Lotus steel tooth tricone rock roller bits as per api standards and specifications:open bearingbit size: 2 78" with n rod to 17 12" for soft med hard formation.Api pin connection: n rod (4 tpi) or aw to 6 58 or 7 58 reg.Sealed bearingbit size: 6 ", 8 , 12 & 17 " for soft med hard formation. api pin connection: 3 regular to 6 58 or 7 58 regular lotus tci tricone rock bits as per api standards and specifications:open bearingbit size: 4 34" to 17 12" for soft med hard formation.Api pin connection: 2 78 regular to6 58 or 7 58 regularsealed bearingbit size: 6 ", 8 , 12 & 17 " for soft med hardformation.Api pin connection: 3 regular to 6 58 or 7 58 regular