Heat Treating?

[copuman1]

What are the steps from the beginning? I will be working with 1080.


Thanks Creston

[J. Doyle]

I work with primarily 1080 and I will share my methods. Others may have different ways.

I profile, drill all my holes and do any filework, then grind the bevels till the edge is about the thickness of a dime (around .040")

Then it's time to heat treat.

1. I heat the blade to a dull red color and let air cool. This is to make sure my grain is fine to start with and relieve stresses caused by grinding and drilling. I do this step 3 times.

2. Then I bring it up to temp (about 1515* F.) I see this color as solid orange in my darkened shop. Many folks say cherry red but everyone will see shades and call colors different.

3. Then quickly, but controlled (read safely and smoothly), right into the quench oil. Having your oil set up immediately near where you're heating the blade. You have to go from temp to oil pretty quickly.

4. Hold in oil till cooled then go into a 415* F. oven for two hours. Do this step 3 times.

That's how I do it and have been pretty satisfied with my results. Hope this helps.

[Ed Tipton]

Copuman1...I also make knives using 1080 steel and 5160 steel. I hand forge every knife I make using a propane forge, but I also do considerable grinding on each knife.

Prior to HT, I complete all forging and also do all my grinding except for the final edge. I also leave the edge thickness about .030-.050" thick to help eliminate any cracks during the HT process.

Once I am satisfied with the condition of the blade and it is ready for HT, I prepare everything on the forge, quench tank, and preheat my toaster oven which is where my final HT will be done.

Once the HT is started, I check the blade once or twice to assure straightness as it is coming up to temperature. I use a magnet to determine when the blade has reached the correct temperature since depending upon the color is too "iffy" for my taste.

Catching the correct temp on the upswing, Once it has reached the non-magnetic state, I return it to the fire very briefly to recover the heat lost from this last step...and then very quickly remove the blade from the fire and plunge it into the oil. In my set-up, I am able to go from fire to oil in about 3 seconds...the quicker the better. Once in the oil, I "stir" the oil with the blade until I am confident that the blade is has cooled sufficiently.

I then remove the blade from the oil, wipe the oil off, and visually check the blade for any obvious warping or cracks. I also hit the edge with a file to ensure that it "skates" rather than cuts. If the blade has warped, I heat the blade again and straighten the blade as necessary, and repeat the heat/quench cycle until the blade is straight and is without any warping or cracks.

Once the blade has been successfully hardened, I remove any existing scale and clean the surface until it is shiney or at least partially shiney. I try and keep the amount of time from when the blade comes out of the quench tank until it goes into the pre-heated toaster oven down to a minimum...say 2-3 minutes. I have actually had blades crack on the bench by waiting too long to get it into the oven.

God did not create all toaster ovens equally, so you may need to experiment with your oven to get the correct temperature. On my oven, I set it at 450 degrees, and I leave the blade in it for 1 hour. Using an oven thermometer to verify the correct temp can help with this step...but once removed from the oven, the blade should be about the color of Budweiser (or your preferred beverage), and should be even and without any great variations in color which would indicate that the blade is not consistant in it's treatment.

I have also found that using fire brick to shield the blade from the direct radiant heat of the burner, and positioning the blade on it's edge helps in achieving an even tempering. I have not found multiple cycles to be necessary.

Once removed from the toaster oven, I check again to ensure that there has been no warping or cracking during this entire process, but this is all just a natural part of my inspection process...I cannot remember ever having a blade warp or crack during the tempering process...but I always check anyway. I then hit it again with a file to make sure the blade is still suffucuently hardened befor proceeding with the final stages of knifemaking.

This is an overview of my process. It works for me...but that is not to say that my way is the only way. Others may elect to do more or less at different stages, but the final product will speak for itself. Adjust and "tweak" the process and make it your own.

I hope this helps.

[G?rard Heutte]

Originally Posted by copuman1

What are the steps from the beginning? I will be working with 1080.
Thanks Creston

Hi Creston,
Here is a list of the different steps from raw steel to blade... It can apply to 1080. I often use a similar steel for my blades.
http://coustil.free.fr/debutant_fabrication_gb.html
Following the links, you can find information on heat treating.
I hope this helps.