"robgraham" wrote in message ...
I'm making a 50mm long aluminium sleeve for a 12mm steel shaft; it is
just a support sleeve, no rotary motion. I've reamed the Al. out to
the 12mm required and tried fitting the steel shaft. It went in fine,
but I suspect it's picked up a little flake of the Al as I went to
withdraw it and has stuck fast.

Do I heat it to assist removal or deep-freeze it ?

The second bush is fine with the same reamer setting, but I made sure
there was no debris lying around on the trial fit with an identical
bit of steel.

Thanks
Rob
http://www.engineeringtoolbox.com/li...ents-d_95.html

Looks like aluminium expands twice as much as steel, and as the ally
is on the outside, you need to heat it.

--
Graham.

%Profound_observation%