Ordliste
Thread cutting — definition
Cutting or forming threads in a cast hole after casting, using CNC or a tap.
This is the standard choice for threads in castings. The hole is cored in the casting and the thread is made afterwards. That gives the correct thread class and a repeatable position — neither of which a cast thread can deliver.
In thread forming the material is not cut away but displaced into the thread profile. That produces no swarf, a stronger thread and longer tool life. Zinc is particularly well suited to it.
The precondition is that the hole is cast at the right diameter. Too tight gives hard tapping and broken taps; too large leaves the thread without enough material to bite into.
Here the threading happens in the same building as the casting. The part does not have to travel to a machine shop and back.