What is Thread Chasing?
Thread chasing is a method of thread cutting or thread finishing by using a multipoint cutting tool (called thread chaser).
Generally in the usual thread cutting operation (which is done by using a single point cutting tool) requires lower cutting speed and it also requires more number of cuts to get the desired depth of cut.
In the thread chasing operation, multi point cutting tool is used which makes the process fast and thread chasing operation can be performed by semi skilled workers also.
There are two types of thread chasers used for chasing thread.
- Hand chaser
- Tool chaser
Thread chasing using a hand chaser
In this method, the threads are cut on a workpiece with the help of a hand chaser by a little support of hand.
Hand chasers are generally used for finishing the spoiled threads or for increasing the depth of threads.
Thread chasing using a tool chaser
The tool chasers are usually of two types;
- Flat type
- Circular type
They are used for thread cutting on a large scale. The tool chaser is fixed in a tool holder as shown in the above image.
Tool chasers have two teeth, the one is cutting teeth and the other is sizing teeth. The sizing teeth of the tool are used for finishing the threads.
How to chase threads on a lathe?
For thread chasing on lathe, the complete arrangement is shown in the above image.
The short lead screw is rotated with the help of a headstock and change-gears.
The feed nut and tool slides are mounted on the shaft as shown in the image.
With the help of hand operated lever, they can be engaged and disengaged with lead screw.