Newsgroups: rec.crafts.metalworking
Subject: Re: Machining Teflon:My $0.02
From: jmorton@euler.Berkeley.EDU (John Morton)
Date: 7 Sep 1994 22:24:10 GMT

In article <34jhuk$2n4f@ns1.CC.Lehigh.EDU>,
JOSEPH A. ZELINSKI <jaz0@ns1.CC.Lehigh.EDU> wrote:
>     Over the course of many years machining experience with Teflon, I must
>   concur with previous posters on several key points..
>   [several key points]

I guess I agree with all that, especially the part about a good grind
on the tool.

But the thing I have observed more than anything about Teflon
is that it is unevenly stressed throughout it's volume, which
means that as you remove material it wants to take on another
shape.  The usual ploy for dealing with that situation is to
relax and reclamp the part very lightly before the final cut.  
The difficulty here with Teflon is that the stuff is too
slippery to clamp lightly.  I usually try to use a method that
provides full containment but very light pressure, e.g. soft
jaws on the lathe or side-pressure clamps on the mill table.

John Morton					University of California
jmorton@euler.berkeley.edu			Mechanical Engineering
{decvax,cbosgd}!ucbvax!euler!jmorton		Machine Shop