Technical data : Drill diameter [mm] : 5,5 Total length of drill bit [mm] : 93 Working part [mm] : 57 HSS PRO DRILL BITS - DIN 338 The new HSS PRO range is an industrial-grade drill bit with outstanding performance and a long service life. This range of drill bits is designed for drilling in steel castings and steel, alloy and non-alloy steel, cast iron, non-ferrous metals, plastic and more. METAL DRILL BIT HSS PRO 5.50MM ** Illustrative photos.