Question on Threading Inserts

[ddickey]

What is the difference between partial and full thread inserts?

 

[3strucking]

Partial profile can cut a range of thread pitches. A full profile insert is for a specific pitch. I have used both and prefer the full profile.

 

[ddickey]

Oh okay. I suppose that could get expensive.

 

[pacifica]

Oh okay. I suppose that could get expensive.

You can start by buying the most used sizes of full profile inserts. I find they are faster to reach the final thread profile.

 

[Winegrower]

I like the triangular V inserts that are vertical. They will cut any 60 degree thread.

 

[ddickey]

So the standup inserts are just a 60° no partial or full form?
This is the style I use.

 

[macardoso]

A full form insert will "top" the thread thus cleaning off burrs and giving better dimensional accuracy to the thread form. Since each pitch of thread has a different depth of thread, the inserts must have different dimensions which gives one insert per pitch (not thread size though, a 20 TPI insert can cut 1/4-20 or 5/8-20). I've only seen full form inserts in the laydown insert type (my preferred one) since it requires a cutting edge next to the 60* V. I would call the standup or on-edge inserts a partial profile.

 

[darkzero]

Same, I've only seen full profile inserts for the layddown type which I also prefer. I use full profile for the thread pitches that I cut often & of course partial profile for the rest.

Aside from cleaning up the crest as mentioned, full profile will also cut the proper root, so technically the thread is stronger as opposed to the sharp V of a partial profile insert. With a full profile insert when the insert cuts the crest & you are within spec on dia, the pitch dia should also end up within spec so really no need to measure for pitch diameter.

 

[macardoso]

With a full profile insert when the insert cuts the crest & you are within spec on dia, the pitch dia should also end up within spec so really no need to measure for pitch diameter.

That is a really good point that I have never thought of. I hate thread wires and I'm too cheap to buy a thread mic.

 

[ddickey]

Any suggestions on where one would buy full profile inserts one at a time?