Tempering Steel
 

Having a debate here on how to temper steel. I have an ax head that the handle broke off, and I know you throw it in a fire to burn out the wood but then you have to temper it agan once it's been heated right? I always thought you temper it by putting the hot steel in a bucket of cold water but my DH says no....??

Re: Tempering Steel
 

Others may disagree but do not heat it..

Drill and chip out the broken handle do not
heat it....

Use a hand drill to remove wood and a punch to help
drive the old handle out of the head....

Edit:

If you burn out the old handle head you will destroy the temper
and unless you know how to re-temper you will ether make the
ax head too soft or hard.

Soft will not cut or hold an edge.

Hard the ax head could shatter and cause harm to you
and others.

Do not heat it




IMHO

Re: Tempering Steel
 

The quick/simple explanation: The tempering process is a partial reversal of hardening. First you have to harden the steel by quenching in water (or oil or saltwater as the case may be), which imparts hardness but also brittleness (that is if the steel contains carbon; pure iron doesn't harden when quenched), then you heat the steel to a temperature determined by its composition, which tempers it.

If you harden the steel without tempering it, it may crack under the strain of use.

This link may be of use:

http://www.anvilfire.com/index.php?b...0anvilfire.com

R.

Re: Tempering Steel
 

When I do a quench & temper for steel, I would quench the steel in oil or water (depending on the steel) from ~1550'F, then temper at ~500'F for 2-3 hours (depending on section thickness).

Re: Tempering Steel
 

So, get it good and hot, 1550F or as close as, quench it in cold water, then 500F heat for a couple hours?

Re: Tempering Steel
 

When I used to mess around making knifes I
would watch the color of the steel for temper
using oil or water....


Edit:

This chart is close to what I used back then..


http://www.anvilfire.com/index.php?bodyName=/FAQs/temper_colors_hardness.htm&titleName=Temper Colors and Steel Hardness : anvilfire.com

Re: Tempering Steel
 

If you do it that way the whole ax head would
be tempered.

Imo the cutting edge is the only part that needs
tempering, the rest of the head can stay soft...

Re: Tempering Steel
 

Yes. 1550F would be a bright orange color. It doesn't matter if your quench media is hot or cold.

Re: Tempering Steel
 

I'd like it all tempered, I use my axes for more than chopping wood. Driving spikes, pounding posts, anything a hatchet is too small for and the maul too heavy.

Re: Tempering Steel
 

one thing about quenching in water ... swish it about. Otherwise the Leidenfrost effect can cause uneven cooling and crack the steel.

Re: Tempering Steel
 

quenching hardens the steel normally a cold salt bath is used the salt acts as a heat conductor and allows
faster cooling and therefore allows either harder steels or the ability to harden with less heat just
depends what hardness you need. depending on initial heat the speed of cool and the steel to begin with
and you are left with anything from wood axe to stone chisel in hardness.

the lower the heat of the steel you need to get the desired hardness the better the steel will be

most mild steels i would want to harden to a good blade i would bring to a yellow glow if i wanted a steel drill or a chisel
i would bring it up to a white hot almost melting.


but that is not tempering and the steel will be brittle you need to give it
flexibility as well as hardness this is done by bringing the metal up to a lesser
heat and then allowing to cool slowly i would guese with an axe head
bring it up to a low red (just able to see the redness in the metal at night)
and slowly move it up above the fire.

also if you can heat the head to no more than tempering heat to remove the wood you have
effectively killed to birds with one stone.and it will not require rehardening.

dont know what alloys axes are made from now or what the carbon content of the steel is but that will all affect your exact optimal temps and procedure.

Re: Tempering Steel
 

Some good responses and some dumb ones, you harden steel with a fire/quench, you temper it in an oven.

Simplest fix is to drill/punch out the old handle w/o messing with the factory hardening/temper job. If you're not proficient with metallurgy, you'll never get it back as good as it is now.

Re: Tempering Steel
 

The really simple fix is to go buy a new ax!


By the time you mess with all the tempering and invest time etc...


You could buy 5 axes!

Re: Tempering Steel
 

I took a class in this stuff. You have to study the charts a while to figure out what they are saying. Steel has several crystalline structures depending on alloy and temperature. Some of those structures take a certain time to develop. Quenching drops the temperature before any other structure can develop. In other words you need to know what kind of steel you have and you probably need advice from someone with experience in that field. So the bottom line is don't heat the thing; leave it the way it is and drill out the wood.