Tap holders
— devices for working with taps (see the relevant paragraph) — or rather, for using in manual format those types of taps that allow it (see "Type of tap").
The tap holder is in fact a kind of wrench. It usually has a T-shape, while a tap is installed in the “leg”, and the crossbars serve as handles for turning. Such knobs are usually designed for a certain range of tools — for example, metric taps M3 — M8 (these details are specified in the specifications). They can be of different lengths; the traditional version is about 100 mm, however, there are devices of 250 mm or more, suitable for threading at a considerable depth. There are also tap holders with a ratchet mechanism (ratchet), which allows you to turn the tap in one direction without intercepting your hand. They are convenient, in particular, when working in cramped conditions, where there is no room for turning the handle through 360 °; and the reverse movement necessary to remove the chips is provided by turning off the ratchet or changing its mode.