On 31st Oct 2021 4:33am, JohnnieWalker said:
You live and learn, eh, MR! Hobbing is like skiving, only different! 
Hobbing would have been used to cut splines pre hardening. Post hardening, splines / gears would have been "skive" hobbed using a carbide hob to remove heat-treatment distortion and produce a fine finish. Today, we finish grind hardened splines / gears.
