The hss drill bits are gripped by a spring steel collet into the hex shaft the hex shanks snap into the quick chuck the hex collar is supplied in the sets to enable drills to be removed with two spanners whats included1 x 116 drill bit1 x 332 drill bit1 x 18 drill bit1 x 532 drill bit1 x 316 drill bit1 x 732 drill bit1 x 14 drill bit specifications shank diameter14 inch hex