Drilling v tapping: the differences
Drilling is the process of creating a hole in a material, typically using a drill or motor. This differs from tapping, which is the process of creating a thread within a hole. This process is used, for example, to get a nut ready for a screw or a bolt to be threaded into the hole. The process for creating the thread on the outside of a bolt is different again. This process is called threading and typically uses a die to create the thread.
Tapping is usually done with a tool known as a tap. Taps come in different sizes and variations. Which one you choose often depends on the material and type of hole that needs to be threaded. Tapping can be done by hand or with pneumatic or electric tapping machines.
Types of tap
Hand taps come in three variations; taper, plug and bottoming taps. Taper taps offer a very gradual cut, suitable as a starter tap for blind holes. Plug taps are the next step up and a better choice for through-holes. Bottoming taps are generally used to finish off the tapping started by other types of tap.
Spiral flute taps work more like a drill bit and are suitable for soft metals. They’re not as strong as hand taps so shouldn’t be used on harder steels. Straight flute taps are much stronger and suitable for cutting into harder materials but care must be taken to avoid chips damaging the thread during use.
More details on sizing and hand tapping can be found here:.
Electric tapping
Electric tapping machines automate a lot of the process and can provide better accuracy, higher throughput and a range of safety features. They typically come with both manual and automatic modes, so it’s possible to use them for manual work as well as production. Electric tapping machines can tap much faster than other methods, which is why they are best used for volume work. They can also tap much deeper into harder materials giving them an advantage over other methods when materials such as hardened steel are involved.
