Tooth ... /410 5/8,12 1/413 3/4, 17 1/2,22, 24,26115 116 117 215 216 217 315 316 ... /410 5/8,12 1/413 3/4, 17 1/2,22, 24,26M223,M322,M316,M222,M416,M122List of Rock ... ,please feel free contact to me. 7 7/8''API speed drill bit