Philip on thu 19 apr 01
Dear Bill,
While I am not 'Clive', and hopefully not a busybody either, I will throw my
Hat in the ring for fun here...
'Files' are Hardened Carbon Steel.
Sufficiently high (Red or Orange) Heat, and then 'quenching' in certain
Steels will result in 'Hardness', or being 'hardened'...
"Temper" is to heat once again, to a lesser temperature, being said to
'draw' the hardness TO a 'temper', and quench.
To Heat a Hard Steel, and allow it to slowly cool, is to soften it, 'anneal'
it, or to entirely draw the Temper.
This is convenient for shapeing say, a 'file' into becomeing something
else...to do so in an annealed state...sometimes called 'dead-soft'.
To 'Harden' it, one may heat it Red, and quench.
Then, heat it again to a lesser heat, as 'straw' color say, and quench it
then.
Oil in a coffee can or similar works fine...it may 'flash' (catch fire, or
the gasses may do so, being generated from the hot metal being plunged into
it...) for a second...no big deal.
There are 'Air' hardening Steels as well, and I do not know anything on
that.
You will have a plenty 'hard' and also fairly 'tough' Steel ('Temper').
"Glass-Hard" or full hard Steel, is a mite brittle for most things.
Some Old 'Scalpels' and certain other Tools were near to this 'Hardness'.
'Spring Steel' is a particular temper, given the more or less correct
'Steel' to do so with.
Many Steels will be amenible to being 'Springy' to some extent, with
approximately the right temper.
Do not confuse so called 'Mild-Steel' with Steel...it will neither 'harden'
nor accept a 'temper'...at least not as is worth mentioning...
Many people have been persuaded to refer to this stuff as 'wrought
Iron'...being used now-a-days for so-called 'Wrought Iron Work', Fences,
Gates and the like.
It is maybe 'figuratively' Wrought Iron, in a way...
But it is NOT 'Wrought Iron'...it is so called 'mild-steel'.
This is also called 'cold-rolled'...'Strap', 'Angle-Iron'(NOT "IRON!)...and
so on.
Old 'hand saw' blades are often a wonderful Steel, springy and fine.
They may be 'cut' in a way, using Tin Snips, though it is more of a
controlled 'crack' than a 'cut'...just as they are.
On and on...!
Files are very nice Steel, and may be made into all kinds of things.
Annealing and hardening and tempering will allow you much less labor and
more controll.
Good Luck!
Phil
l v nev
----- Original Message -----
From: "Bill Amsterlaw"
To:
Sent: Thursday, April 19, 2001 3:50 PM
Subject: Re: Dull tools / Make your own
Hi Clive:
I really know very little about the physical properties of metals. I
observed that the steel that files are made of, when heated orange-hot,
becomes very hard and brittle (ie will break if you drop the tool). I
assumed that this hardness is a desirable feature in that the blade should
hold its edge longer than a softer steel. Maybe this assumption is
incorrect. The trimming tools I have made from this material do seem to
hold an edge for quite a while, but I have not tried to compare them with
other tools. Do you think that spring steel, properly tempered as you
described, would hold an edge equally well? or better? Would the spring
steel be easier to sharpen?
Are metal files brittle because they were heated to a higher temperature
before being quenched ... or is the alloy different from what you call
spring steel? ... or both? If you heat file steel to a dull red before
quenching it, will it be springy and less brittle?
Cheap new or used files seem to be readily available. Can you recommend a
source for spring steel in convenient sizes and amounts?
Bill Amsterlaw
Keene, NY, USA
http://amsterlaw.com
wamster@amsterlaw.com
Clive Tucker wrote:
>spring steel is also good for trimming tools and comes in more readily
>useable sizes. And if you have a blow torch, it makes the whole heating up
>business quite a bit easier. and you have to retemper the metal after
>heating. i.e quench it in water before it cools. different metal
>temperatures before quenching give different hardnesses.bright cherry is
too
>hot and though hard, tool will be brittle. try quenching just as red glow
is
>fading.
>so bend, shape, sharpen, temper, final sharpen.
>or ask a blacksmith.
>Clive Tucker.
>Vancouver,Canada.
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