Reading ETKA hardware #s

[Larry C Leung]

Hardened bolts are "hardened" by either their alloy or temperate methods.
The process hardens the steel by forcing the crystal lattices into
patterns that allow less ductility, and by default, have less chemically
active sites availible for corrosion. So, hardened bolts will tend to be
more corrosion resistant than mild steel bolts. The opposite would occur
in cast iron bolts. (no, they don't exist, too ductile and brittle
simultaneously (sp?)) They scale and the scale keeps them from rusting,
but, they break the moment any reall torque is applied, and they have
limited tensile strength, but that would work if corrosion was really an
issue. I suppose that some of the aluminum and titanium fasteners used in
the high tech bicycle industry would have similar properties. And if you
think OEM Audi bolts are expensive,  just check out a Campagnolo spare
parts catalog!

LL - NY

On Mon, 08 Oct 2001 16:50:53 -0400 Huw Powell <audi at mediaone.net> writes:
>
>
>Pantelis Giamarellos wrote:
>> 
>> A similar device works with a magnet attached to the extreme point 
>of the
>> telescopic arm. Only works with metalic items attracted by the 
>magnet by
>> most usually bolts and tools are so.
>
>> > > > The second disadvantage - that it's usually austenetic -
>> > > >  and retrieval of stainless bits
>> > > > that fall into the wrong places can be - erm - awkward?
>
>I believe that is called "going full circle" we've finally caught our
>tail, now what are we going to do with it?
>
>To reiterate ad nauseum (wouldn't "reiterate" in mean something like
>"drive the same road again"?), stainless is very nice in high 
>corrosion
>low load situations.  Also well worth the trouble on exhaust systems.
>
>If you're not confident of your "risk taking" abilities, don't use 
>it.
>
>but it sure looks nice in a lot of trivial places, making those 
>places
>incredibly easy to undo in the future.
>
>of course, the "looking nice" is just a bad habit.  the "ease of
>undoing" is the legitimate justification in certain applications.
>
>also, the hardened bolts used in many important locations seem to rust 
>a
>lot slower, if at all, so they aren't such a problem anyway.
>
>-- 
>Huw Powell
>
>http://www.humanspeakers.com/audi/
>
>http://www.humanthoughts.org/