High Speed Steel Burs are known for their hardness & durability. They also stay sharper longer than conventional tungsten vanadium burs. HSS burs are hand fluted which means they may not have the consistency of tv burs. HSS burs have 3/32 shanks and are sold individually. 45 degree are available in sizes from 1.1mm (#2) to 11.1mm(#34).In this shape there is no #23,25,27,29,31,32,33.