Die holders
— devices for working with dies (see the relevant paragraph); another name for such instruments, common in the professional field, is “klupp”.
Die holders are a specific type of crank: a double-sided handle with a hole for installing a die in the middle, or one-sided, with a seat at one of the ends. The die is fixed in such a knob with the help of special clamps — usually screws. The size of the seat is usually indicated in the specifications with two numbers — for example, 90x36; the first digit indicates the diameter of the mount, the second — the height (in mm). The thread diameter for which a particular holder is suitable is usually specified in the detailed specifications; however, on average, this diameter is somewhere in 2 – 1.8 times smaller than the size of the seat under the die. So, in the example mentioned above, with a 90 mm seat, compatibility with metric dies from M45 to M52 and similar sizes of inch dies can be provided.
Also note that die holders can be equipped with a ratchet mechanism (ratchet), which allows you to turn the tool in one direction without intercepting your hand. Such clamps are convenient, in particular, when working in cramped conditions, where there is no space 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.