Challenge 27 shaft

[Kenneth]

Can anyone suggest what material to use for the Challenge 27 shaft for the bull gears. I see in the literature, it says this shaft is case hardened. Will I have to quinch this shaft?

Thanks, Kenneth

[RPinAZ]

I have zero experience with this particular part, but usually, you would only case harden something if you needed a wear resistant surface on a lower grade steel. The alternative would be to just use a better steel. If it were me, I'd probably use either 4140 or stressproof (1144), the later because it machines so nice and is hardenable, although you probably wouldn't need to harden it.

[Kenneth]

Thank you RPinAZ for your response. I have found some ground 4140 HT that I think I will use. That is close tolerance and should work fine. I will keep you all posted.