No it's not tapered. Thanks.Does the body have a taper? I am with Bill. We used something similar when we were making plastic injection moulds. Ribs always have a taper and can be formed by a tapered end mill. And to provide better drop test performance on our tools we would specify a radius at the bottom of each rib. This was a pita for the machinists and often were not included. If it is indeed tapered it is often stated on the flat of the weldon shank where the set screw lands.
David