Date: Wed, 08 Sep 2004 12:53:29 GMT From: Bob <nopenospamlmakingupaddresses.com> Subject: Re: Oil plug gasket..
On Tue, 07 Sep 2004 14:06:36 GMT, amesnospamrak.demon.co.uk (Andrew Stephenson) wrote: >In article <pq9rj0h2uvgnpfm0qhjkt2oojp3cj5qiv1nospamcom> > nopenospamlmakingupaddresses.com "Bob" writes: > >> SO you're saying that the copper gets hardened through the >> heating and cooling cycles of the engine running? I've always >> wondered about these things... I thought we changed them due to >> scratching during tightening. But, I was just guessing. > >Just in case this doesn't get said... Vibration and generalised >"working" (ie, mechanical flexing) of the copper will harden it. >Some of this will come from temperature cycling; but don't forget >how much vibration happens during everyday operation. > >Work-hardening, I was once told, is why chains used for carrying >loads should be annealed (put through a softening heat treatment) >at intervals, to stop them getting too brittle. Interesting. I knew you could harden copper this way but I never thought of general vibration as being enough to do the job. Makes sense through.