# A B Or C



## mudwizer (Feb 23, 2015)

How do I determine what 9"
Lathe I have a b or c I want to order some parts  thanks


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## compsurge (Feb 23, 2015)

I hope this link helps. You can decode the serial number.

Here is where it is located on the ways (it may be under the tailstock).

http://www.southbendlathe.com/products/serial_numbers


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## Andre (Feb 23, 2015)

A = QCGB + Power Feeds

B = Conventional Change Gears + Power Feeds

C = Conventional Change Gears (No power feeds except with the leadscrew, which should only be used for threading)


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## Surprman (Mar 12, 2015)

A = QCGB + Power Feeds

B = Conventional Change Gears + Power Feeds

C = Conventional Change Gears (No power feeds except with the leadscrew, which should only be used for threading)

Andre - why should the leadscrew ONLY be used for threading on a Model C?  I have a model C and use the split nuts on the lead screw all the time to get a great finish (compared to manually advancing the carriage).  I'm pretty sure that SB did not intend to sell a lathe with no power feed at all, so the split nuts were meant to perform this function on that model (in addition to threading).  Are the A and B models more convenient?  I'll bet!  In a production-type environment (where time is money), their functions would be more of a necessity but the model C is not all that bad for a hobby machinist doing smallish work (my target activities). 

Rick


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## Mark_f (Mar 12, 2015)

Yes, I have a Dalton screw lathe which is similar to the SB c. (only the lead screw feeds with half nuts) You can feed with the half nuts as long as you have the gears for the feed rate desired. The only draw back may be prematurely wearing out the half nuts using them for feeding, but for hobbyist use that probably would not be a big concern. My Dalton is over 70 years old and the half nuts are still in good shape. I think it is a matter of opinion.


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