Amana Tool 51572 Bullnose 2-Flute Carbide Tipped Router Bit with Ball Bearing Guide, 1/2-Inch Shank Cutting diameter 1-3/8-Inch 1-5/16-Inch cutting height, 3/8-Inch radius 35/64-Inch nose diameter (thickness of stock that can be nosed, i.e., given a full 180-Degree round over) 1/2-Inch shank, 2-flute. Carbide tipped, industrial quality. Maximum RPM = 20,000! For use only in a table mounted router only, not for use in a handheld router.