Taps
prices on 1239 models— taps are tools for cutting internal threads.
Such a tool is a rod with cutting edges in the form of a characteristic notch; in this case, the first turns of the notch are directly responsible for cutting grooves and are called the cutting part, and the rest are the calibrating part, “finishing” and leveling the cut turns. When working, the tap is inserted into a manual tap holder (see the relevant paragraph) or a machine chuck (depending on the type — see "Type of tap"), then the working part of the tap is placed in a pre-prepared hole, and due to rotary movements, a thread is cut. In this case, you need to turn the tool alternately in the working and in the opposite direction — to remove chips.
Note that in the classic version, manual threading of internal threads involves several passes. Most often, three passes are made (with a rough, medium and finishing tap), but in simple conditions two are enough, and when working with individual materials, up to five such repetitions may be needed. Thus, hand taps and hand-machine taps (see “Type of tap”) are most often sold in sets of several. The machine method, in turn, allows processing in one pass (with a small thread pitch).