- Double ended drill bits are derivative of HSS-G and both ends are drills - Cutting edge: 135° split point geometry which ensures no walking and slipping. - The total and working lengths are shorter than other HSS drill bits. - Application: While drilling many holes on thin metal sheets, double ended drill bits are preferred because of their short length and long life. Bit Dia (D) (mm) / 6.0 Overall Length (L1) (mm) / 66 Working Length (L2) (mm) / 19.0 Per Pkg / 10