Thread Milling

[Lars Christensen]

Boss man:

Lars we are getting a job, that have some tapped holes, I don’t know look like 1-1/2, but they might be metric. We got to look at it when the job comes, but I was thinking of getting some taps, then we can always start it in the CNC and then tap them by hand.

Lars:

Sound like a job for thread milling.

Boss man:

Ok, but we have limited money for tooling, have you ever tread milled before?

Lars:

Nope

Boss man:

Ok, well go for it, take the shop to that level.

 

So Lars went home and has now been reading old topics on thread milling the last 2 hours (yawn).

Thank you to all, I now feel very in lighted in the topic, bottom to top and top to bottom.

 

So now I am looking to by something to do this thread milling with, do anyone know a good tool that might has some variety in size, and what is the holes size were you prefer to start using thread milling instead of tapping.

 

I am normaly running tap sizes from 1/4 to 1/2.

 

Thanks

Lars

[Metalmuncher]

Try Emuge Very good cutters with long life and do a great job.I thread mill most of my holes.The thing with Emuge is their price but you get what you pay for

[crazy^millman]

Hum let me see there is this guy I know I think he has Tool or something like Fab in the name. Then again I think if it was Fab or Tool then it might be that guy who makes his living off of making Tools that are used to Fab a part that would be cool in that Tool guy could Fab you soemthing up. It might require the right Tool for the Job but if you have a Faboulis realtionship with him it Might get the Tool and Fabloiuse delivery and Still allow that Guy Fabtool or ToolFAB to get some business and be rewarded for the help he gives so many on here just a thought.

 

I think ToolFab might be a good choice but I could I would also get my tools from Toolfab but to think about good Tools then Toolfab might be the person to look up.

 

 

HTH

[M. Anderson]

As Ron says - turn-a-bout is fair play

 

ToolFab

 

and

 

Schmarje Tool Company

 

Just too help you find it!

 

Later,

 

Mark

[Lars Christensen]

Thank you gentelmen,

I will try to get a catalogue from Emuge, and ToolFab should already have been number one contender on my list, my bad for not thinking in the direction to be able to send work to a fellow forum member. Sorry ToolFab. I will properly contact you in the following week.

 

Lars

[Tom Szelag]

Interesting. All those thread mills have multiple flutes, bunch of threading points, and only one thread pitch to them.

 

Watching our senior machinist do some work earlier this semester, he used a much different thread mill. Has two cutting points offset 180 degrees (I imagine so its balanced when its spinning at thousands of RPM). Just big enough to do 12 threads per inch, but since its only two cutting points you can use it for a variety of stuff, for example I think we've done between 32 and 12 thread per inch screws. All the hardware we make uses class 2 threads, and they work fine.

 

Seems like that kind of tool would be more logical as you can use it for a wide range of diameters and screw pitches.

[mrainey]

A multi-fluted thread mill with lots of teeth is limited to a single thread pitch. But, you can usually thread a hole with it in one or two helical interpolations - very fast. The internal threading bar will do any pitch, but requires an interpolation for each thread in the hole - usually much slower.

 

For production work, you definitely want the dedicated, multi-flute, multi-tooth cutter. For small-diameter, relatively deep holes in tougher materials, I think tapping is usually better. Remember that with a thread mill, you have pushoff and chatter to contend with, which can cause finish, size, and tool life problems.

[Chris Rizzo]

Lars,

 

You'll probably find the single point thread mill tool a fair amount cheaper than a multi-tooth dedicated cutter, and also has the flexibilty to do a wide range of pitches with the same tool...while multi-tooths are ground for a particular pitch, more $$$, and way faster.

 

You and boss-man will have to look at the cost of a multi-flute tool in relation to how many holes this job entails.

 

good luck.

[Toolfab]

Wow and I just saw this thread now.....sorry for getting here late. Thanks for the props guys I appreciate it.

 

Lars how many holes you need to do? What is the material? What is the length of cut?

 

Thread milling is a great time saving cost reduction tool if used in the right application. There have been good points on both sides of the issue here.

 

The point that a thread mill is limited because it is ground to a certian pitch is valid. You have to look at the options tho.

 

A .375 diameter 20 pitch thread mill can create any 20 pitch hole over 7/16 with in reason. 7/16,1/2, and so on. Thread mills start at the bottom and cut your pitch in one revolution were as a single point threading tool would need to make 20 revolutions to create a 20 pitch hole of 1. depth.

 

I would be more than happy to help you out. Just let me know.

 

and thanks again guys.

[Tim Johnson]

If you're looking for a thread mill for a 1 1/2? dia thread you should look for an indexable thread mill. (don't know if ToolFab carries this, if so it should be just fine). I use Kennametal, Carboly and Advent myself. All work just fine. If you use a certain name or have a favorite rep to work with, they should be able to provide you one.

With an indexable thread mill you just need to buy different insert for each thread pitch you might use.

[Lars Christensen]

Thanks for all the help.

They material is some kind of stainless, something 2206 something, block was previous made in Italy. There is about 20 holes and they are about 3” deep. I did not have any time to look into today, to busy doing some post work.

 

But there is another day tomorrow

 

Lars