Free cutting aluminium?

I've been using aluminium for years.

Today I used a piece that I bought from a seller on ebay, it's supposed to be 6082.

When turned it cuts into small chips and powder.

Any idea what it is? I've never seen aluminium like this before.

The chances of it being 6082 are probably zero; it is more likely to be ex-saucepan!

Andrew

Don't get it too hot, or else! 🚒

Bri

That's a rough old finish too. Are you going fast enough

Looks like cast Ali to me, is your tip for Ali?

Steve

Hi Chris,

It may be a Pb - Bi alloyed free cutting aluminium. Newer free cutting alloys may have Sn - Bi or just Bi to avoid lead.

Thor

Looking at the way it machines my money is on a 2000 series aluminium probably 2024, but not 6082 as I have machined lots of 6082, swarf without a chip breaker comes off in a spiral.

What size 6082 do you need as I probably have a piece for the cost of postage.

Bob

This was a 250mm bar, the ends were sawn so I think it came from a longer bar.

The ends of extruded bars are sometimes discarded and not used, likely your Ebay supplier has been able to get these off cuts and now you are having problems. I have often found similar effect on stock bar I have bought and now cut off the first 2 to 3 inches. Maybe some one else has had this happen. Also I sometimes find that just under the skin, about 3 mm in a hard layer which does not machine well.

Clive

Possibly then.

I'll put it in some caustic soda tomorrow and see what the smut is like.

100% not 6082 that comes off continuous until broken up, I use it daily for best anodising and strength ratio.

Free machining comes off exactly like pictured whether that's 2011T6 or 6262T6 no idea. Fine cut on after picky above will come off like chrome. Heavy cut with coolant and right tips can come off satin.
Generally whatever the depth of cut ie 4mm chips tends to break up squarish 4x4mm. Lovely to work with does save time machining with no clogging or tip build up. The other reason don't use for daily work is it doubles the material cost at expense off clawing back around 15 mins on a 3hr job.

Production or small batch work I wouldn't hesitate to use 2011T6 (T6 being harder)

Thanks.

6061 & 6063 anodise the best but 6082 is very good

The chips are fairly square on these, no matter the cut depth - your right!

EDIT: just seen you said strength / anodising ratio for 6082 - so your right!