Cutting stock
A die stock , die stock , formerly sometimes Gasrohrkluppe , or shortly nipper is a tap that for the production of external threads on pipes in the plumbing , heating and air conditioning systems is used.
In Germany, conical Whitworth threads are usually cut on medium-weight and heavy-duty threaded pipes according to DIN EN 10255 ( formerly DIN 2440, 2441 and 2442 ), which are available up to a size of 6 inches (DN 150). From a size of 2 inches, however, flange connections are preferred .
The thin-walled " boiler pipes " according to DIN EN 10220 or DIN EN 10216 and the modern "precision steel pipes" according to DIN EN 10305-1 to -4 (formerly DIN 1630, 2391, 2393, 2394 and 2445-2) are not suitable for threaded connections.
When using a manual clip, the threaded pipe is clamped in a pipe vice to hold it against it. Manual cutting clips usually consist of a lever that is screwed into a mounting ring for the actual cutting dies. Usually three cutting jaws sit in their own receptacle, which is driven by the outer receptacle ring via a ratchet mechanism , so that it is sufficient to move the lever back and forth within a certain angular range.
Electrically powered die clips are also available.
A suitable thread cutting oil or thread cutting agent must be used when cutting.