On Apr 20, 16:04, Chuck McManis wrote:
> I'm not sure I parsed this. At my local hardware store the nuts were made
> of Zinc (not steel) and but the washers were made of "soft iron" which I
> thought meant there was a _lower_ carbon content than "steel" washers.
(The
> washers are designed to be compliant whereas the nuts are quite hard)
Zinc isn't a hard metal and it's only weakly ferromagnetic (doesn't stick
to a magnet). The nuts you found are zinc-plated steel, probably what we
call BZP (bright zinc plated). Soft iron sometimes has quite a high carbon
content, and a very variable silicon content (which affects its magnetic
permeability). The composition of "soft iron" varies quite a lot, whereas
although different types of steel have different compositions, the
composition of any given type is fairly standard (and in some cases very
precisely controlled), and usually quite low in silicon.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Wed Apr 21 1999 - 01:51:40 BST