slot drill

Ball nose cutters or ball end mills (lower row in image) are similar to slot drills, but the end of the cutters are hemispherical.

Creating an external keyway on a shaft is simple if you have access to a milling machine, A suitably sized slot drill will produce the form required to fit the key.

Links Click on the above links to see further information Accessories include various wheel arbors, end mill and slot drill holders, lathe tool holder and slitting saw holder.