Sticky ally

I've just chucked a length of 30mm dia. "ally" to see if a newly hand ground drill was cutting OK. The stuff came out of a job lot of material so is unidentifiable. It was like trying to drill sticky toffee. Horrible stuff!

Tried turning it and same thing. Finally tried to part a piece of and the parting tool kept getting stuck and stalling the motor.

It looks like any other decent bit of tool grade ally, rolled rather than cast. I have never come across anything as soft and squidgy as this before - what is it?

Rik

I assume you are referring to Aluminium if so try some lubrication either paraffin or WD40 works quite well as even 6082 alloy can cause a build up on the tool tip and thus not cut and can break tooling.

Sounds like fairly pure Aluminium, rather than one of the hard alloys.

... Horrible stuff to work.

MichaelG.

Hi

I have got a lump of that stuff somewhere. It doesn't seem to cut but rather tears/smears irrespective of how sharp the tool is or whether lubricant is used. Wasn't impressed with it so it got put in the 'try it later bin'.

Cheers

Martin

Edited By Martin W on 30/04/2014 11:30:29

You have some cheap pure aluminium.

To machine it keep it wet with suds, paraffin or WD40, 20-30° rake on the tool and slow revs.

Alternatively, bin and buy some 6082 or 6063 grade. Always check that the material is what you asked for as it is impossible to tell a grade of aluminium by looking at it. Been caught out a few times in the past.

Trev

Hello Rik,

Many years ago I made the mistake of trying to join perfectly good aluminium parts by the then novel method of aluminium soldering. The joints made but the job was impossible to machine afterwards having lost all it age hardened properties in the heating process; as in your case it was like machining toffee.

If you haven't binned it shove it in the freezer to see what effect that has, it might be an interesting experiment.

Regards

Brian

I was given some 4" dia billets of aluminium a few years ago, it too was hopeless to machine.

It turned out that it had come from a place that made divers oxygen cylinders using the deep drawing method.

Obviously the properties for drawing and machining are not compatible.

Phil