Heat treat procedure for 1095

F

Fox

Joined
Feb 6, 2000
Messages
406
I have been using 5160 for quite some time and been extremely happy with it except for the loss rate due to those infamous "inclusions" in the steel that pop up just when you think the knife is done. So, I decided to try some 1095 since I had some on hand. I ground some knives this week and want to heat treat them this weekend. The steel seems to be very clean. The technical information I have states that 1095 is the only 10xx series that should be quenched in water (saline). However, I have spoken with several makers who still quench 1095 in oil because they say it is easier than mixing a saline solution and you lose virtually nothing in performance. What is the general opinion of my fellow forumites regarding the quench medium? My recipe for 5160 is: normalize, heat to non-magnetic, quench and allow to cool, then triple temper. Will this work for 1095? All blades are hollow ground and 3/16" thick along the spine. I have heard from others that 1095 is also a little more prone to warpage - comments?

Fox
 
I would be careful brine quenching 1095. It's technically water quenching, but when you take it to a drastic cross section in geometry, the odds of it cracking get pretty high.
My recipe is: Normalize, heat to non-magnetic, edge only oil quench in a light oil(I prefer olive oil), then triple temper at 350f for two hours per cycle, waiting 24 hours between cycles. If I'm for some reason only going to do one temper cycle, I take it to 375, because one temper cycle at 350 is a bit too hard.
Hope this helps.

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Oz

"This is your life, and it's ending; One minute at a time."
http://www.freespeech.org/oz/
 
I've learned the down and dirty method for 1095 and 0-1 tool steel. These are similar in heat treat. I chose these two to learn on because they can be heat treated with the simple propane torch. I have to build a brick "hole" to contain the heat (the bricks I use have holes and I simply align four bricks and put the blade...).

I heat the blade to cherry red (I know the temp and that it's non-metallic, but I use the color since I have no other means available). If sparks fly and the blade turns brite orange, the carbon is being eaten by the flame, not a good thing. I immediately quench the entire blade in light oil (Olive as noted is great, doesn't smell as bad as motor oil) moving in the oil to the cooling process moving (do not move side to side or the chance of warping increase...)

If the carbon is burned off in spots, the blade will show some pock marks (like pitting) that will need to be removed at final grind. These are not very deep.

The tempering, once again, is by color. Light straw is near 61 to 60 Rc (too hard and brittle), medium straw is 59 to 60 Rc (best) and blue is too soft. Not easy to see the colors in the oven.

Pretty simple and non metallurgical, but effective. I used a scrap piece to test and get hardness levels to ensure I was on the right road.

I've used this for the knives I use and have excellent field results.

Dan
Hannon Bearpaw Knives http://www.freeweb.pdq.net/dhannon/hannon.htm
 
I have played around with 1095 and have tried both saline and oil quenches. The first time I went with saline but didn't have enough salt in the solution. When I smacked the spline on my anvil a hairline crack became very noticeable... the blade had cracked during the quench. On the other end be careful not to choose a heavy oil like linseed. I have tried this a well. The quench takes too long and the blade doesn't harden enough. I would opt for salad, olive, or a very light weight motor oil. I prefer salad oil. The temper is done as mentioned above... You can also selectively temper the spline by torching only the back portion. This leaves the blade at ~61-62RC but allows for some forgiveness. It works well with small 3-7" blades.

Hope this helps.

Steve
 
First i have to ask, what is your heat source?

I heat in a gas forge, on as low a tempature as i can keep it burning. This gives me a slower, more thourough heat. Remember that 1095 can possibly surface harden easier than a slower quinching steel. Also remember to NOT get it over critical tempature, too high a heat has ruined more blades than about anything (in my shop any way).

The method i use is very simple-

Heat quinching fluid to 120-130 degrees. ( i use 2/3 canola and 1/3 olive oil).

Heat blade to critical temp., slowly if possible.

i do a full quench (but only about 1/2-3/4 of the blade hardens as that is all that reaches critical before i quench).

after cooling somewhat, check visually for cracks, also notice your "slag" line as most of the carbon will "pop off" of the hardened area. If you where on the hot side you will also be able to see some porousity in the steel itself. any how, do a file check on your edge for hardness etc.

I then hand sand the blade to 120 grit and check for cracks again under the opti visor, give it a tap on teh back of the anvil as well.

Now comes the temper, i use a pre heated oven to 400 degrees on smaller knives and 450 on larger knives. I temper for 1 hour, and usually give about 5 minutes for "soak". I do a single temper only, as i have had great results with a single temper (and its what Fisk and Zowada told me to do ;-)

At this point, i heat the spine of the knife with a torch just past blue, to a blue/grey tint. (do this with the edge sitting in a pan of water, so it doesnt take heat). I generally only "draw back" the spine on big camp knives etc...

There is no 1 perfect way, i think you have to experiment and find method that suits you.

matt.

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"Eternal vigilance is the price of liberty"
Thomas Jefferson

www.lameyknives.com
 
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