Parting thin wall titanium tubing

Not really a gunsmithing project but thought I would post it here because I suspect some of you deal with thin wall titanium in suppressor manufacture, etc.

I have a customer who has asked if I can "cut" some titanium for him. When I asked him to explain, I realized what he really needs is a tube parted into several pieces. The tube is grade 5 with wall thickness of about 0.010 (don't have measuring tools handy.)

1) I have a Seco insert parting tool. I have hundreds of inserts I bought at a tool sale. They are new but not in packaged and I can't figure out the types from the few markings they have. I'm gonna guess none are designed for titanium but I'm going to see if they will cut it. Even if I only get 1 cut per insert, I'm better off than buying new (I have about $0.03 invested per insert). Any reason to think they wont cut it?

2) when I work with thin walled Aluminum or steel, I turn a wooden rod to slip fit inside to keep from distorting the tube from the force of the chuck jaws. I'm afraid to use wood with titanium for fear the heat generated will spark the wood. Would it be ok to use steel, aluminum, or bronze or would they cause some type of reaction?

3) I have flood coolant reservoir and pump but don't currently have it hooked up. Think I could get away squirting coolant by squeeze bottle since it is so thin walled?

Any other advice about things I may encounter but haven't thought of?

By the way, lathe is 13" 5hp. I think I'll have enough power and rigidity.

1. Grind a high speed parting tool as narrow as possible, like .010". This will keep your tool pressure down. Run slowly and feed fairly briskly.
2. Hold it in pie jaws. You are not going to make any significant amount of heat but your method will deform the tube.
3. The cut should be done before you could squirt it.
Get to work.

Set up your Dremel Moto tool with a cut off abrasive wheel on the tool rest of any lathe. The thin wall tubing can be held with the lightest of jaw pressure.

Cut to your heart's content with no worries, and little burr.

At that wall thickness, even if the cut wheel does not approach the work at 90 degrees, there is little to be lost.

Enjoy!

Use a treading tool when the tube is so thin. I think a wooden plug makes a lot of sense and a 6 jaw chuck if you have one.

CalG said:

Set up your Dremel Moto tool with a cut off abrasive wheel on the tool rest of any lathe. The thin wall tubing can be held with the lightest of jaw pressure.

Cut to your heart's content with no worries, and little burr.

At that wall thickness, even if the cut wheel does not approach the work at 90 degrees, there is little to be lost.

Enjoy!

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I was looking at the lathe last night thinking this might be a good excuse to build a dremel mount for the toolpost... a lot less loss per cut for sure.

steve-l said:

Use a treading tool when the tube is so thin. I think a wooden plug makes a lot of sense and a 6 jaw chuck if you have one.

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Threading tool makes sense, a lot less contact area = less pressure on work piece and less heat. I can always face the cuts flat afterward.

Thanks for the suggestion!

steve-l said:

Use a treading tool when the tube is so thin. I think a wooden plug makes a lot of sense and a 6 jaw chuck if you have one.

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Used to make titanium tubes for suppressors, though ours had a little more meat than .010 wall thk. Not a lot more, though. I would recommend this method - works great. My method was to take a long tube and part off many blanks. Each end would be individually bored and threaded afterward, so the end was also faced at that time - the parting finish was moot. So I used whatever tool made the least damage, heh. Threading tool ended up being the first thing I tried that was acceptable.

We cut hypo tubing .008 to .012 wall all the time with a threading tool (small quantities. If we ever did medium quantities. I would use a fishtail cut off. Somma used to sell them, if they do not have them anymore then I would make one. When we do large quantities we do them like this http://www.youtube.com/watch?v=wUeo8UaNSYM .
Your tube might be larger than the stuff we routinely cut, if so and you are using a three jaw and not a collet, I would use a brass or aluminum plug as it would support the tubing better and not allow the 3 jaws to crush it. Coolant or cutting oil would be optional with a threading tool.

I used a three jaw, but I had soft jaws bored to pretty much close on 80% of the circumference, and kept the hydraulic pressure on the chuck turned down pretty low. A plug would have been smarter but I guess I cut corners. I messed with the pressure until it was in a satisfactory place between "deforming the tube" and "still holding it enough to not spin" and just noted the pressure and kept those jaws for that job whenever I ran it.

skelso said:

I'm afraid to use wood with titanium for fear the heat generated will spark the wood.

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Really? Just how hard did you think you were gonna be going on ten thou wall tubing that you were worrying about the heat?

The best advice I have seen here so far is to make a HSS parting tool on the end of a bit blank, and get on with it. Sharp tool, slow speed, and no drama. Ti. cuts nicely until you rub it with a dull tool, then it gets miserable. So. Sharp tool!

If you slide a wood dowel into the tube past the cutting off point, it will support the cut off end and keep it from flopping around. Mainly this will help you keep the thin end of the cut off tool intact as the breakthrough occurs.

Cheers
Trev

trevj said:

Really? Just how hard did you think you were gonna be going on ten thou wall tubing that you were worrying about the heat?

The best advice I have seen here so far is to make a HSS parting tool on the end of a bit blank, and get on with it. Sharp tool, slow speed, and no drama. Ti. cuts nicely until you rub it with a dull tool, then it gets miserable. So. Sharp tool!

If you slide a wood dowel into the tube past the cutting off point, it will support the cut off end and keep it from flopping around. Mainly this will help you keep the thin end of the cut off tool intact as the breakthrough occurs.

Cheers
Trev

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True, guess I wasn't thinking clearly and overestimating how difficult it would be. My only experiences with titanium have been solid bar which created a lot of heat quickly.

skelso said:

True, guess I wasn't thinking clearly and overestimating how difficult it would be. My only experiences with titanium have been solid bar which created a lot of heat quickly.

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Sounds like you were not using a tool that works well with the stuff.

Esp. if you made enough heat that lighting a wood plug on fire is of concern.


My experience with it (which is by no means extensive) has been that a sharp tool, and either a constant feed or get the tool away from the stock, were the two things I needed to keep it working.

Any tool that squeaks, is pulled away from the work NOW! Esp. drills. Lots of misery to be had when a drill welds itself to the inside of your bushing....

I know it can be lit on fire if worked dry. We played with it and found that you really really had to push some very high speeds, and make very fine chips, to get any fireworks at all. In the name of science, yknow!

Low speeds, relatively heavy feeds, at least always cutting or completely off the work, and the stuff is pretty underwhelming to make decent parts from.
I have made a fair pile of hat bushings from 1 inch and 3/4 solid stock, as well as a bunch or rings and the like from salvaged Ti. bolts that were headed for recycle. Used HSS for most, some freehand turning with a hand held tool, along the lines of using a watchmakers graver.

Cheers
Trev

On jobs with a low-enough cycle time that I had to babysit the machine, I'd often take some of the titanium chips, put them on the anvil of my bench vise, and take a flame to them. Preeettyyyyy -shit, now I'm seeing spots everywhere...

Customer brought tube by. Turns out it was actually 0.050 thick wall. Made the first cut with HSS threading tool and it cut easily but left bevel on part so I faced it and cut the next two with a insert parting tool.

Now laughing at myself for being so unsure about cutting it. It cut like butter, no coolant.

skelso said:

Customer brought tube by. Turns out it was actually 0.050 thick wall. Made the first cut with HSS threading tool and it cut easily but left bevel on part so I faced it and cut the next two with a insert parting tool.

Now laughing at myself for being so unsure about cutting it. It cut like butter, no coolant.

View attachment 150109

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Good call on the parting tool - good sharp inserts should do you well for a while with .050 walls.

I often cut thin wall steel and stainless tubing with a pipe cutter. I have three cutters that cover the range of 1/8 to 4" and using very sharp carbide cutting wheels. The cut is leaving a small lip on the inside, if this is interfering with the application, the lip can be de-burred.