Quote Originally Posted by Donald Qualls
It's very common, however, to find lathes with quick-change gearboxes for which there either doesn't exist a manual change train, or more likely the manual gears were put away years ago and no one now in the shop has ever seen them. Since 25 TPI isn't a standard thread, it's not found in most QC boxes.
Yes the lathe I had access to had a QC box and no change gears. The shutter was a #5, can't remember the brand. Seemed very odd to me at the time a 25 tpi thread, never seen another one.