Plate quench O-1, how thick can I go?

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gixxer

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Sep 21, 2006
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So, I am about to get my HT oven squared away and I want to start with something easy since I am not geared up for cryo yet. I want to use plates to keep everything straight (although I read that it is not perfect all the time, but the odds are stil better than oil). I had been searching threads about plate quenching O-1, and the only thing I could find was Butcher Block was plate quenching 3/32 stock. I am cool with working with 3/32 for the smaller stuff, but what about 1/4 stock? One other suggestion was going to A-2 for thicker stuff, but does that not require cryo?

I really wish I could afford a rockwell tester, since I am going to cook my own stuff, I want to make sure my stuff is good. but, that is another thread down the road when I have a grand or two saved up.

Thanks for the help, Merry Christmas to everybody!:thumbup:
 
I haven't heard of anyone using plates to quench thicker O-1. I would think it would be too slow for thicker stock. You may get the surface hard but not the core. I remember the thread you're referring to, but I haven't seen any info on it elsewhere. For what it's worth, I oil quench all the O-1 I use and haven't had a warp yet (5/32" stock). However, I did have a warp in a plate quenched CPM154 blade I did recently. I had the foil folded just slightly over the tip and it warped it away from the fold. If oil quenching, make sure your grinds are even and go edge first or tip first inro the quench, and don't move the blade side to side (tip to butt or edge to spine is ok, just don't get carried away). I don't know that A-2 requires cryo, but I'm considering it as well to move away from oil quenching. You should be able to achieve excellent hardness as quenched, but cryo will get you the max out of the steel.

--nathan
 
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O-1 is an oil quench steel. that is what the alloy is designed for. If you want to air quench (basically what you are doing with your plates) get the appropriate steel. If you are going to work with O-1 buy some oil

-Page
 
I don't think you'll get the desired results you're looking for by plate quenching "oil" hardening steel :D Works with A2 and air hardening steels, but like the other guys said, that probably is not going to work correctly.

Butcher Block was probably quenching some sort of stainless or Air hardening steels. But by all means, ASK him !!!
 
I remember the thread and he did air quench some thin O1. It could work if you had big enough plates and the knife was ground so you had good contact between it and the plates. no need for foil because you wouldn't get the O1 as hot as stainless.

But I think you are skating on thin ice doing this and don't see why you wouldn't just go ahead and oil quench it. Its not hard to stick it in oil. O1 really doesn't need a special oil and clean up isn't that hard. I give my oil quenched blades a spray of carburetor cleaner before the tempering oven. I use an electric oven to HT and have very little scale or decarb. Plus, like was said, you can have warpage when you plate quench too. If you have taper it is not likely to have complete contact all the way down the blade. You can straighten any problems while the blade cools from below 800f to 400f whether you use oil or plates.
 
If you are HTing in an electric kiln you can put some charcoal in the oven with it to consume any free oxygen to lower your decarb. With O-1 also make sure you give it a good soak at temp to make sure all the goodies go into solution properly

-Page
 
ok here we go
O1

I have NEVER air quenched O1
I have done some kitchen slicers with blades over 10 inch and a few 1/16 thick parers (worried about warping) that would not fit in my oil tank(parks 50)
blade info is
3/32 thick P ground stock profiled to shape and i broke the edge on the grinder (cutting the "bevel" at 45 degrees to save belt life after heat treat )
this was the unbeveled test blade (max quenching area) to see if i could make the time to under 800f (8 sec)
time line
from kiln to plate 2 sec (pull out slide in) 1 sec to get press locked down and by my 8 count (total) i could hold bare handed (try that with parks 50 )

blades then tempered when the kiln cooled off at 375f (2 hours )
next day hardness tested at 63rc in 3 spots on the blade

now then would i do 1/8 or thicker?
No that's cause that i would not be able to bevel the blade before heat treat
grinding away that much hard steel would be hard on belts so i never even gave it a shot to see
air quench steels i can bevel and not worry about the edge making the curve as it is so long

i will answer what i might have left out just ask

BTW cpmS30V has a data sheet that gives both with and with out cryo
 
All, thanks for the input. I was planning on knocking the edge off, and HTing the profiled blank to get as much contact as possible. True about eating belts. Although I was working over a blank of hardened CPM154 and did not think it was all that bad, so I was inclined to try majority of my work after HT to see how it worked. MAybe asking for a headache there, who knows. What I am striving for is the method to do everything possible to eliminate any instance of warp so I would not have to tweak the blade while hot.

I did know that using s30v without cryo was possible, but I did not want to use it till I was set up for cryo. IMO I do not want to use a steel unless I can fulfill my method above pertaining to warp, and also produce a product that I have done everything possible to ensure awesome performance depending on what it's "mission" is so to speak (of course edge geometry play a role here. don't count that out). If the blade finishes quenching in cryo, then that's what I need to do if using a given steel where cryo finishes the quench. Then again too maybe I am am making too much of a big deal out of that.

So then enough of the rambling. I can get away with 3/32 O-1 using plates, but no higher unless I want to experiment. Anything over that and I need to use something different. Any other thoughts?
 
btw my data sheet on s30v has it as an oil quench steel
there is a great gray area

many say that plate quench steels and some air quench steel is more marketing

seems that cpm154 has a data sheet that calls for air but to expect 1-2 points hardness extra if salt quenched

????? all the time and you get the fun part of playing with it and seeing

make friends with a tool and die shop and get lots of hardness tests
also make sure to beat the hell out of a test blade to make sure
just know what peramitors you are testing
i work with things as thin and light as razors and parers up to choppers and soon a crash axe (cant wait to make the tester for that )
 
If you are going to do this I would recommend getting some good sized plates and set it up so they clamp fast and have a fan aimed at them to help carry away the heat. I was wondering if going to a motor cycle junk yard and getting a couple of old finned heads and bolting them to the plates would help suck the heat out faster. If your going to do it, really set up for it.
 
my plates are 1 inch thick and 6x18 inch each
remember that its really only a big deal to get the steel under 800F that fast
even hot to the touch plates are less then 300f
parks 50 works great in part that it gets the steel under the curve and then slows down the cooling off rate
 
Butch, let's switch up the question a bit. Using s30v not cryo'ed, What design would you not use for fear of chip out? Skinner, shaver, to a big chopper?

I never had to worry so much about these questions cause I always sent my stuff to Paul Bos.
 
Hi - I don't have any info on plate quenching O1, sorry, but I wanted to comment quickly on grinding 1/8 or thicker after heat treat. If you haven't tried it Butch, give it a shot. I grind most knives after heat treat now, I just recently ground a 3/16" fighter that was about 12" OAL. Just grind it with ceramic belts and it won't matter how hard the steel is :D

This may not be true for all, but I feel that the blade is easier to grind hard, the steel comes off a little slower, but the scratches don't seem to go as deep and you don't end up regrinding at the same grit you stopped at before heat treat (or one lower). When you're finished grinding, you're finished grinding, very nice.
 
s30v i cant help with as i have only made a few kitchen knives of it and they were all thin and real hard (cryoed )

i just dont think that s30v is the greatest steel for everything like its marketed for
to me it might be one of the best folding knife steels out there

but other then that cpm3v and cpm154 are my go to
cpm3v can be done without cryo and i have done it but i always cryo SS
 
Well I guess I could always stick to the 3/32 stuff for right now. Besides who am I kidding? it's not like I am gonna be able to crank out a super 5/16 thick fighter with a 10in blade and have the HT come out perfect first time around ever firing the oven:p. I could always get some dry ice for the first couple times till I can get a Ln2 refrigerator. Baby steps...

Thanks for the help, Merry Christmas!!
 
heat treatign is not magic
read the data and see what you have to do per steel alloy

go from there
make a few test sample tabs and ahve the hardness tested and brake a few to see how it goes
make a test knife or few and beat on them

this is the best way
even when i get info from another maker i have to make one blade to see how things worked out (all kilns read temp a bit off and you may have to tweak things to nail the temps in you gear


and remember to just have fun havig heat treating tools makes testing a new heat treat easy
BTW if you try and plate a larger blade in O1 and it does not get hard you can always redo it in oil
 
butcher_block said:
this is the best way
even when i get info from another maker i have to make one blade to see how things worked out (all kilns read temp a bit off and you may have to tweak things to nail the temps in you gear
Click to expand...

More true words have never been spoken. I know Butch well and have seen how he tests his work. I'd venture to say that most makers don't do as much as he does to test "general usability" of his knives. Just a short list of things I've seen Butch do to "test things":

- Cut belts off of the grinder when he's done with them (If that won't kill an edge, I don't know hat will!)
- Hammer a knife through old wood pallets
- Pry old wood pallets apart with a knife
- Cut burlap...endlessly cut burlap...in rolls 4" thick....
- Chop down everything at the edge of the woods :)
- Use a necker as a chisel...on steel...with a ball pien hammer right on the spine

When I first met Butch I laughed at him for having an Evenheat while he was still using a 1x42 Delta to grind. I know better now...and he's gotten a KMG since, so I can quit laughing :)

-d
 
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