# Milling Titanium



## dragos28 (Jul 18, 2016)

Hey guys, so I've been making dice lately. I'm an avid backgammon player and i enjoy the small (10mm~8mm) heavy dice as they roll better.

so far i've made dice from cow bone, elk antler, aluminum, brass. 
then i decided to buy a rectangular bar of titanium, i cut a small piece (11.5mm) off in my bandsaw and i noticed it needed a lot of lubrication and it smoked up quite a bit.

i put it on my mill and just barely touched it with the endmill and instantly it started smoking up. i sprayed it with lubrication and it barely wants to move. I'm using a 4 flute carbide endmill.

i'm kind of afraid to mill it, at least until i know that its safe.

are there any techniques i need to be aware of?


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## CraigB1960 (Jul 19, 2016)

What kind of titanium did you buy?   CP4 or 6Al-4V, which is an alloy?  I have only milled titanium a couple of times, but did not find it too bad with the right end mill.  I purchased a Niagara Cutter end mill, made specifically for titanium.

I used their STR440 series (3/8") and used it on 6AL-4V.

This is their material/tool selector.

Here's their feed and speed info.


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## JimDawson (Jul 19, 2016)

Thanks for posting that Craig


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## CraigB1960 (Jul 19, 2016)

I went out and looked for a video on machining titanium and found a series from Jim McPherson.  He discusses the end mills he used as well as another series showing an AR15 receiver machined out of 6Al-4V.  I found it interesting.


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## dragos28 (Jul 19, 2016)

It's 6al-4v


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## dragos28 (Jul 19, 2016)

So I'm reading that I need to slow down the end mill speed.


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## CraigB1960 (Jul 19, 2016)

dragos28 said:


> So I'm reading that I need to slow down the end mill speed.


It's good you have 6AL-4V, it machines well.  Well, don't know what speed you were milling at, but three things to look for: Correct type end mill, speed, and feed.  Can alway slow down speed and feed from recommendation....which is what I do.  I'm not on a production line.

Is the carbon end mill you have ALTIN coated?


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## dragos28 (Jul 20, 2016)

CraigB1960 said:


> It's good you have 6AL-4V, it machines well.  Well, don't know what speed you were milling at, but three things to look for: Correct type end mill, speed, and feed.  Can alway slow down speed and feed from recommendation....which is what I do.  I'm not on a production line.
> 
> Is the carbon end mill you have ALTIN coated?



you know, i'm not sure. probably not. i bought the endmill set as part of a package from LMS


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## Jimsehr (Jul 20, 2016)

I don't think it's a big problem but I have had fires start up running that material. 
Jimsehr
Be safe.


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## dragos28 (Jul 21, 2016)

i'm just not able to cut it.
I'm running a slitting saw and i'm trying to cut off a 8mm chunk, i just cant get it to cut through. it smokes and throws sparks but i cant get more than a few mm without it seeming like it's going to break or something bad is about to happen.

i spray lubrication on it but it just doesnt want to go....


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## CraigB1960 (Jul 21, 2016)

dragos28 said:


> i'm just not able to cut it.
> I'm running a slitting saw and i'm trying to cut off a 8mm chunk, i just cant get it to cut through. it smokes and throws sparks but i cant get more than a few mm without it seeming like it's going to break or something bad is about to happen.
> 
> i spray lubrication on it but it just doesnt want to go....



Have to have a tool made for the job.  If you look at the video I posted, the guy is not even using lubricate.  If the tool is not coated with ALTIN or ALCrN then it will just smoke and burn up your tool.


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## mmcmdl (Jul 22, 2016)

Jimsehr said:


> I don't think it's a big problem but I have had fires start up running that material.
> Jimsehr
> Be safe.



While rummaging (sp) thru my junk drawers the other day I came across an old unfinished project from 27 years ago . I had made some titanium valve cover custom nuts for my 70 Corvette motor . I turned them on a Makino cnc lathe with not much problem and drilled for a 1/4-20 tapped hole . When it came to the tapping , NO WAY ! I was in a model shop with any kind of top rated tools available , but still , I couldn't tap this stuff . Not sure of the grade or tensile strength but it was tougher than a $2 steak ! My solution was to drill a 3/8" hole and press some 303 stainless plugs into it and tap that 1/4-20 hole . It worked just fine although I never finished them all . They are as shiney and bright as the day they were turned to this day .

As Jim stated above , Titanium will " light up " just like Magnesium if not careful . One of my old time bosses was taking very light skim cuts on an engine lathe and lit it up in the chuck . I never saw Ed move as fast as he did that day . LOL , God rest his soul .


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## dragos28 (Jul 22, 2016)

CraigB1960 said:


> Have to have a tool made for the job.  If you look at the video I posted, the guy is not even using lubricate.  If the tool is not coated with ALTIN or ALCrN then it will just smoke and burn up your tool.


I'll order some altin coated end mills


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## Tony Wells (Jul 22, 2016)

The key is high chipload and fairly low surface speed. Ti alloys work harden in the blink of an eye. Coated tools will outlast non coated, but unless you need the speed increase (modest though it is) they offer, use cobalt tooling.


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