What's new
What's new

South bend 13 cross feed screw variations

Pmat

Plastic
Joined
Mar 16, 2014
Location
Maine USA
In looking at the south bend lathe parts manual, there are two part numbers listed ( 20 and 21 ) but only one (non-taper attachment) pictured which is 20. It is labeled direct reading dial. However there is only one nut listed which is part 56 labeled English threads.

Can anyone tell me the difference between the screw labeled 20 and the variation listed as 21?

I am wondering because I bought a used screw on eBay which appears dimensionally correct except it will not screw into my existing cross feed screw brass nut.

Is one part designated for a direct reading dial and the other for non direct dial? Or is one variation metric?

Thanks,
Paul
 
A little further investigation reveals that the replacement screw I purchased is 8 1/2 tpi while the original is 8 tpi. I used a caliper, in 4 inches the new screw has 34 threads while the original has 32. No wonder it won't thread on! They both measure .625 in thickness and every other aspect appears to be identical.
 
I am the one that sold Paul the screw. I would also like to know if they used two different threads in the 13" lathe. I checked the screw with a new nut I had and it fit. I have 2 more screws and they also fit the nut. Then I found another nut and they don't fit that one. The nut they fit has a M stamped on the side. Did South Bend make a Metric 13" lathe?
 
I am the one that sold Paul the screw. I would also like to know if they used two different threads in the 13" lathe. I checked the screw with a new nut I had and it fit. I have 2 more screws and they also fit the nut. Then I found another nut and they don't fit that one. The nut they fit has a M stamped on the side. Did South Bend make a Metric 13" lathe?
Yes, SBL made metric 13" lathes as well as the 9",10", and 16" (and the shaper)
The metric components were marked with a "M".
Ted
 
Like to point out that Dick sent me a refund, very honest decent eBay seller.

We both learned something.

Paul
 








 
Back
Top