5/16" shaft, 3/32" key, and 15N-m of torque
 

Stall torque on this would be 15N-m. Can a 5/16" shaft with a 3/32 key hold up to it?

Or, if you have any better ideas, I need to get a 13 tooth 20P gear onto a shaft. And I have to do it quickly, soon, and without too much trouble (I'm going to say that LN2 would probably be too much trouble, as would TIG welding).

Re: 5/16" shaft, 3/32" key, and 15N-m of torque
 

Knowing the problem, I would tell you to simply drill it to 3/8" and chamfer the inside of the gear, weld it, and then machine it back down to the initial size.

Re: 5/16" shaft, 3/32" key, and 15N-m of torque
 

Do you think it would need to be TIGed or could it be MIGed?

Re: 5/16" shaft, 3/32" key, and 15N-m of torque
 

You could get away with mig'in it

Re: 5/16" shaft, 3/32" key, and 15N-m of torque
 

AH! Whats with the welding of gears! Key the shaft and the gear. It will be fine at 15N-m. We had gears in 2004 that were 7" in dia and were under ~240N-m (I believe, could be higher) and we had those on a 1/2" shaft and they were fine with a 1/16 key. You should have no problems with the 5/16 shaft and it would be easier on repairs if it wasn't welded.