I need to bend some round and half round files to use a rifflers. Can
anyone point me in the direction of a website that gives the details of
re-tempering the files after I've bent them. If I'm not mistaken the
process involves getting the file red hot and then quenching in oil. Then
bringing the file up to a specific temperature and or color for a sustained
period of time, and then quenching or letting it cool slowly, but I'm not
sure which.

In article OXkib.80675$pl3.16949@pd7tw3no,
"hedgeog" wrote:

I need to bend some round and half round files to use a rifflers. Can
anyone point me in the direction of a website that gives the details of
re-tempering the files after I've bent them. If I'm not mistaken the
process involves getting the file red hot and then quenching in oil. Then
bringing the file up to a specific temperature and or color for a sustained
period of time, and then quenching or letting it cool slowly, but I'm not
sure which.

You might want to try this question over on rec.crafts.metalworking.

--
Owen Lowe and his Fly-by-Night Copper Company
Offering a shim for the Porter-Cable 557 type 2 fence design.
http://www.flybynightcoppercompany.com
http://www.easystreet.com/~onlnlowe/index.html

Try this:

http://www.primitivearcher.com/articles/drawknif.html


Regards,
H


"hedgeog" wrote in message news:OXkib.80675$pl3.16949@pd7tw3no...
I need to bend some round and half round files to use a rifflers. Can
anyone point me in the direction of a website that gives the details of
re-tempering the files after I've bent them. If I'm not mistaken the
process involves getting the file red hot and then quenching in oil. Then
bringing the file up to a specific temperature and or color for a sustained
period of time, and then quenching or letting it cool slowly, but I'm not
sure which.

On Sun, 12 Oct 2003 22:53:34 GMT, "hedgeog"
wrote:

details of re-tempering the files after I've bent them.

Curved files are a tricky bit of heat treating, compared to re-using
old files as chisels or punches. Although we're spoiled today by easy
access to cheap high quality steels, a "tool steel" (i.e. one that
could be hardened) used to be a rare beast. Old files were a good
source of it and would often be re-worked into other hand tools.

If you're making curved files, especially for use on metal, start with
a brand new and unused file. Contamination of the teeth can cause
problems during the annealing and hardening processes, and you'll be
likely to find that your file is never as good a cutter afterwards as
it used to be.

To anneal files, you'll need a hearth. This is a small box of
firebrick, where you can heat them and allow them to cool slowly.
best thing is to go to an engineer's shop and buy some firebricks.
They're cheap, and they'll always be useful in the future. Every
workshop can use a simple hearth.
http://codesmiths.com/shed/workshop/hearth.htm
Get some extra bricks to pile up as surrounding material too.

If you don't have this, make a lash-up. Take the side cheeks out of a
coal fire and use them. Use the door of an old oven. Cast a bowl of
fire cement (or mix your own from cement and vermiculite - search for
woodstove making recipes). Be careful using building materials though
- most of them will spall when heated and fire sharp fragments at you.
If you're really stuck, just use a bucket of dry sand, heated over a
fire.

Be careful with the old "Leave it in the coal fire overnight"
approach. You need clean coal, or well-burned low-sulphur coke. House
fuels can cause havoc on good steel.

Then heat your files (big gas torch is good, or a solid-fuel hearth)
and get them to a cherry red. DO NOT OVERHEAT ! You really don't
want to burn the edges off those teeth. Hold them at this heat for a
couple of minutes, then allow them to cool as slowly as possible. This
is the time when your firebrick box is useful, or else a sprinkled
layer of hot dry sand. Keep the cold air off, and certainly don't let
water near them.

Batch heating files may be done by placing half-a-dozen of them
together. Turn them over and exchange them whilst heating, to make
sure it's even, but keep them close together whilst cooling.

Heating files, either for annealing or later on for hardening, will
burn the edges of the teeth. Traditionally they were always coated
with an oxygen-excluding paste. Makers had their own favourite
recipes, and these could range from inert clays to bread dough.
"Moist-bastos", an anti-distortion paste used by car body repairers
works too. Personally I use red clay from the garden, which has been
a traditional material for it here in Bristol for centuries. If
you're making coarse woodworking rasps, you can probably get away
without this layer. If you're making engineer's needle files for use
on hard steel, then it's essential.

Now you're ready to bend your files. Wrap them in lead sheet (roofing
lead) first, to avoid crushing the now-soft teeth. Expect breakages,
and don't work in a way where you'll slip if one does snap.

Your files will have been made of homogeneous cast steel, so you'll
need to harden them, then temper them.

To harden, heat the files to a cherry red and then quench.

Heating for hardening is much like annealing, with similar uses for a
firebrick hearth and a shielding paste. There's less need to hold at
the high temperature.

The temperature can also be determined very accurately (this is more
critical for hardening) by heating to the Curie point - which is also
the point at which a magnet is no longer attracted. Make yourself a
magnetic tester by wrapping a small magnet (not too powerful) with a
piece of coathanger wire to make a handle.

Don't use a hand-held magnet. You'll burn your hand getting that
close to a piece of red hot steel and you'll feel a right eejit when
the thing sticks to the workpiece and you've got no way to pull it
off.

I'd quench file steel in brine, rather than water or oil, but you
could use any of the three. Water risks cracking, but might be worth
doing if you're going to be working hard steel. Oil is good for big
rasps that'll get a hard life of being leant on. Use all of them in
a deep vessel and make a vertical point-down quench.

To make brine, pour salt into a kettle of boiling water until no more
will dissolve and there's a little left at the bottom. Then leave it
until cold.

Clean up the file and polish as best as possible. You might even use
a little hydrochloric acid to clean deep between the teeth.

Tempering makes the steel less brittle, and hopefully doesn't lose too
much hardness. This should be very subtle for a file - less so for a
hard-working rasp. You might even choose not to temper at all - bad
idea for a chisel, but reasonable for a small metalworking file.

Tempering is a matter of careful and gentle heating, to a very exact
temperature and then quenching (plain water is good). These
temperatures are usually described as surface oxidation colours, which
can be seen on a polished surface where they change in colour from
progressively lighter to darker colours. A file should be tempered to
only a "light pale straw yellow" - basically the first sign of colour
that you notice. To get even heating throughout the file, you'll
probably find it best to lay the file (one at a time) on a thick steel
sheet and then heat evenly from beneath. As it's only 430°F that you
need, you might even do this by placing the files briefly into a
pre-heated oven.


--
Die Gotterspammerung - Junkmail of the Gods

Wow this is great - thanx much
"Andy Dingley" wrote in message
...
On Sun, 12 Oct 2003 22:53:34 GMT, "hedgeog"
wrote:

details of re-tempering the files after I've bent them.

Curved files are a tricky bit of heat treating, compared to re-using
old files as chisels or punches. Although we're spoiled today by easy
access to cheap high quality steels, a "tool steel" (i.e. one that
could be hardened) used to be a rare beast. Old files were a good
source of it and would often be re-worked into other hand tools.

If you're making curved files, especially for use on metal, start with
a brand new and unused file. Contamination of the teeth can cause
problems during the annealing and hardening processes, and you'll be
likely to find that your file is never as good a cutter afterwards as
it used to be.

To anneal files, you'll need a hearth. This is a small box of
firebrick, where you can heat them and allow them to cool slowly.
best thing is to go to an engineer's shop and buy some firebricks.
They're cheap, and they'll always be useful in the future. Every
workshop can use a simple hearth.
http://codesmiths.com/shed/workshop/hearth.htm
Get some extra bricks to pile up as surrounding material too.

If you don't have this, make a lash-up. Take the side cheeks out of a
coal fire and use them. Use the door of an old oven. Cast a bowl of
fire cement (or mix your own from cement and vermiculite - search for
woodstove making recipes). Be careful using building materials though
- most of them will spall when heated and fire sharp fragments at you.
If you're really stuck, just use a bucket of dry sand, heated over a
fire.

Be careful with the old "Leave it in the coal fire overnight"
approach. You need clean coal, or well-burned low-sulphur coke. House
fuels can cause havoc on good steel.

Then heat your files (big gas torch is good, or a solid-fuel hearth)
and get them to a cherry red. DO NOT OVERHEAT ! You really don't
want to burn the edges off those teeth. Hold them at this heat for a
couple of minutes, then allow them to cool as slowly as possible. This
is the time when your firebrick box is useful, or else a sprinkled
layer of hot dry sand. Keep the cold air off, and certainly don't let
water near them.

Batch heating files may be done by placing half-a-dozen of them
together. Turn them over and exchange them whilst heating, to make
sure it's even, but keep them close together whilst cooling.

Heating files, either for annealing or later on for hardening, will
burn the edges of the teeth. Traditionally they were always coated
with an oxygen-excluding paste. Makers had their own favourite
recipes, and these could range from inert clays to bread dough.
"Moist-bastos", an anti-distortion paste used by car body repairers
works too. Personally I use red clay from the garden, which has been
a traditional material for it here in Bristol for centuries. If
you're making coarse woodworking rasps, you can probably get away
without this layer. If you're making engineer's needle files for use
on hard steel, then it's essential.

Now you're ready to bend your files. Wrap them in lead sheet (roofing
lead) first, to avoid crushing the now-soft teeth. Expect breakages,
and don't work in a way where you'll slip if one does snap.

Your files will have been made of homogeneous cast steel, so you'll
need to harden them, then temper them.

To harden, heat the files to a cherry red and then quench.

Heating for hardening is much like annealing, with similar uses for a
firebrick hearth and a shielding paste. There's less need to hold at
the high temperature.

The temperature can also be determined very accurately (this is more
critical for hardening) by heating to the Curie point - which is also
the point at which a magnet is no longer attracted. Make yourself a
magnetic tester by wrapping a small magnet (not too powerful) with a
piece of coathanger wire to make a handle.

Don't use a hand-held magnet. You'll burn your hand getting that
close to a piece of red hot steel and you'll feel a right eejit when
the thing sticks to the workpiece and you've got no way to pull it
off.

I'd quench file steel in brine, rather than water or oil, but you
could use any of the three. Water risks cracking, but might be worth
doing if you're going to be working hard steel. Oil is good for big
rasps that'll get a hard life of being leant on. Use all of them in
a deep vessel and make a vertical point-down quench.

To make brine, pour salt into a kettle of boiling water until no more
will dissolve and there's a little left at the bottom. Then leave it
until cold.

Clean up the file and polish as best as possible. You might even use
a little hydrochloric acid to clean deep between the teeth.

Tempering makes the steel less brittle, and hopefully doesn't lose too
much hardness. This should be very subtle for a file - less so for a
hard-working rasp. You might even choose not to temper at all - bad
idea for a chisel, but reasonable for a small metalworking file.

Tempering is a matter of careful and gentle heating, to a very exact
temperature and then quenching (plain water is good). These
temperatures are usually described as surface oxidation colours, which
can be seen on a polished surface where they change in colour from
progressively lighter to darker colours. A file should be tempered to
only a "light pale straw yellow" - basically the first sign of colour
that you notice. To get even heating throughout the file, you'll
probably find it best to lay the file (one at a time) on a thick steel
sheet and then heat evenly from beneath. As it's only 430°F that you
need, you might even do this by placing the files briefly into a
pre-heated oven.


--
Die Gotterspammerung - Junkmail of the Gods

"hedgeog" wrote

: I need to bend some round and half round files to use a rifflers. Can
: anyone point me in the direction of a website that gives the details of
: re-tempering the files after I've bent them.

Although theory suggests that re-hardening should be done, I've made limited
use of bent rasps without instant deterioration of the cut. Maybe the rasps
will serve quite well for most timbers if left untreated.

: If I'm not mistaken the
: process involves getting the file red hot and then quenching in oil. Then
: bringing the file up to a specific temperature and or color for a
sustained
: period of time, and then quenching or letting it cool slowly, but I'm not
: sure which.

From what I've read, there is more to it than that. The correct process
involves, I believe, in heating/cooling the files while encased in clay.
Presumably the points could be eroded by exidation during the heating and
then be cooled too rapidly
during quenching, thus making the metal too hard and therefore very brittle.

Jeff G
--
Jeff Gorman, West Yorkshire, UK
Email address is username@ISP
username is amgron
ISP is clara.co.uk
Website www.amgron.clara.net