The larger cross section (58% more mass) of 8mm shank bits makes them considerably stronger than 1/4" shank bits, resulting in smoother, faster cuts with less chatter and greater safety. 12 piece set contains all the cutters in the 7 piece set plus Leigh cutters 90,100, 150,160 and a1/2" - 8mm reduction sleeve (172-8). Set is supplied with wooden storage box.
