We had the crank break in a McCoy .50 once years ago...the prop/spinner and all flew off. We had a buddy that was a machinist make a new one. It looked just like factory, and we ran it a couple times after that, but can't remember much about how hard it had to be. It could be that it was hardened after he made it.
I thought you flew that monster at an EAA compitition?
Nope, I had entertained the thought of John Wayne-ing it on a short tank and conventional lines, but backed out. I'll hafta find insulated steel cables so I can control the throttle. But first I'll hafta cut into the starboard wing because I stripped the mini-srevo for the throttle. It seems they are very delicate!
I was about to suggest same sources as above. Another is Advanced Global Materials. Direct Phone: 631-286-8570 I think they are on Long Island. They have web site and you can request quote online. Many other steel distributors out there who cater to aerospace & energy industries.