Along with the diameter and thread type (BSP, UNC, metric, etc.) of the holes you need to produce, you must also determine the best end point, taper, and flutings for your thread taps based on your application.
The tap’s end point can be formed with a short twist in the threads, as seen on high-performing spiral point taps. The thread tap’s taper is the slope at its cutting end. Taps with the longest tapers are taper taps. Plug taps have shorter tapers and bottoming taps have none. A given tapped hole will often require using more than 1 of these to fully complete its threads.
Flutings are the void sections cut out of tap threads. Choose a fluting style based on the types of chips your workpiece’s material will form as it’s cut. Straight flute taps are meant for more brittle material, which forms fine chips, while spiral flute taps can handle the stringy chips that softer material forms.
Taps can also create threads by cutting material away or compressing and deforming material without cutting chips. This latter process involves forming taps.
Whatever your application is in these categories, RS offers a thread-tapping tool to achieve it.