Tapping Vs Thread Milling

[ALLtra Mach]

We are looking at getting into thread milling.
Just wanted to hear everyones pros and cons before I spend lots of money.
What type of mills do you like, single point, multi flute, brand name?
Single or multiple pass?
So far I am 50% with the "experts" as to which is faster.
I don't care about tooling cost, I look at per hole expense.
And I am looking at this from a production and Quality stand point.

Any way, some help here guys. Write me books, long post are good post.
Thanks

[JWB_Machining]

Personally I Like tapping best but ovsiously in some situations it may not be feasible and buying taps of all different sizes ends up being more expensive over time than thread milling with an indexable thread mill. My indexable thread mill has a 1/2" sweep though, so any hole smaller then that I have to tap. Thread milling does offer the advatnage of doing various sized holes with just one insert. I did have a problem using a extended solid carbide thread mill when threading down an inch in steel, I experienced terrible chatter and had to take multiple passes to complete the thread. Short thread mills (1/2") are very rigid though and can get the job done in one pass. Another advantage with thread milling over tapping is that with taps once you run it, that's it the threads are that diameter and there's not much you can do, so if you're trying to screw something in whose threads are a lil larger then the tap you're kind of screwed. With a thread mill you can go as shallow or as deep as you want so you can ensure you're gettin the fit you want.

I'm sure others on this site will have a lot more info with thier experiences but if I have the Tap and it's a through hole or a blind hole that's deeper than my threads need to go I like to tap, but obviously on some blind holes thread milling really is the only option.

Another advantage of the thread mill is you can do exterior threads so you don't have to buy dies. Just make sure you're using the right insert.

I'm young though, so I'd look to see what some of the older and more experienced guys have to say. For all I know everything I just said is wrong haha.

[mc-motorsports]

subscribed. Interested in hearing what others have to say.

[miljnor]

You pretty much covered it


But here are some thoughts.

You have to be able to do either.....taps are pretty much the only game in town for the small stuff. And the large stuff or (like you said) the OD stuff is pretty much all Thread milling.

Thread milling is also more friendly to large production runs and has the advantage of not ruining the piece (in a lot of the cases) when it goes bad...you can just re-run the new thread mill.

Taps often break in the piece and either ruin it or cost you money removing it.

Typically I use taps for all things less than 3/4" and thread mills for all things over 3/4" and thread mills for everything that is OD (obviously).


Also I almost NEVER use Solid thread mills as I don't like all the tears when something stupid happens....and in all my years machining have never destroyed a Indexable thread milling holder. (lucky I guess)

[Eurisko]

Thread milling allows you to do things that are impossible to do with a tap.

Get 100% depth of thread.

Get a full, perfect thread within 1 pitch of the bottom of a hole.

Use the same tool for left-hand or right-hand threads.

Use the same tool for internal and external threads.

Use the same tool for different pitch diameters.

Cut multiple start threads.

Thread large diameters on machines that don't have the horsepower to drive a tap.

That being said, tapping still has its place, too.

You can't thread holes by hand with a thread mill

[dertsap]

tap as big as the machine can handle ,
tapping is far more efficient than threadmilling

[Astonlee]

Tapping is the fastest way of producing threads, so taps should be your first choice, but thread miiling come into their own on shallow holes, large diameter threads, and very difficult to cut materials.

[dynosor]

What about cold forming taps for smaller holes in ductile metals?

[cdlenterprises]

Really depends on what you're doing..material, size, tolerances, etc. For small diameter threads where hole depth isn't critical, nothing is faster than a tap-matic tapping head, especially when using a form tap. For tough materials, large threads, and high accuracy, thread milling is the only way to go. use the same methodology you would use on a lathe - when would you single point cut a thread or when would you use a tap...