STUBAI - Austrian made, heavy duty roughing down tool. There are 7 series #52 sweep patterns, A,B,C,D,E,F & G each available in 50, 60, 70 and 80mm widths.
Austrian made, tool steel bits with dual rim lips and wide chip gates which don't bind up. These cut a hole as cleanly as forstners and are easier to hone and sharpen.