heat treating pry bar

[Chas]

I have a 5/8",30" long pry bar that has a messed up 'wedge' end. Getting it
the right shape using a forge would be no problem. But returning its
strength is beyond my knowledge.
. . .Sure would appreciate some tips on the treating of this bar, otherwise
I would just wreck it.. . . .in advance thanks to 1 & all....chas

[Ecnerwal]

In article <F3C6r.2864$QL5....@newsfe01.iad>,

Assuming it's suitably heat treated right now, the easy approach in most
cases (not having seen how it's messed up) is to grind to correct it,
maintaing a low temperature (go slow, use coolant, etc.), so you don't
have to take on a large-object heat treating.

IMHO, etc.

You could try to "just work on the end" but then I think you'd end up
with a too-soft zone where it would be prone to bending in use.

Heat treating the whole bar is about as easy as doing a sword - ie, it's
not, for nearly all of us, self definitely included. Also further
complicated by having to make assumptions about what it might be made
from that will affect the process. Heating the whole thing to critical
temperature is difficult without a special forge for long things. If you
assume it's water-hardening, quenching might be relatively simple. I
think you'd want a spring temper (blue oxides) over most of it, but you
might want the tips a bit more like straw.

That is admittedly making assumptions that these things are even done in
the normal course of manufacture, rather than just leaving the body soft
- but it certainly seems like a good one would be done that way, and one
not done that way would be more prone to bending in use.

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

[Chas]

Thanks Ecnerwal.
. . . .Your suggestion to just do a grind job is undoubtedly the best
solution in my case. I'm sure I could heat the entire bar in my propane 5
gallon can forge, but I would have to keep it moving to get both ends evenly
heated with the middle (hopefully). I watched Japanese sword makers on TV
and they have long charcoal forges but still keep the sword moving at all
times.
. . .. Since I am really a novice the grinder is my best bet. . .thanks
again. . .chas
*****************************************************
"Ecnerwal" <>

>
> Assuming it's suitably heat treated right now, the easy approach in most
> cases (not having seen how it's messed up) is to grind to correct it,
> maintaing a low temperature (go slow, use coolant, etc.), so you don't
> have to take on a large-object heat treating.
>
> IMHO, etc.
>
> You could try to "just work on the end" but then I think you'd end up
> with a too-soft zone where it would be prone to bending in use.
>
> Heat treating the whole bar is about as easy as doing a sword - ie, it's
> not, for nearly all of us, self definitely included. Also further
> complicated by having to make assumptions about what it might be made
> from that will affect the process. Heating the whole thing to critical
> temperature is difficult without a special forge for long things. If you
> assume it's water-hardening, quenching might be relatively simple. I
> think you'd want a spring temper (blue oxides) over most of it, but you
> might want the tips a bit more like straw.
>
> That is admittedly making assumptions that these things are even done in
> the normal course of manufacture, rather than just leaving the body soft
> - but it certainly seems like a good one would be done that way, and one
> not done that way would be more prone to bending in use.

************Original Post below******************

[Curt Welch]

Thick items like that are fairly simple to heat treat. They aren't swords.
They don't need to hold and edge or have a high quality heat treat. After
forging, just heat up the end you modified to just above magnetic and
quench in oil. You seldom even need to temper it because the mass of the
bar is so great that it won't be able to cool fast enough to become
brittle. The exception of course is on the sharp edge at the end. After
quenching, hit it against the anvil of something hard to see if it's
brittle enough to break (with safety glasses on of course). If its not,
you are good to do. If it breaks, forge it to a new point, heat treat
again, and then temper the end with a torch. I've done on this on multiple
crow bars.

If the defect is so small that you can fix it by a little grinding instead
of forging, then you should just grind it instead of wasting your time
forging and heat treating.

The heat treating from the factory will probably be better than such an
odd-hock approach like above will do, but crow bars get most their strength
from their thickness, not from heat treating. Swords are a totally
different story. when you want to make a 1/4" thick sword and make it
strong enough to act like a crow bar, while at the same time not being so
brittle it will crack on you when you bend it, the heating treating has to
be very precise.

Crow bars are just big thick pieces of steel that are strong because they
are big thick pieces of steel, not because they were carefully heat
treated. The heat treating is not that at all crucial unless you intend to
push the thing way past it's intended design limits.

And if you are a blacksmith, then you need not worry about bending it,
because if you do, you just heat it up, hammer it straight, and quench it
again. :)

--
Curt Welch http://CurtWelch.Com/
cu...@kcwc.com http://NewsReader.Com/

[Chas]

Thanks.
. . . .I measured the bar and it is a small one...1/2" x 24". I have some
OCS coils so I could have an exercise is making one if I screw this one up.
I take it that 'above magnetic' means that the bar is hot enought that the
magnetism has just left at the lowest temp possible?
***********************************
"Curt Welch" <cu...@kcwc.com> wrote in message
news:20120315095248.088$X...@newsreader.com...

[alv...@example.com]

Chas <footb...@bresnan.net> wrote:
> I take it that 'above magnetic' means that the bar is hot enought
> that the magnetism has just left at the lowest temp possible?

A qualified yes. :)

And whatever alloy it is will automatically take care of itself.

That's the difference between a blacksmitch and someone using a
temperature controlled oven. The latter needs to know a number to
bring the steel up to, the former don't need it, the steel tells
you when it's ready. (if you're listening;)

I don't use a magnet on my thin knife blades I watch for a shadow
to form in the steel. The "shadow" is from that-area of the steel
that's not yet past its -arrest point- and can be seen as darker
next to the area that has gone past the arrest point and so has
already begun to rise in temperature again so looks brighter.

Works for me anyway. ;)

David Boye mentions the method in his knifemaking book.

Alvin in AZ