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Ernie Swanson
04-01-2011, 03:12 PM
Sorry for all the questions but I want to get this right.
I am getting ready to Heat treat some 1095 and O-1 in my oven, is annealing and normalizing required for blades that are made using the stock removal method?

If I were to do a few blades at a time how is that done, Do you open door, grab one, shut door, quench, then grab another? what about heat loss or to long of a soak time?

Does it matter if I were to use peanut oil, canola oil, or regular vegetable oil?

Do you let blades cool completely before tempering?

Oh ant what do you use to grab the blades and hold them while quenching? Tongs? where do I find a decent set just for heat treating.


Thanks for any help!

rob45
04-01-2011, 04:14 PM
Sorry for all the questions but I want to get this right.
I am getting ready to Heat treat some 1095 and O-1 in my oven, is annealing and normalizing required for blades that are made using the stock removal method?
I have heard conflicting opinions on this. It is my understanding that normalizing is required only to refine grain structure after forging. Much depends on your working methods and the steel in question.

If I were to do a few blades at a time how is that done, Do you open door, grab one, shut door, quench, then grab another? what about heat loss or to long of a soak time?
I haven't done more than one at a time, but I suppose that is the method I would use. Heat loss is inevitable, so moving quickly would be important. I am led to believe that reaching the target temps (avoiding over/under heating) is more critical than the soak times. As long as you move quickly, you shouldn't have too much of a problem with oversoaking.
I suppose the best method would be to heat at the "high end" of desired heat range in an effort to compensate for the heat loss, while avoiding overheating.

Does it matter if I were to use peanut oil, canola oil, or regular vegetable oil?
From what I gather, a purpose-made quenching oil is best. But I have successfully used both lightweight mineral oil and peanut oil. I have not tried vegetable oil, and do not intend to- the flash point is lower, and vegetable oil is the "heinz" of cooking oils. IOW, lower grading standards means a more unpredictable product. This does not necessarily mean that veg. oil will not work; it simply means that I do not know because I have not tried it.

Do you let blades cool completely before tempering?
Much controversy exists here. I let cool to black, then temper while still warm. When I say warm, I mean being able to pick it up, yet not able to hold for extended period of time.
Others report good results tempering after completely cooled.
Different strokes for different folks, I guess.
I don't yet know enough about the process to say one way or the other.

Oh ant what do you use to grab the blades and hold them while quenching? Tongs? where do I find a decent set just for heat treating.
Use whatever allows you to quickly and safely grab/hold/move it. Large pliers, tongs, etc.
Tongs can be purchased through the various blacksmith suppliers such as Blacksmith's Depot, Kayne & Son, Piehl, etc.

Thanks for any help!

I'm still very new to this myself, and have only made a few specialized woodworking tools (chisels, etc.)
Others with considerably more knowledge and experience will chime in.

Good Luck,
Rob

Michael Kemp
04-01-2011, 06:42 PM
I'm no Master Smith - but have beat my head against the do-your-own-heat-treat wall a little myself. The only thing I'd add to Rob's note is:

* don't let the blades soak in the oven too long - the grain size of the steel starts growing once you pass critical temp and you don't want that to get away from you

ARCustomKnives
04-01-2011, 07:31 PM
From what I understand, as long as you are using a controlled oven at the proper temperature (about 1475F for 1095) then grain growth shouldn't be a problem no matter how long you soak it.

As for heat treating multiple blades, I usually do 2 per "heat" and after taking the first one out and quenching, I'll close my door back up and let it return to temp for a couple minutes.

Just make sure you're not wasting time closing doors before you quench, as 1095 has a very quick cooling curve.

For holding the blades, some guys use tongs, or large needle nose pliers. I currently use large vice grip pliers to grab my blades.

Quench Oil: Different makers will tell you they prefer any of the three you mentioned... just make sure you heat the oil to about 130F. As for me, I used veg oil for a long time before switching to Parks 50, which is just about the best quench money can buy for 1095. It's a little fast for O1 though. For that, I still use veg oil.

Doug Lester
04-01-2011, 10:17 PM
Once you have ground the blade, I see no reason to anneal it. I would normalize at least twice to relieve any stress in the steel caused by grinding.

As mentioned, you have to move quickly between the oven and the quench tank and get the steel in the quenchant as quickly as you can safely move. I like to have my tank no more than one step from my heat treating forge. The steel must be above the A1 point when it enters the steel, especially for something like the 1095. Something like peanut or canola oil will do for quenching O1 and MAY be alright for 1095. If the 1095 does not want to quench in the oil you could order sme Parks 50 or use warm water. Water would be harsher than the Parks and could result in more cracked and broken blades. I would use neither for O1.

I would recommend that you let the blade cool to where it's only warm to the touch, especially if you want to wash the oil off in hot soapy water, before tempering it.

Heat is the most critical factor where grain growth is concerned. If you keep the oven temperature down to around 1450-1500 degrees F. then grain growth should not be a real critical factor. You should be able to soak for several minutes without problems. To begin with though, I would work with only one or two blades at a time. You could heat one blade to critical and pull it out to quench. After a several seconds in the quenchant you can take it out of the tank and set it aside for just a few seconds and put the next blade in the oven and let it heat up while you clean up the first blade and get it into the tempering oven. The alloys in the O1 will also resist grain growth unless it is overheated. Even the 1095 will not be all that bad if aluminum was used to deoxidize the steel during the melt. In short, keep the temperature in your oven on the low side while austinizing the steel and don't worry all that much about grain growth. It is a problem, especiallly with those who use a forge to austinize in, but it's not as bad as some make it sound.

Doug Lester

Ernie Swanson
04-01-2011, 10:27 PM
Wow thanks for all the info so far!

The problem I think I would have with doing more than one blade at a time is I will be tempering in the same oven as I am heat treating in.
So I will have to let the oven cool while the blade is cooling so I can temper.

Doug Lester
04-01-2011, 10:49 PM
Yes, tempering in the same oven that you are using to austinize the blades is going to present a problem reguardless of how you handle it. You are going to have to cool the oven to the tempering temperature after you have hardened your last blade. That means that the earlier blades will have to set aside as you harden the others. Depending on the number of blades that you have to heat treat, you may well get by with it. If you have many blades, I'd break them down into batches. Both steels that you are using are high in carbon and form plate martinsite which can generate small cracks which can propagate larger cracks. I also would not heat treat the 1095 and the O1 at the same time as I would expect the O1 to have to be tempered at a slightly higher temperature due to the chromium and tungsten content. Some times it just doesn't pay to rush the process.

Doug Lester

Ernie Swanson
04-02-2011, 05:52 AM
Doug, Thanks for that explination.
This is just a question I was thinking of, I will only be doing two at the most right now(at one time)
I do not plan to run the 1095 and O-1 at the same time.

ARCustomKnives
04-02-2011, 06:25 PM
You might want to check this thread out:
http://www.bladeforums.com/forums/threads/379832-How-the-hell-do-you-heat-treat-1095-!

It has a lot of great info on treating 1095, grain growth considerations, and otherwise.

On thing I'll mention considering Dougs recommendation on quenching in warm water:
You really need to add a specific percentage of salt (creating a brine solution) in order to get the most out of a water quench. If I recall correctly, it's something around 6 or 8% salt to water.

That being said, plan on losing a few blades due to cracking if you use brine. While it's probably the fastest way to quench steel, it's also very hard to do consistently without losing a few blades in the process.

Doug Lester
04-02-2011, 07:54 PM
One thing that I forgot to mention is that you could get a toaster oven to do your tempering in. Make sure that you are monitoring the temperature with a themometer and you could use a try of sand as a heat sink to help buffer the temperature changes as the heating coils cycle. That way you could get your steel right into a tempering oven.

A brine quench is another option but it is harsher than a plain water quench but there are those who quench 1095 in hot tap water or you could even heat it up to about 160 degrees to lessen the temperature shock to the steel. If you use water or brine you will have some blade losses so I would only try it if oil queching didn't work. With some of the 10XX series of steels, if they have a relatively low manganese levels, you may have to be that agressive in the quench to miss the nose of the ITT curve.

Doug Lester

franklin
04-02-2011, 08:59 PM
ernie i was plannig on getting some parks or dt-48 for 1095 if i get it glad to sell you a gallon from the 5

Ernie Swanson
04-02-2011, 09:08 PM
Heck that would work for me :)

franklin
04-04-2011, 03:13 PM
cool it should be sometime in the next month

Roger
04-04-2011, 04:55 PM
I may be late on this one but FWIW time from oven to quench is very important. Plan your move and make it quick. It made a big difference for me.