HEATING AND TEMPERING

[DANA HOLMAN]

CAN ANYONE TELL ME WHERE I WENT WRONG ON HEATING AND TEMPERING A BLADE.
FINSH A BOOT KNIFE BLADE, I HEATED IT TO WHERE IT WAS DEMAGNIZED, QUENCHED IT IN OIL AND TEMPERED IT AT 400 DEGREES FOR 1 HR.
CHECK IT WITH A FILE TWO DAY LATER AND I CAN FILE IT LIKE I NEVER HEATED IT. THIS IS O1 STEEL FROM JANTZ SUPPLYS. DID I GET A BAD PEICE OF STEEL OR DID I SCREW UP SOMEWHERE,

[robtattoo]

What kind of oil did you quench in?
What temperature was the oil?
How long did you soak the blade at non-magnetic?
How long did you quench the blade for & in which orientation?
How hard is the file you're using    ?

All of these things need to be pretty much exact & perfect to get 100% results.

You want a thin vegetable oil (NOT motor oil) heated to around 160 degrees. The blade (assuming an 1/8" thick blade) wants to be held at critical (Just above non-magnetic) temperature for at least 1 minute, preferrably 3 or 4. You need to quench the blade IMMEDIATELY after removing from the forge (Seriously, 1 second is too long!) edge down & hold it fully submerged until all the bubbles stop (Usually 1-2 minutes if you slice the blade back & forth)

Once you've got this far, de-scale the blade & test the edge with a sharp file. It should skate accross the edge. If it doesn't, repeat your quench. If it does, clean off a patch (Preferrably near the tip) on the blade & transfer it to your pre-heated oven (400 is fine)
You need to check on the blade every 5 minutes or so untl yousee your shiny patch turn a straw/gold colour. Once to this stage, hold at the temperature for 1 to 1-1/2 hrs & then turn off the oven. If you've only drawn the temper for 1hr, leave the blade in the oven to cool. If 1-1/2hrs you can remove it too cool off quicker.

As a rough guideline, if you've done every step perfectly you should have a blade somewhere in the region of 58-62 RWC (this is only a rough 'guesstimate' from my own testing)
At 58RWC a sharp file will remove metal from the edge, without any skating.

[DANA HOLMAN]

ROBTATTOO
THANKS FOR THE ADVICE, I DID USE MOTOR OIL AND THE OIL USE PROBABLE NOT HOT ENOUGHT, AS FAR AS THE MAGNETIC I GOT IT UP TO WHERE I TOUCHED  IT WITH A MAGNET ALL OVER AND THEN QUENCH IT. I DID NOT LEAVE THE BLADE IN THE OIL FOR 1-2 MIN. IT SEAMED TO BE COOLED OFF AND THEN PUT IN THE OVEN.THIS IS MY FIRST ONE TO HEAT AND TEMPER, THEN I TOOK IT FROM THE OVEN TO THE GARAGE(WHERE MY SHOP IT) IT WAS ABOUT 35 DEGREES. I'LL TRY TO DO IT AGAIN
THANKS FOR ALL YOUR HELP

[kbaknife]

That's one of the reasons I don't use O1. To really get it like it should be, and this is according to the Heat Treater's Guide, O1 needs to be held at nearly 1500 degrees for 20-30 minutes.
If you are using simple equipment and don't have real specific temperature control, use a simpler steel. O1 has a lot of alloys in it that require long soak times.
Not that it can't be done, but there are simpler steels to work with.
ONe thing to remember is that about 99% of steels go non-magnetic at 1414 degrees. It's the IRON that is going non-magnetic. But, there are a lot of other alloys in the steel that need to be taken into consideration when hardening. The alloys in O1 require it to be held at around 1500 for long lengths of time.
That's quite a bit hotter than when your magnet quit sticking!
Someone like Rob, who has a lot of experience with O1, has more than likely worked out a recipe for doing this.

[DANA HOLMAN]

THANKS KBAKNIFE
I DO NOT HAVE A FORGE, I HAVE A SMALL TORCH, IT TOOKE ABOUT 5-7 MIN. TO HEAT THIS UP TO NON-MAGNETIC, SO SHOULD I HOLD IT FOR ANOTHER 5-10 MIN OR SO? I HAVE HEARD OF GUYS USING MOTOR, SO THIS IS NOT WHAT I NEED, I WILL GET SOME OTHER OIL.
I'LL LET YOU KNOW HOW IT TURN OUT
THANKS AGAIN

[madness522]

If O1 is a complex steel and hard to heat treat without proper equipment can you recommend a good steel that the hobbiest can do a decent job of heat treating?

[robtattoo]

To be honest, if you've got a forge, it really is simple to work. Even I can use it succesfully!

Dana, you really need a forge to successfully heat a blade. It's impossible to evenly heat a blade with a torch & there's no chance on earth of being able to maintain a constant temperature.
Sorry, but it just can't be done! You should buy a soft firebrick & hollow it out. Poke your torch in one side & you'll be set.

[madness522]

Rob, how do you keep the heat constant for the 20-30 minute soak time with a firebrick and no thermometer that registers that high of heat?  

Dana, here is a simple firebrick forge I made. The most expensive part was the propane nozzle.
 

[DANA HOLMAN]

10-4 I THINK I'LL DO THAT, BECAUSE I WANT TO LEARN IT RIGHT THE FIRST TIME
IN THE FIRE BRICK IS IT OK TO LAY IT ON THE BOTTOM OR HAVE SOMETHING HOLDING IT UP IN THE MIDDLE
THANKS

[robtattoo]

The soak time given on 99% of sites is listed as time per inch of thickness.
A 1" thick blade would need the full 20-30 minute soak, whereas a 1/8" thick blade only needs 2-3 minutes  :D

I've got so used to 01 these days (it's pretty much ALL I use!) that I go by the colour alone, I rarely check my thermometer. I turn out all my lights & close the Workcave door, so my ambient lighting is a constant. As soon as the blade turns a dull red (Sorry, but it's too dark to photograph) I turn down the gas until the blade maintains that colour. Hold for 3 minutes & then IMMEDIATELY quench in warmed (160F) Olive oil.
If you have a thermometer equipt with a probe, maintain the ambient forge temp at 1450F (+/- 20F) & you're good to go.

[DANA HOLMAN]

THANKS ROB

[madness522]

Thanks Rob!  I can do 2-3 minutes.

[OconeeDan]

Some ideas here...
I bought an old electric fryer at a yard sale, I use that to heat my oil in.  You can use a cooking thermomoeter to verify temp.
I use a heat treating oven, you can find used ovens on the auction site.
The O1 works well for me, but I keep it in the oven while the temp is coming up.
Dan