for a free-running nut, and the adjustable die can do this.
It is also possible to cut an undersize thread by rerunning the thread with the die held at an angle. This
makes the die cut some off the side of the previously cut thread, but it will not be a true and even thread.
It is to be used only when an adjustable die is not at hand and never where accurate threads are
required.
For cutting threads in the lathe with these button dies, use a die holder that it's in the tail stock. This has
a guide portion on which the die can slide as it feeds onto the work. The thread is started by putting
pressure on the die with the tail stock.
After it is started, the die will feed itself. The lathe can be run under power, using the slowest speed of
the back gears. On completion of the thread, the lathe is reversed and backed off the die.
When backing off the die, be sure to remove the amount of feed used to start the die, or the die will stop
backing off when the free travel is used up and will chew up the threads.
It is best to unclamp the entire tail stock from the bed as you start to back off, you can then be sure the
die can work all the way off without doing any damage. A little sulfur-base cutting oil should be used on
both taps and dies. With brass and aluminum, the taps and dies tend to stick to the metal unless oil is
used.
THREAD DIMENSIONS
All of the thread sizes shown here were taken from the workbook that we made up as we threaded new
barrels, and came directly from the old barrel. They may or may not agree with some of the factory
specifications found in some books. The sizes given below were what we cut on the new barrels and
reinstalled back on the old action.