Chrome-Moly-Nickel steel

Hello

I need to remove about 8 thou from the diameter of some 7/8" rods of the above material.

What is the best way of going about it on a lathe please?

The current finish on the rods is impressively smooth. Needle rollers will be running
on the reduced diameter surface, so I need to get an appropriate finish.

Regards
Doug

 

80? That's a lot, I might do 1 or 2 on the lathe, but for 80 pieces I would drag out one of the surface grinders and get it fired up. You might try turning one piece to see if you can cut it, but if that doesn't go well then grinding on a real grinder (cylindrical, surface, or tool & cutter) would be the only real option. As you said, all of that grit in the lathe would not be a good thing.

Yes, grinding is best done on machines designed for grinding ---

 

From the description, I suspect that you have chrome rod, which is used for hydraulic cylinder shafts. It is medium carbon steel which has been plated with hard chrome and ground. You will not be able to turn the chrome plating, though if you take a deep enough cut, you can get underneath the plating. Surface finish is also critical for needle rollers.

Here's a comprehensive treatment of the types of bearings and requirements.
https://www.ntn-snr.com/sites/default/files/2017-03/needle_roller_bearings_en.pdf

Your best bet is Thomson Case 60 shafting, which is available in both metric and imperial. It's the stuff to use for needle roller and linear bearing applications. https://www.thomsonlinear.com/en/products/shafting/quick-shaft-products

There are also inner races (hardened and ground bushings) which will work for this application that can be pressed on a shaft.
https://www.astbearings.com/inner-rings.html