Roll the thread not cut it??
That no doubt maintains an uninterrupted molecular structure of the spoke end.
It reminds me of the industrial visit my fellow Naval Apprentice Fitter and Machinists and myself went to at Australia Forge where we saw a crankshaft for a BMC 4 cylinder engine formed from a red hot billet of steel with one almighty blow in a thumping great steam hammer.
Afterwards they showed us a crank that had been machined in half and acid etched and illustrated the flow of its molecular structure.
Also reminds me of the difference between a magician's wand and a policeman's baton.
The former is for cunning stunts. The use of the latter I will leave to your imagination.
I hope your cunning stunt goes well chook.
You don't see the allen key for retaining the threading head in the photo, as it is still hiding somewhere under my welding bench. I know it's there as it bounced off the toe of my boot and I heard it strike something. I've looked for a good while with no luck.
....... silly season....too long in the bush 
