1095

C

camper86

Joined
Jun 8, 2008
Messages
17
Hello guys,
I'm Max from Ohio. Great site, lots of good info.

I am new to knife making and have done some research on heat treating some 1095 steel, but before i go jumping into it I want to make sure im doin it right.
Please correct any mistakes...

1. remove stock to get the basic shape of the knife.
2. heat to be red hot (1475-1550) and un-magnetized then soak for 5 min.
3. quench 2/3 of knife into 130-140 degree oil with the cutting edge down until flame is gone then quench the rest until smoke is gone.
4. temper immidiatly in 450 degree oven for 45 min then let cool to room temp. Repeat temper process.

My main questions are these.
Can I heat treat it without a temperature gauge in step 2?
Can I use olive oil or motor oil for the quenching?
What else am I screwing up?

Thank you for helpin the newb
 
forgot to mention, it gonna be a pretty hefty knife. probably about 12" x 2.5" x .25"
I figured that might affect the soaking times or something
 
JMHO, but I would suggest you think 1084, or 1080. It is more forgiving in HT. 1095 really needs to cool from 1500o, to below, if I remember correctly, 900o in the first one second of quench. You really need professional type quench oil to get it max hard and not crack it. I can tell you from experience that, although you think you got it hard enough, it may not hold a good edge after temper. 1080, and 1084 would be a better choice for using common oil. I would think you could use ATF with either of those, and get a decent knife.
 
+1 for what LRB said:thumbup:. O1 is pretty forgiving as well during heat treat.
I've never had any problems using a 1qt ATF / 48oz Corn oil / 1 qt SAE 30 mix (:rolleyes: It's what I had on hand at the time I needed to quench...)

also you can vary the temper temperature to achieve a more or less hardness.

heattrt.gif
 
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ATF = automatic transmission fluid, correct?

thanks for the input guys...so your saying that i should use the 1080. after it is un-magnatized i know its ready for quenching?
 
ATF = automatic transmission fluid, correct?
Click to expand...

Right :thumbup::D

Yes on the 1080/1084 It's the perfect steel to use starting out, O1 is really user friendly to though and may be easier to find ;) although if your forging most Lawn Mower blades are 1070 - 1080 . . .:thumbup:
 
Do your tempering for 2 hours at 400F, cool to room temperature (just stick it in a bucket of water - it won't hurt it at all), and them repeat the temper for another 2 hours. 45 minutes is not long enough.

You will also be better off with a full quench, and them drawing the spine temper down ( after the oven tempering) with a small torch. That way you will have a full martensitic blade with differential tempering. It will be a better blade, especially in that large size.
Stacy
 
The trouble with O1 is it really needs a longer soak than an inexperienced smith can do very well in fire. A furnace would be better. After looking at Kevin's micrographs, I can see what he's talking about when he says 5 min isn't enough for O1. I'd aim for 15 or more. BTW, he had some that soaked for 5 hours and still had fine grain...

+2 for 1084. And I think there is still 1/4" stock available in the "for sell" section here.

1095, especially in that thickness, may not fully transform in ATF or olive oil, leaving pearlite in the blade.

and + on what Stacy said


...my .02
 
could you explain "drawing the spine temper down with a small torch" a little bit... do you mean torching the spine? how long should i hold the torch on it?

and by "full quench" you mean putting the entire blade in right off the bat?

thanks again for helping the newb
 
Yes, a full quench is putting the entire blade immediately in the tank.
A differential temper is when (after tempering the whole blade) you use a small torch ( brazing tip or similar little flame) and slowly heat the spine up. The blade edge is usually sitting in a shallow pan with about 1/4-1/2" of water in it. The blade is rocked constantly to keep the tip cooled down, too. As the spine and main blade body heat up, the temper colors will "walk" down the blade surface (you have to sand the scale off the blade to clean metal first, of course) first showing a golden yellow, then pale peacock, the darker blue. When the darker blue is on the spine, the yellow should be down toward the edge area at the waterline. Just lay the blade over in the pan and let it cool, once you have drawn the spine down to the degree you want. This will often show a nice temper line when you polish and etch the blade. The spine will be softened much more than the edge (differential) and the whole blade will be tougher for it. It would be nearly impossible to break the blade from the spine while pounding it while splitting wood ,or with severe abuse. The edge might chip if you hit a rock,it might get stuck while chopping down a tree, but the blade won't break without a lot of abuse and bending
Stacy.
 
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You can also soak the blade on dry ice for 8 hours in between tempering steps. This was recommended to me by Mike Stewart of Bark River and resulted in a knife that I can tap through a nail with no ill effects.
 
That's because it is harder. You converted retained austenite (tough) to martensite (strong). I wouldn't recommend that for a sword.

IE, I can tap my HRC 62 cryoed D2 skinners with a .015" hollow ground edge through a nail with no ill effect too, but I certainly wouldn't recommend that alloy, HT or geometry for a sword...
 
CAMPER86. When you bring the blade to non magnetic, go what you think is 50o, to 75o hotter, then quench. In my oven that would be a bright red-orange. Non magnetic is not quite enough to get good solution, and you are going to lose a little heat getting from the heat source to the quench.
 
We are talking 1095 here. Simple carbon steels will not be changed to super steel with cryo.Martensite is martensite, no matter how cold you get it.If you had 1095 blade that you could tap through a nail, it is because the edge geometry and the HT were good....that and the fact that Rc 59 steel is much harder than Rc30 nails.It was not because you put it in dry ice.
The retained austenite in 1095 will convert with two temper cycles and cooling to room temperature between cycles.

The things that affect conversion are the amount of alloy ingredients and the time at temper. For all simple carbon steels,like 1095, most all of the retained austenite will convert on the first temper. The second temper is to temper the new martensite, which is untempered (and unstable) after the first temper, since it won't form until the steel cools to room temperature again. The important thing is to cool the blade to about 80F upon quench and between tempers.That is where the conversion stops (the Mf point)

With the addition of large amounts of chromium, and other things like vanadium and tungsten, the Mf point for austenite to convert to martensite is lowered down around minus 100F.
Thus, most stainless steels and high alloy steels can benefit from a cryo quench (it is actually the bottom of the quench cooling, not a temper). A snap temper at 200F, to slightly stabilize the martensite before cryo is a smart thing to do to avoid cryo cracks.
Stacy
 
Boy it is nice having somebody like Stacy around to help save on typing; I can't add much to what he has said, nor was very eager to do so. I do often bite my tongue and find something to do when cold treatments are discussed with simple carbon steels because I do not want to the be bearer of bad news- the bad news being that if you are seeing marked gains in hardness with such a steel, something is going drastically wrong in the initial heat treatment and it would be much more productive to troubleshoot there. Now of course we could get into all the pyramid-poweresque theories about cryo but we aren't really talking about the prescribed ultra-controlled cooling to -320F for extended periods now are we;).

I would have to really think about what somebody was doing with 1084 to end up with leftover austenite, but I can tell you how to justify all kinds of cold work with 1095... just overheat it. More than once in this thread a range for austenitizing 1095 had been given to include temps above 1500F. Once again 1084 can handle slighly higher temperatures and still forgive you but 1095 will not. I know that one source is a printing from a supplier, but I can say that it would not be the first time that source has been wrong, I once saw some information on O1 that was really messed up.

This is an interesting study in exactly how many misconceptions arise in the knifemaking world. We use our best guess at temperature in a forge (which almost always runs to the high side, unless we intentionally undershoot) for temp. or we follow actual written directions that may not be the best for our applications, and then decide to give some cold treatments a try and find the frozen blade to be quite a bit better. The problem now arises when we stop asking questions and assume the blade is superior, after all we followed the suppliers directions so the heating part has to be right, instead of troubleshooting the entire process and asking what problems the cold treatment could be correcting. After all , it is far better not to get cut at all then having to put a band aid on the injury afterwards.

Assuming a knife like one of mine is what anybody would want to make this is how I would do 1095

Austenitize at 1475F for 8-10 minutes and then quench in Parks #50 with appropriate agitation.

Begin tempering at 400F for at least an hour before checking how the resulting hardness will match my application. Then bump up the temperature and go for another cycle. If you thoroughly austenitized the steel don't be surprised if you end up going as high as 500F or better to get as low as 58 or 59 HRC, 1095 is like this and I have been amazed at how hard it will stay in tempering. Due to other peoples equipment and methods these results will vary slightly so I am hesitant to give exact temps, but instead encourage folks to walk the temp into the desired hardness and when you find it give the blade a good 2 hours at that temperature.

A lot of 1095 I have been looking at these days is highly segregated with nasty bands running through it, good hot normalizing cycles will break this up and a proper soak time will keep the carbon from regathering in those areas. If these steps are not taken it is not uncommon for large fractures to follow these bands.

Wait a minute for all the typing Stacy was supposed to have saved me this post was still half a page:(
 
Hi folks,
Would anyone mind commenting about torch drawing the spine of a blade. It seems the proper tempering of steel requires 1 to 2 hrs., possibly twice at a chosen temp. Is torch drawing a spine with the edge in water effective if someone can spot color changes in a relatively short few minutes. Just curious, not questioning techniques.

Thanks much, Craig
 
Drawing the spine is not going to replace proper tempering of the edge, they accomplish different things, you'll need to do both.
 
Different methods of heat treating different parts of the blade seem to be really popular. With the clay or edge quench, I almost get it, being that the hardening line is considered beautiful, and people go out of their way to make really high activity in that area for a really striking hardening line.

Given the choice between the two, though, I think, personally, I would rather a knife that was completely hardened and the spine drawn back over one that was hardened at the edge but not the spine.

The problem I have with the latter of the two, though, is exactly where Craig's question is coming from. By keeping the edge cool, and using color to torch draw the spine, you are effectively using more heat (higher temperature) to impart the same effect over a shorter period of time. The questions that bother me about that idea are HOW MUCH more heat? just how hot am I actually getting the spine of the blade if I do this? the other question that pokes me in the grey matter is what else is happening at that temperature? Sure, the spine is getting tougher, but why, and is the expansion the spine will experience because of heating going to cause stress problems at or near the line where the cold edge is not expanding. Is the re-contraction upon cooling going to make those problems go away or get worse?

Overall, if you need a blade for a high impact application, like a machete or heavy camp chopper, I would rather see the whole blade be drawn out to a higher temperature, making whole thing tougher. If the hardness vs toughness curve isn't acceptable with 1095, why not experiment a bit with something like 5160, which, as I hear told, makes some really excellent choppers.

It's one thing to go after the pretty hamon, which, for art and collecters peices certainly adds to the asthetics, but won't hurt the application. But when you need a tough blade for a user level application, my own preference, at least, seems to be leaning towards a full heat treat more appropriate to the application. If that means picking a different steel, so be it.
 
thanks for all the help guys, just two more questions if you don't mind...

if i go with the 1080 or 1084 because its more forgiving in the HT, how long should i soak it?

and could anyone give me a couple places to besides this site and admiralsteel.com to get some bar stock?
 
just ran across one of kevin chashen's webpages and i see that there is virtually no soak time for the 1084.
 
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