... high quality and reliability of the products.Tapered Drill BitType --Chisel Bits / Cross Bits / Button ... ,T45,T51Face Shape---Plate, Concave, Convex.Bit Shank & Coupling sleeve---R22,R25,R28,R32,R38 ... medium-hard rock (1033.5bar~2067bar)Plate ---Suitable for had rock ( more than 2067bar)Drill RodSteel Drill Rod---H19 ... R38,T38,T45,T51. Integral Drill Rod---H19/H22, Diameter---20mm - 42mm. rock drill bits