Can someone decipher lathe build date?

[great white]

I’ve always though my TH42 (10F) was a mid fifties build, but in tearing it down to paint, I’ve found some casting numbers in the bed ways.

I’ve read that there is usually casting numbers between the ways and its roughly a year prior to when the lathe was “built”. Seems the story goes that Atlas had the ways cast and ground and then left to age for about a year to let it warp or twist if its going to.

The casting marks are not exactly definitive. One mark is just a “W” in a raised oval and the other is “842” by itself. no other casting marks were evident.

The lathe data plate;


087321.

Coukd the casting number mean 8 month 1942? Which I guess woukd mean its around a 1943 build date?

I thought maybe its part of a julian date code, but 842 isn’t on a julian calender.

Anyone want to take a swing at what the build date is?

 

[pontiac428]

Look up @wa5cab's Atlas date thread and see. As discussed in the thread, there are inconsistencies and the bearing date is the key, but you can narrow it down with the serial #/date spreadsheet that he's built.

 

[great white]

Look up @wa5cab's Atlas date thread and see. As discussed in the thread, there are inconsistencies and the bearing date is the key, but you can narrow it down with the serial #/date spreadsheet that he's built.

I did consider the date code on the timken bearings, but I don’t particularly want to remove the spindle just to check dates. I may, however, have to remove the spindle if I can’t get the paint results I want without pulling it...

 

[pontiac428]

The date code on the bearing could be read by removing the caps and rotating the races to read them, you don't need to pull the spindle shaft. The date code is etched on the outward facing edge of the outer race. But if you haven't torn down the head yet, it's silly easy.

 

[great white]

How would I remove the bearing covers without destroying them? They look like a press fit and without pulling the spindle, I can’t quite think of how you would get them out without distorting them.


Maybe I should go look a little closer at the head….

 

[pontiac428]

Oh, crap, I was thinking about my Atlas (has caps) not yours (Timken head has no caps). Yeah, you have to pull the spindle. My bad.

 

[great white]

Decided to just pull the spindle since I’m painting the head.

only one bearing shell was marked:



So now I know its at least no older than 5-22-51.

What year it was put together and sold is a guess. I’m guessing roughly end 51 start 52…

 

[wa5cab]

First off, all of the Atlas lathes with Timken bearings have the pressed-in dust covers. The ones that do not have them are the 10" and early 12" with babbit bearings and the early MK 2 6" with ball bearings.

From the serial number I was going to guess late 1951 or early to mid 1952. Am I correct in reading what you wrote that the cup of the dated cone and neither cup nor cone of the other bearing is dated? I will also mention that this is the only one that I have seen dated with black ink. Every other one has been dated with a vibrator pen. We have one set of bearings dated in August of 1951 but there is a note added that the handwriting is terrible. So the "8" might have been something else.

The information pertaining to a year or more between casting and any machining comes from a paragraph written in the various MOLO's.

I have no idea what the number in the casting could mean.
the "42" may have nothing to do with the fact that it is a 42" bed.

In most of the dates reported or seen, both cup and cone were dated. About half were the same date and half were not. The record for differences between dates on the two bearings is from memory eleven months.

 

[pontiac428]

1951? Hmm, I couldn't find the color until 1956. Too late now?

 

[great white]

First off, all of the Atlas lathes with Timken bearings have the pressed-in dust covers. The ones that do not have them are the 10" and early 12" with babbit bearings and the early MK 2 6" with ball bearings.

From the serial number I was going to guess late 1951 or early to mid 1952. Am I correct in reading what you wrote that the cup of the dated cone and neither cup nor cone of the other bearing is dated? I will also mention that this is the only one that I have seen dated with black ink. Every other one has been dated with a vibrator pen. We have one set of bearings dated in August of 1951 but there is a note added that the handwriting is terrible. So the "8" might have been something else.

The information pertaining to a year or more between casting and any machining comes from a paragraph written in the various MOLO's.

I have no idea what the number in the casting could mean.
the "42" may have nothing to do with the fact that it is a 42" bed.

In most of the dates reported or seen, both cup and cone were dated. About half were the same date and half were not. The record for differences between dates on the two bearings is from memory eleven months.

correct. Only the front cup has a date on it and it's what you see in the pic above. The rear race definitely does not have a date code. I'll pull the bearings out of their baggie and look again, but I'm pretty sure neither was dated.

Doesn't look like a marker, it certainly does not rub off or fade like an ink would. It looks like an acid etch or something similar....