Tap hole Drill rod and bit are widely used in big steel mill ... ASTM A53B, ST45, ST42.(2)Out diameter: hex.19mm, hex.22mm ,hex.28mm , hex.32mm, dia.32mm, dia.38mm ,dia.45mm ... to worldwide clients’ different condition.—MAXDRILL Tap hole Drill Bit (1)Diameter:38mm-70mm.(2) shape, carbide 3 ... -blade type , steel cross bit , carbide cross bit ,button bit andetc(3)Package: in wood case or in ...