Stone removal tool

G’day and Thanks Liza(byzantia); Why didn’t I think of that
bezel-opening tool! I hope you won’t mind if I put in a 1c
addition which doesn’t detract from your light-bulb idea. When
the tool is made, it should be hardened and tempered, but high
carbon steel would have to be used to do that, not car aerial!
So case-harden it. One can buy from engineer’s supply shops a
powder called Kasenit - I am sure you will have it and/or
something similar in your country. You simply heat the tool to
redness, coat it in the powder by dipping then continue to heat.
Repeat this a couple of times, then finally quench the redhot
tool in water, clean it up, resharpen the edge on a stone - and
there you are. In byegone days before Kasenit was invented,
potassium ferrocyanide was used (no, NOT cyanide!) which
despite it’s name is not much more poisonous than most other
chemicals. I remember using that before WW2 when I was Very
Junior! Case hardening can also be done by submerging the tool
in powdered charcoal and heating in a kiln for about an hour,
depending on the thickness of the metal and the depth of
hardened skin wanted. Cheers

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At sunny Nelson NZ where the flowers that bloom in the spring tra la
have nothing to do with the case (hardening.)

John - in the US the material to use is called DRILL ROD, it is
purchased annealed and can be hammered out and finished. Then
heat treat by heating the last inch or so to an orange heat and
drop it into water. Then the tool must be polished at the end
and annealed, by heating about 3/4" below the tip with a soft
flame until the the tip just gets a bluish cast (not dark blue)
quench quickly into water. The fine edge should be hard enough to
do the job with out chipping. You can buy drill rod in any large
hardware store, industrial hardware, or machine shop supply
house, and the correct size would be about 3/16" and a three foot
piece would cost about $3. John Burton, Mech. Eng.

I have purchased “piano wire” at hobby shops. This material was
hard and it came in about 3 foot lengths of various diameters. It
should be suitable for this purpose. Lee