TABLE OF CONTENTS Many part programmers who have the opportunity to program single point threading operations for CNC lathes, have been accustomed to using the venerable G76 multiple repetitive cycle. Without a doubt, this is a modern and very flexible cycle that can be used for the majority of standard threading applications, external or internal. Threading operations can be very simple or they can be quite complex. There are many thread forms, many different specifications, many standards, and many different expectations. Some CNC programmers share a common view that threading on CNC lathe can be either very smooth or very difficult. The underlying message is that there is no in-between situation. Of course, this is not exactly the most accurate view, but it does illustrate certain frustrations that programmers and operators alike have to go through while programming or machining threads. Using a single arbitrary programming method for all threading applications is not always the best choice in fact, it may even be the wrong choice.
Although the most common thread form is the 60 V-shape thread, used for both metric and imperial threading, there are many other thread forms that can be programmed and machined using a typical CNC lathe (turning center).
When it comes to machining, there is practically no subject larger than that of threads. Threads are everywhere, and they have so many different purposes, so many different forms, that even a seasoned CNC programmer may say find the subject of threading overwhelming. The...
