... 5,6,7,8,9,... Specifications1.best quality for 6"~17 1/2" 2.high quality,best ... 6,7,8,9,... 1,Application:1,Suit for drilling medium to medium-hard formations.2,Evolute ... cuttings evacuation requirements with available hydraulic flows.Allows for higher flow rates with minimal increase in pump ... applications 2.details: Bit typeMain bit size(mm)Rock coefficientPDC core drill bitSingle pipe75/54.5 94/ ...