Hello forum members
I need some advise on my next project.
I bought some years ago a 4 independent jaw chuck with a 4” inch diameter, used a back plate to install it.
I guess it is a Chinese made chuck, not so bad in precision considering it would go to a Grizzly lathe that is also Chinese.
Looks something like this:

Problem is that with time some parts started to get damaged because of a bad fit .
The screws started to stop moving, apparently something was stuck.
The screw I refer to looks like this:

The ones I have had a very bad finish specially on the center where the thrust bearing fits.
I later found that some thrust bearings were broken and that was the cause of a bad fit .

It is difficult for me to get one of those chucks in Mexico, and I could try to import one but when I saw how the thrust bearings look it does not seem to be a difficult part to make.
But I do not have a clue on what material to use because it looks like the originals were made from a stiff material.
I thought on using maybe bronze or stainless steel but I read that there is a tool steel that can be machined easily and then temper it using high temperature. I think it is called O1. Or maybe some other metal?
What would you recommend for this task, or maybe you suggest to get another chuck and avoid all this?
In advance thanks for the advise.