What are tap sets?
Used to cut a thread into a piece of material, taps are used similarly to a drill bit but rather than removing material to create a hole, a tap removes material for an existing holes walls to create a screw or bolt thread. Taps can be used with a tap wrench or with a power tool such as a drill. Forming taps by hand with a tap wrench or T wrench gives you the ability to slowly form the thread ensuring it cuts evenly and smoothly for the best finish. Working with power tools to cut threads can be faster for mass produced work but care must be taken to ensure the thread is cut correctly.
Different types of taps
•Taper taps are used to start new threads in materials that have not previously been cut. This gradual tapered cut allows for a smooth start to a new thread. These are commonly used in tougher materials like alloy steel to create less strain on the tap as well as on smaller diameter holes with thinner taps that are more prone to breaking whilst cutting.
•Second taps, also known as plug or intermediate taps are used similarly to the taper tap, working to create a fresh new thread in material often not having previously been cut. Second taps have a shorter taper but more threads along the cutting length to create more thread, faster. Second taps are one of the most commonly used taps as they can cut fresh threads in material whilst also re-cutting threads in slightly worn or older crossed threads.
•Bottom taps, unlike taper and second taps, are a straight, continuous cutting edge with no taper, meaning threads are cut as soon as the tap enters the hole. The full cutting body allows for threads to be cut right down to the bottom of a blind hole. Blind hole tapping is when a thread is cut into a hole that does not pass fully through a piece of material. The bottom tap is typically only used when an existing thread has been cut either with a taper or second tap or when re-cutting an old thread that may have worn or been cross threaded.