Logan Oplinger on mon 7 apr 03
Acquire an old car radio antenna. The innermost segment (top) is solid
stainless rod with a moderate hard temper. The diameter is about 3/32"
Remove knob from top, and push the innermost segment out through the
bottom, or just cut 3-1/2 to 4 inches off the top from which to make the
needle.
To increase the hardness of the needle, the piece of rod can be work
hardend by hammering it on an anvil holding one end in a pair of ViceGrip
(c) pliers. Uniformly hammer the entire length of rod except the end held
in the ViceGrips. Rotate the rod while hammering, and do not allow the rod
to bend. About 1-2 minutes of hammering is adequate.
To form the needle, using either an electric bench grinding wheel (fine) or
a good hand file, grind or file the rod into a long tappered needle. If
grinding, finish the needle with a hand file, and then finer grades of
sandpaper.
A needle made this way will have some spring to it, and will bend if over
stressed, but not break or snap off like needles made of hard tempered
carbon steel. It also will not rust.
The handle can be made of any suitable material (bamboo, hardwood, metal,
ceramic or plastic).
Logan Oplinger
Another Pacific Island
13.28 N. Lat., 144.45 E. Long.
Maurice Weitman on mon 7 apr 03
Thanks for the hint/tutorial, Logan.
Two questions:
When hammering the antenna rod, won't it become asymmetrical and
therefore weakened at the thinner spots?
And can other stainless pieces (flatware, etc.) be worked (hammered
and/or grinded/ground??) without damaging their stainless properties?
I've often been tempted to grind some stainless pieces but have been
afraid to damage them.
Thanks again.
Regards,
Maurice
Logan Oplinger on tue 8 apr 03
Hello Maurice,
On Mon, 7 Apr 2003 11:34:45 -0700, Maurice Weitman wrote:
>Two questions:
>
>When hammering the antenna rod, won't it become asymmetrical and
>therefore weakened at the thinner spots?
The antenna rod is relatively hard to begin with, so hammering with only
moderate force (like pounding a nail) will not distort the rod
appreciably. Also, rotating the rod while hammering, and hammering along
the entire length will help insure that no excessive ammount of hammering
is applied to only one location on the rod.
>And can other stainless pieces (flatware, etc.) be worked (hammered
>and/or grinded/ground??) without damaging their stainless properties?
I have not tried ordinary SS flatware, but I suspect that if the
composition of the metal is right, you should be able to work harden
flatware. If I recall correctly, I read somewhere that part of the
manufacturing processes of stamping and forming impart workhardening to the
metal which is utilized to increase the strength of the finished article.
I would not be tempted to do this with good SS knives though, because they
are hardened and tempered in a manner somewhat like ordinary high carbon
steel. It would be necessary first to heat the SS to soften it so that it
could be worked, and then heat treated again to impart the desired
hardness/temper to the metal.
>I've often been tempted to grind some stainless pieces but have been
>afraid to damage them.
Careful grinding to avoid overheating and destroying the temper is not a
problem if you need to remove excess metal.
For more information, the following web site may be useful:
http://www.azom.com/details.asp?articleID=972
I found this site doing a search through Google, on the
words "knives", "tempering", and "stainless". There are many other sites
as well that offer more detailed information. You might also include "work
hardening" as a search words.
Logan
sugilac on wed 9 apr 03
Go to a bike shop and ask for scrap stainless bicycle spokes. These
are drawn to finished diameter, hardening them up a bit, are
springy, and if cut to a 4" length and the burr filed smooth, can be
chucked in an electric drill and ground to a point on any hard
brick, block of concrete, chunk of silicon carbide kiln shelf that
is handy. If you point both ends you can drill a hole in a hardwood
dowel or oak tree branch from the yard, dab a bit of epoxy in if you
are worried about it coming loose, and drive it back into the hole.
A great potter's party favor.
Bob.
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