Heat treating O1 and 5160

flatgrinder

flatgrinder

Joined
Dec 20, 2005
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Does anyone know if I can heat treat O1 with an oxyacteylene torch?

The reason I'm asking this is that I saw on Evenheat's website that the blade should be held for 15 to 20 minutes at 1450:

http://www.evenheat-kiln.com/techni...-1, AISI 0-6 Tool Steel Heat Treat Procedure:

(This would be hard to do with a torch). The reason I'm asking this is that I've tried heattreating O1 both ways, and the "holding it for 20 minutes" method produces a longer lasting and sharper edge.

By the way, is 5160 the only "officially accepted" steel you can properly heat treat with an oxyacetylene torch?
 
Steels like 5160 and 1080 are easy to heat treat and 'forgiving' so that using a torch [ with the proper technique] can work well.The more complex the steel the more critical are the times and temperatures.
 
Although I completely agree with mete, (as I often do), considering recent discussions, it may be better to give wide lattitude here and say that one can heat treat treat in almost anyway one likes and if the results are good enough for you and your customers,then it could be considered successful.

However for those who must have every bit they can out of the steel, the methods that will produce the conditions for which the steel was intended and that are recommended would be the best option. For what it is worth, since 5160 has chromium and barely enough carbon to reach maximum martensite hardness, not to mention some proeutectoid ferrite (sorry for the $5 word) to deal with, I personally would soak it as well for better performance, but it wouldn't be near as critical as O-1. The more I look into it the more I reccomend good old 1080/1084 for methods like torches; as simple as it gets- get it hot, get it cold real quick and you are done.

...The reason I'm asking this is that I've tried heattreating O1 both ways, and the "holding it for 20 minutes" method produces a longer lasting and sharper edge...
Click to expand...
You may have provided yourself with the answer then, since these results are almost universally the case. If you have both an oven and a torch, use the oven for worry free control. If all you have is the torch, get the job done anyway you have to and be happy with a hardened blade that you made yourself.

(darned! I may get the hang of this diplomacy thing after all ;) )
 
The trouble I have is that, only having a NC whisper low boy forge, the spine wants to get hard too. Maybe I'm just over heating it.
Is there a way to let an O-1 blade soak for 20 min in such a forge?
 
The best cutting knife I've made yet was 5160, and it was soaked for ten or fifteen minutes at I don't know what temp. The controller on my oven was not working at the time, so i was trying to compensate, and set it for 1650. I think it was probably 1550 actual temp. That's what I'm going to try next time i use 5160.
As for O1, I would definitely soak it. The knives I've made out of it were NOT soaked, and cut terribly. You can use a forge for soaking, by pulling the knife in and out of the forge to keep it from getting too hot, but you're still guessing what temp you're at.
 
Before I went on hiatus I was using some O1 and cavemaning it pretty badly. It worked, and some other makers who were using a LOT of O1 were doing the same thing (bringing to critical, no soak, then quench). The discussions tha ensued sparked me to read a lot of metallurgy stuff (against my will, but every knifemaker should do it eventually! Haha) and it was pretty convincing that O1 should be soaked to maximize its performance. So, you can make a workable knife without doing it, but you can do better. I found 1095 and 1084 a lot easier to work with, although precision ground O1 grinds like warm butter, which was refreshing, particularly after having used 1084 for years!
 
D.Krohn - Turn the pressure down on the gas and you can hold that Whisper Lowboy at a nice even heat for a long time.This is where a good pyrometer is a real advantage.The entire blade,including the spine will get hard upon quench (unless you are clay coating the spine).Temper the blade immediately after quench.When tempering is done you can draw a softer temper on the spine with a torch.
As Kevin said the soak time is needed to allow the carbides to get into full solution.For the average knife ( in simple carbon steel) 10 minutes is enough.
Again,as Kevin noted,the eutectoid steel (1080/1084) is the simplest to do.It has nothing but carbon and iron (basically).Heat it to 1450 stick it in anything from water to grease,and it will make a good knife or sword.
 
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