TABLE OF CONTENTS Threading is a machining process used to produce a helical groove of a given shape and size, usually on a cylinder (straight thread), or on a cone (tapered thread). The major purpose of threads is to connect two parts together without damage during joining and disjoining (assembly and disassembly). The most common applications of threading fall into four major categories:
| screws, bolts and nuts |
| micrometer barrel |
| lead screw, camera lenses |
| lifting or supporting jacks |
Thread cutting is a very versatile manufacturing process. There are two main groups of thread production - metal cutting and plastic molding. It should not be a surprise that it is the plastic molding method that dominates manufacturing industry. Given the number of detergent bottles, pop bottles and other plastic products we consume, the number of threaded products using this method is astronomical.
In metalworking area of thread production - the primary group of interest - there are smaller several subgroups:
Thread rolling
Thread forming
Thread grinding
Tapping and die work
Thread milling
Single point thread cutting
For a typical CNC programmer, the areas of interest are usually confined to the last three - tapping (but no die work), thread milling and single point threading. Methods for tapping operations have been described in Chapters 25 and 26, thread milling will be described in Chapter 45. This chapter covers programming methods described as single point threading.
