HELP! I need advice for turning Titanium.

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More4dan

More4dan

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Joined
Mar 17, 2016
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Katy, TX
I'm getting ready to make a new version of my daily carry pen. This time out of Titanium instead of aluminum. Any recommendations for carbide inserts that work for this material or should I use HSS? Open to any suggestions for turning, drilling, and threading.

Thanks!
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I'm not an engineer or chemist, but from my understanding, HSS will not scratch titanium's hardness. At a wedding last weekend in MA, I talked with a retired machinist/welder from E. TX, and he talked briefly about welding titanium and the difficulties that had to be overcome. He mentioned briefly the machining part said something along the lines that tungsten-carbide inserts didn't work well on Titanium. Since it was a wedding (my granddaughter and his grandson) the conversations were short but many, so I didn't get beyond that little bit.

I am interested in what the answer is.

BTW, Good to see you again. I haven't seen many posts by you in a while.
 
Can't help with the machining but I know cutting 1mm titanium wire (CP1) with a saw was a PIA. A blade would go from sharp to dull in 1 revolution even with a flood of very low viscosity fluid. Saw blade options were limited to HSS but I had a dozen M2 blades made and did not offer any significant difference.

Can't wait to see the finished pen.

Is Bruce Boone (btboone) still around?
 
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One of the machinists I work with works a lot with titanium and he's also a penmaker. He's out this week, but I'll ask him next Monday and report back here if he has any sage advice.
 
My recommendation is...don't.

Hobby machines just aren't big enough, it takes a lot on mass to machine titanium, the machine has to be very rigid. You'll also need a lot of flood coolant and most hobby machines don't have coolant pumps. Also, the cutting inserts are very expensive and will dull VERY quickly if the machine is too small and not enough coolant is used.

Sandvik Coromant

www.sandvik.coromant.com www.sandvik.coromant.com

Try stainless steel, much friendlier to turn.
 
leehljp said:
I'm not an engineer or chemist, but from my understanding, HSS will not scratch titanium's hardness. At a wedding last weekend in MA, I talked with a retired machinist/welder from E. TX, and he talked briefly about welding titanium and the difficulties that had to be overcome. He mentioned briefly the machining part said something along the lines that tungsten-carbide inserts didn't work well on Titanium. Since it was a wedding (my granddaughter and his grandson) the conversations were short but many, so I didn't get beyond that little bit.

I am interested in what the answer is.

BTW, Good to see you again. I haven't seen many posts by you in a while.
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When they dropped the mobile app it made it more difficult to participate. I would usually get online during the bus ride commute. I also got busy with a new mill in my shop and started making knives again. Hopefully this little project will get me making pens again.
 
rherrell said:
My recommendation is...don't.

Hobby machines just aren't big enough, it takes a lot on mass to machine titanium, the machine has to be very rigid. You'll also need a lot of flood coolant and most hobby machines don't have coolant pumps. Also, the cutting inserts are very expensive and will dull VERY quickly if the machine is too small and not enough coolant is used.

Sandvik Coromant

www.sandvik.coromant.com www.sandvik.coromant.com

Try stainless steel, much friendlier to turn.
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That just feels like a challenge now. 😃. I've been successful turning stainless Damascus, tool steels, and copper. We will find out soon. Then I'll let you tell me "I told you so". I am worried about threading. When tapping in titanium sheet, I've had to use a forming die to keep from breaking taps. I really don't want to lose me JOWO nib tap.
 
I spent about ten years making jewelry from 316 stainless and 6/4 titanium on CNC and manual machines. I also almost set my house on fire cutting titanium on a hobby lathe in my bedroom.

Titanium, like 316, work hardens quickly and easily. It does not suffer dull tooling. Unless you have horsepower, you want to use sharp, positive rake cutters. Titanium also doesn't give up heat easily and the heat will build up in the part instead of leaving with the chips. That's why flood coolant is almost always recommended. All of that said, I almost always had good luck with PTD brand cobalt high speed steel drill bits. They absolutely have to be started on center. If you don't spot drill, the drill likely won't last one hole. Small pecks to clear chips and add cutting fluid will be necessary. Do not try to follow a drill with a larger drill. Drill on size or bore or ream, if you follow it with a larger drill that drill will burn. Sharp, positive rake, carbide inserts work well on lighter machines. TiAlN coatings or other similar material specific coatings will greatly improve tool performance and life. Fine chips are a fire hazard and cutting titanium can create sparks easily. (The kids used to think I was hazing them when I said the chips would go up in a tower of white flames if they didn't keep their machines clean. Got to the point that I'd take the new guys outside with a bucket of chips and fire extinguisher and set a pile of chips on fire with my cigarette lighter. It's bright white and hot, but any ABC extinguisher should put it out. It's not as bad as magnesium alloys.)

So, all of that said, I don't find it hard to work with even on a hobby lathe, but there's a learning curve and you need to be cautious particularly of the fire risk.
 
I forgot a VERY important point...the titanium I was talking about is pure titanium which is next to impossible to machine on a hobby lathe. I forgot to mention titanium ALLOYS, which are doable on a small lathe. I believe titanium grades 1-4 are pretty much pure while grades 5 and above are alloys. Pick one of the alloys and you should be fine.
 
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