Ruko 106 340 8 piece hss bi metal hole saw set with variable toothing ruko 106340 the ruko hss bi metal hole saws in this 8 piece set have varied tooth spacing and are suitable for unalloyed steel up to 700 n mm sup2 strength non ferrous and light metals plastics plasterboard and light building boards fibreboard plywood and wood they are particularly suitable for use with hand drills pillar drills and lathes ruko 106340 hss bi metal hole saw set with variable toothing 8pc