Tapping is a common and useful manufacturing technique for threads of the workpiece, in this article, we’ll introduce what is tapping and its tool, learn about programming of tapping on CNC lathe and how to tap on a lathe, as well as the difference between tapping and threading. 

Related Read: Drill Tap Sizes Chart

What is Tapping Process?

Tapping in manufacturing is the process of cutting a thread inside a hole, which needs to be drilled with tap drill and chamfered at the end, used for screws or bolts being threaded into the hole. Tapping process is a highly efficient, productive, economical and easy threading method, especially for small threads, it can also produce threads on nuts. 

Tap is the cutting tool for tapping, wound down into a hole, and cuts a thread as it goes. There are many types of tapping tool, choose the right tap based on what type of hole you want to thread. The taps can be divided into hand taps and power taps. Hand taps are the most common tap types, including taper tap, bottoming tap and plug tap. Power taps are the types that should choose for CNC applications or manual machining work, including spiral point tap (gun nose or bull nose tap), spiral flute tap (gun tap), form or roll tap, and more.

Tapping on CNC Lathe 

Tapping is a common operation on CNC machines, G84 g-code is commonly used to program tapping, there are two ways of programming tapping on CNC lathe: tapping cycles that can use the Rigid Tapping capabilities of your CNC Machine; and Long Form programming when a Tapping Head or Tension-Compression Tap Holder is to be used on machines that do not have Rigid Tapping.

How to Tap on a Lathe?

Tapping can be done on the lathe machine by hand or power feed. Use a low spindle speed and cutting fluid is beneficial for the process. The procedure of tapping operation on the lathe is as follows:

1. Mount the material blank in the chuck and fix it

2. Select a proper tap drill, face and center the drill  

3. Set the lathe to the proper speed, drill with the tap to required depth

4. Chamfer the edge of the hole

Here you can check out power tapping on lathes: 

Difference Between Tapping and Threading

1. Taps and dies both can be used as the cutting tools to create screw threads. The process of cutting threads using a tap is tapping, while the process using a die is threading.

2. Tapping is the process of mainly producing internal threads, like the threads inside a nut, and threading is a process of usually making external threads, such as threads on the outside of bolts.

3. In tapping, each size hole to be threaded requires different size tap, but in threading, a single tool can be used in thread milling to make a variety of hole sizes. 

4. Tapping does not allow for adjusting the thread fit, threading has the ability to control the fit

5. Tapping provides the speed advantages, especially the high-speed tapping centers set up with a rigid tap, while threading comes in more flexibility and ability to adjust the thread fits.