Bi metal hole saw kit - includes 1 x circular hole saw, 1 x HSS pilot drill & 1 hex shank arbor that will fit into any standard drill chuck that goes upto 13mm - either a hand drill or a pillar drill. Our HSS M35 Cobalt Bi-Metal holesaws have a variable pitch tooth pattern which ensures smooth cutting and less "chatter" when drilling metal, particularly thin sheet. Made from high quality M35 grade 5% Cobalt HSS steel cutting edge and compatible with most makes of arbor.