working with Titanium

[mr fixit]

Just read Fishmans thread about his Ti can.

Last night I started a new can and turned gr5 Ti for the first time on my 12" Logan. I have been pretty apprehensive about trying to turn any titanium after hearing lots of people talk about it. Truth is, it was great! It turned almost as easy as 17-4 which I was able to cut like butter. It was much better than 4130.

I have a set of insert tooling that takes CCMT and CCGT carbide inserts. I didn't have any specifically for Ti, but I have had some on order for a while. The inserts I have are rated for carbon steel and really didn't do a good job at all. Just for grins I tried a CCGT insert I have for aluminum and it was wonderful. Cut great, with nice shiny surface finish. It did have long stringy chips though but nothing that couldn't be handled.

I am also simultaneously working on a purge chamber for welding titanium in.

This can will probably be titanium tube and end caps with 17-4 baffles, 1.625" OD, direct thread and about 7" for a 16"AR.

[mr fixit]

Also, for what its worth, I was able to take up to .040" depth of cut (taking .080" off diameter) with the CCGT inserts. Still had a nice finish. Speed was about 200 sfm.

[fishman]

I never have any issues with sharp carbide, even with the cheap stuff. When grinding my own HSS tools, I use very little end and side relief, about 5°. And I use 0° back rake and side rake angle. A small nose radius.

The only difficulty I run into is drilling. Sharp cobalt drills help. Through coolant and a more powerful lathe would help even more.

[garredondojr]

Cool information! glad you had good results.

I was going to try Ti my first go around but got a little gunshy and didn't really have the money to buy more bar if I did screw up so I opted for carbon steels this go around 4340(baffles) and 4130 tube/endcaps.

Were you using coolant? When I asked for guidance on Ti many recommended that heavy cuts with fast feed was actually beneficial as it kept the heat in the chip and not the work piece which looks like what you did.

Oh one last thing where are the pics?

[fishman]

Were you using coolant? When I asked for guidance on Ti many recommended that heavy cuts with fast feed was actually beneficial as it kept the heat in the chip and not the work piece which looks like what you did.

I only use coolant when drilling. A fast feed rate is recommended. If you aren't using continuous coolant, cut slow. I only turn at 300 RPM

[mr fixit]

Cool information! glad you had good results.

I was going to try Ti my first go around but got a little gunshy and didn't really have the money to buy more bar if I did screw up so I opted for carbon steels this go around 4340(baffles) and 4130 tube/endcaps.

Were you using coolant? When I asked for guidance on Ti many recommended that heavy cuts with fast feed was actually beneficial as it kept the heat in the chip and not the work piece which looks like what you did.

Oh one last thing where are the pics?

I drilled a .375 hole in the center with HSS bit turning the work at 250 rpm. I have a turret lathe and cranked pretty good, pretty heavy/fast drilling. I used a small pump can of 30w oil as coolant and drilled about .250" then pull back and clear chips then repeat.

[ECCO Machine]

Last night I started a new can and turned gr5 Ti for the first time on my 12" Logan. I have been pretty apprehensive about trying to turn any titanium after hearing lots of people talk about it. Truth is, it was great! It turned almost as easy as 17-4 which I was able to cut like butter. It was much better than 4130.

Ti isn't bad at all for normal lathe turning operations. Where you run into difficulty is drilling deep holes, tapping holes or trying to mill slots where the cutter is working full diameter. Ti has extremely low thermal conductivity, so tooling heats up quickly. It's also a very "springy" metal, which is why deep drilling and (especially) tapping are a challenge.

[mr fixit]

Last night I started a new can and turned gr5 Ti for the first time on my 12" Logan. I have been pretty apprehensive about trying to turn any titanium after hearing lots of people talk about it. Truth is, it was great! It turned almost as easy as 17-4 which I was able to cut like butter. It was much better than 4130.

Ti isn't bad at all for normal lathe turning operations. Where you run into difficulty is drilling deep holes, tapping holes or trying to mill slots where the cutter is working full diameter. Ti has extremely low thermal conductivity, so tooling heats up quickly. It's also a very "springy" metal, which is why deep drilling and (especially) tapping are a challenge.

How is it single point threading?

[ECCO Machine]

How is it single point threading?

Pretty easy with carbide inserts. A bit of deflection, especially on smaller IDs with thinner bars. If your threads are long, you may have to creep deeper as you go further into the bore.