AMMASHOOTA
Gary Gruber
I am curious to know how an interrupted thread is machined. i have searched online but can not find a step-by-step that illustrates the process.
interrupted thread
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jackie schmidt
New member
???
i am not quite what you mean by an interupted thread. If you mean it has a slot or keyway in it, that is probably machined after the piece is threaded. If the slot is machined first, I don't see the problem......jackie
i am not quite what you mean by an interupted thread. If you mean it has a slot or keyway in it, that is probably machined after the piece is threaded. If the slot is machined first, I don't see the problem......jackie
D
dipper
Guest
What Jackie described is a common type of interrupted thread---something that has a keyway or slot in it.
It is always much easier to do your threading first then mill or surface grind or broach etc. your keyway/slot after threading is complete.
There are two reasons to thread first:
You don't have an interrupted cut on the lathe--that is your tool does not "leave" the workpiece, cross the slot, and then contact the workpiece again--a interrupted cut is not as smooth as a continuous cut and it is much easier to file or polish your threads with out the slot in place first.
There are times when I had to thread with the slot cut first but I prefer not to if I have a choice.
Oh, it can also save you a chipped toolbit/insert too.
Rich
It is always much easier to do your threading first then mill or surface grind or broach etc. your keyway/slot after threading is complete.
There are two reasons to thread first:
You don't have an interrupted cut on the lathe--that is your tool does not "leave" the workpiece, cross the slot, and then contact the workpiece again--a interrupted cut is not as smooth as a continuous cut and it is much easier to file or polish your threads with out the slot in place first.
There are times when I had to thread with the slot cut first but I prefer not to if I have a choice.
Oh, it can also save you a chipped toolbit/insert too.
Rich
AMMASHOOTA
Gary Gruber
i am referring to the type of thread cut for take-down rifles. perhaps i am using the wrong terminology to describe it. it is the 1/4 turn lock that occurs when the two pieces are mated. I have seen many photos of them, i am just curious how they are actually milled.
P
PPP MMM
Guest
The curiosity killed the cat
A very simple procedure. The mating threads are made in full and screwed together with a desired amount of total tension, then marked and than turned back by the amount of desired turn/degrees (usually 90 degrees) and the sections of both of the opposite threads are milled off in a reverse order. Just like a bolt/receiver of a bolt action.
In a simple term it will screw the opposite threads only the last 90degrees(1/4) of the very last turn to make a full contact of the mating shoulders.
Shoot well
Peter
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A very simple procedure. The mating threads are made in full and screwed together with a desired amount of total tension, then marked and than turned back by the amount of desired turn/degrees (usually 90 degrees) and the sections of both of the opposite threads are milled off in a reverse order. Just like a bolt/receiver of a bolt action.
In a simple term it will screw the opposite threads only the last 90degrees(1/4) of the very last turn to make a full contact of the mating shoulders.
Shoot well
Peter
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