Prop Shaft

[gn7]

You use the slot you like, I'll use the one that works for me.
I have seen the full radius slots try to roll the key under a lot less force than a boat prop. Might be the kick ass set up if the key is precision fitted, and the depth is dead nuts on, but most props and shafts don't get the attention to detail that a rocker shaft is afforded. Specially in the pits of a race.

Used a radius bottom end mill, and a craftsman screwdriver shank for close to forty years and not broken a shaft yet. So I think I'll stick with it until I am making at least 2500HP. Then I'll switch to this.