# Atlas Press Co (Clausing) 4804 lathe bearings



## ptross (Jun 9, 2020)

I'm replacing the spindle bearings in the headstock and wonder if anyone knows what precision grade the original bearings were? My numbers found on the existing Timken bearings are: 
14125-A
14137-A
both cups:    14276

the cups are marked X-Timken, and the 14125-A is also marked X-Timken. Can anyone tell me if this is significant?
thanks,
Peter


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## wa5cab (Jun 9, 2020)

The ANSI-ABMA tolerance structure groups the tolerances by "Class".  From loosest to tightest tolerances, the tolerances are defined as Class 4, 2, 3, 0 and 00.  Timken itself has a Class that would be 000.  No one seems to know why the odd number progression.  As far as we know, Atlas Press Co. used Class 3.  From around 1935 until about 1952, someone but probably Timken did 100% inspection of the bearings that Atlas was buying and engraved a date on both the cup and the cone.  Sometimes they also  engraved a "3".  

Atlas Press bought Clausing in 1949/50.  Over the years, the Clausing contingent apparently got the upper hand and the combined company name was Atlas-Clausing, Clausing-Atlas and just Clausing.

Fairly soon after the purchase, the model numbers were changed and the Clausing 100 Series became the Atlas-Clausing 4800 Series.  AFAIK, we do not know what Class the bearings in the 4800 were but it is probably safe to assume that they were Class 3.  You probably can't afford Class 3.


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## ptross (Jun 9, 2020)

thanks for the thorough response. my bearings do have a date engraved, and a "3", though I couldn't tell at first if it was a 3 or an M.


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## ptross (Jun 9, 2020)

if I were to buy class 3 bearings from Timken now, how would they be marked differently from other class levels? Is there any way to identify a bearing class if not buying from the manufacturer?


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## wa5cab (Jun 10, 2020)

I don't know whether the cup and cone would be marked or not.  I know that around 1952/3, Atlas on their Atlas badged product quit having Timken engrave the inspection dates on the spindle bearings.  I haven't heard of any of the spindle bearing in the Clausing badged lathes that were so marked.  I do know that a Class number could only be assigned (or more correctly, any number assigned could only be valid ) if the cup and cone were purchased together.  I would seriously doubt that the hand engraving that was done in the 30's, 40's and early 50's would be done today.  And I would guess that you would have to buy the cup and cone as a matched set.  And unless you were buying several hundred sets, probably you would have to buy them directly from Timken.  Last that I had heard, Timken was one of the few US manufacturers still making anything in the USA.  Unfortunately, if the class was printed on the box, you couldn't really trust it unless you could somehow confirm that both the box and the contents actually came from Timken.


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