42 Tooth Change Gear?


Keith Douglass
 

Does anyone know what a 42 tooth change gear would be used for on a 9” lathe?  I don’t see that tooth count on either the 9B/C change gear chart or in the chart for metric threading.  I have one that came with a 9A I recently purchased and I believe it’s from South Bend based on the part number stamped into it.  Searching the web has turned up nothing.  Thanks!

R/
Keith


Davis Johnson
 

You need it to get 27tpi for 1/8 npt for light sockets.

On 4/5/22 11:15, Keith Douglass wrote:
Does anyone know what a 42 tooth change gear would be used for on a 9” lathe?  I don’t see that tooth count on either the 9B/C change gear chart or in the chart for metric threading.  I have one that came with a 9A I recently purchased and I believe it’s from South Bend based on the part number stamped into it.  Searching the web has turned up nothing.  Thanks!

R/
Keith


G K
 

No 42 in the parts list I have for my SB9c from 1957.  





On Tuesday, April 5, 2022, 10:15:22 AM CDT, Keith Douglass <keith_douglass@...> wrote:


Does anyone know what a 42 tooth change gear would be used for on a 9” lathe?  I don’t see that tooth count on either the 9B/C change gear chart or in the chart for metric threading.  I have one that came with a 9A I recently purchased and I believe it’s from South Bend based on the part number stamped into it.  Searching the web has turned up nothing.  Thanks!

R/
Keith


Keith Douglass
 

Thanks Davis!  That sounded familiar, so I checked the documentation that came with the lathe and found exactly what you referenced.  I appreciate the help!


Keith Douglass
 

Here’s the form:



Ray De Jong
 

Als, its a key gear used in 'fudging Metric threading on the South Bend 9 and 10K. There is a thread on this forum if you are interested. I have cut many Metric threads in this manner and they are quite acceptable for general use if you dont worry about being out of pitch a bit. some are as close as .003" in 5 inches.

On Tuesday, April 5, 2022, 10:11:07 AM PDT, Keith Douglass <keith_douglass@...> wrote:


Here’s the form: