Machining Alloy 260 Brass

Alloy 260 is extremely nasty gummy stuff to machine.

Carbide is not needed and and probably counter productive. It needs tooling with very high back rake and light cuts.

If all you need is an inch and an eighth of tube, email me with you're snail mail address and I'll mail you some. I'm not sure of the alloy, it is probably 260 or 353. 7/8" od .019 or 020 wall. It is a standard tubing in the lamp industry.

You don't say if you are tapering it up or down, either way, it'll stretch just fine.

Paul K. Dickman

It machines very nicely.

How important is the OD? If the depth isn't too great, you can produce a

0.018" wall with a good setup, but you might have an unacceptable OD variance in the raw stock.

It's hard (G) to say; the difficulty will depend heavily on how long the part is. If the length is much bigger than the diameter, it will be a challenge. The setup needs to be rigid, and the outside will need to be well supported. I would suggest using soft jaws, bored to fit the tube.

I would use HSS for a better finish.

I seriously doubt it will crack. You'll need to experiment to find out for sure. You *might* need to anneal the material before forming, as it will work-harden somewhat during machining. I don't see how you can form a taper without stretching (or compressing) the material, though.

You might also consider machining the part to the finish dimensions.

Jim

Whoops! Brain cramp. I hallucinated that he was asking about 360. My bad.

260 is almost as bad as pure copper.

Sorry,

Jim

Whoops! Brain cramp. I hallucinated that the OP was asking about alloy 360. Alloy 260 is a bear to machine.

Sorry,

Jim