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What material for washer between mill spindle nut and bearing?


Mar 22, 2012
Boston, MA
The machine in question is a Cincinnati Toolmaster 1B. I chose not to put that in the title because I suspect that most/many milling machines have a similar washer with a similar function, so Im curious what is used on other machines as well.
I am replacing the spindle bearings and cracked this ancient 0.030" washer while getting the bearings off the spindle. The images show where the washer lives at the end of the spindle, and a picture of the broken washer. The dimensions of the washer seem to basically match the dimensions of the 7007 spindle bearing that it butts up against (62mm OD , and is ~0.030" thick). might have started out thicker and been compressed over the years? It is currently a greasy brown, but it might have also started out a red/brown color. Best I can tell it has some fiber in it.

If I understand the system correctly, this washer is stationary and acts simply to protect the outer bearing race from the spindle nut as the spindle nut is tightened?
So my basic question is what was this material originally, and what is a suitable replacement modern material if the original is hard to find?
Micarta? Vulcanized Fiber? I have seen Fiberglide PTFE/phenolic washers but have not seen one close to the correct size. Given that the 7007 bearing is a current standard product from many manufacturers, is there a specific name for this washer that would help narrow my Googling?
Also, 0.030" seems to be thinner than any modern washers I have found so far. If my understanding of its function is correct then a replacement washer that is 0.060" (1.5mm) thick will have no negative effect other than that the spindle nut wont screw in quite as far.

Thanks for your help,
Hi guys, thanks for the input. There is no information in the parts list other than "washer". I got a sheet of fiber "fish paper" from McMaster and will cut a washer to size and hope for the best.