I recently purchased a used 4-jaw chuck for my Atlas 12" lathe.

The problem is that none of my chuck keys will fit it. The 3/8 is too
large, and the 5/16 marginally too small, so unless it's some *******
metric dimension, an 11/32" inch square chuck key would be perfect.
The problem is that I can't find any on eBay or even in the tool
catalogs.

The question is: "Does anyone know where a can purchase a 11/32"
square chuck key for a lathe 4-jaw chuck?

Thanks in advance.

Harry C.