Friction welding

[Conspicuous]

Hello all
Just out of curiosity, is friction welding useful for airguns and if so can you do it with a lathe!

[Big Bore Bart]

 Well it depends on which type of airgun.  It could be used to make springer tubes and pistons.      As far as doing it with a lathe, not with the hobby size most of us have.    My lathe is an old atlas 10" and I know it would not be enough.

[Wheelchair Bob]

Friction welding requires a fairly large lathe and considerable horse power to complete successfully.  While it is surely possible I would prefer to TIG weld and machine to fit which will result in a much stronger bond which will be completely air tight.  Friction welding rarely yields a super high quality weld which also requires a lot of machining to correct any misalignment or warping from the heat.  Just .02 from a former Machinist and Welder by trade.

Wheelchair Bob

[jvanschoonhoven]

I believe they friction weld axles for trucks and it's a solid weld and every bit as strong as tig you can weld dissimilar steels with friction welding that would be almost impossible with other welding methods. Also if your steel is heat treated already friction welding heats up a smaller area keeping the metal grain smaller around the weld.

Having said that I really have no idea what part of an airgun would benefit from friction welding.
I saw a guy friction weld an end mill bit to 4140 steel cause the mill was running backwards and 3 times the speed it should have been and the carbide end mill was welded solid to the work pice.

There is a lot to learn to do it properly so if your willing to take the time and have a big enough lath it is possible to make very nice joints.

[Big Bore Bart]

  I have friction welded SS to Carbon steel, and SS ends to SS tube.      The thing is I was using a 7.5HP 16"x60" lathe to do it, and you have to stall the lathe to get a proper weld.