... for 6"~17 1/2" 2.high quality,best price 4.number of blade : ... ,6,7,8,9,... Specifications1.best quality for 6"~17 1/2" 2.high quality,best price 4.number of blade ... :4,5,6,7,8,9,... 1,Application:1,Suit for drilling medium to medium-hard formations.2,Evolute ... /94 153/113 190/153 190/1131-18 Model118,152,215.9,244,311,445Typeall kinds and size PDC bitsApplicablewater well ...