Per the title, Is O1 Steel a good "beginners" steel for working and heat treating in a semi small, non PID controlled gas forge? Strictly stock removal. What are the pros and cons of blades from O1? I know this has probably been answered before but my search abilities are about as good as my knife making ones. Merry Christmas everyone! Don
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Is O1 Steel a good "Beginners" Steel?
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Willie71
Warren J. Krywko
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At minimum you will need a pyrometer to show stable temps in the forge, as Stan said the soak at 1200. I use 1475 for 10 minutes and consistently get Rc65 out of quench. A kiln is the way to go, with the full 20min soak, but you will get a very good heat treat with a 10 min soak at 1475. Longer in a forge and decarb becomes a problem.
I'm very curious about the decarb issue- I mostly see decarb in my forge at higher temperatures.
So many people run their forges with an oxidizing mix- is it possible that at 1475 and under in a rich fuel mix O1 might do very well? After all, there's plenty of free oxygen available in a kiln (oven).
Hoping the metallurgists will chime in....
So many people run their forges with an oxidizing mix- is it possible that at 1475 and under in a rich fuel mix O1 might do very well? After all, there's plenty of free oxygen available in a kiln (oven).
Hoping the metallurgists will chime in....
I cannot think of any reason that your gas forge could not get to temp in a reducing atmosphere. You will produce more carbon monoxide 
so make sure your shop is well vented. I am guessing that you would have less decarb in a reducing atmosphere but I have no idea how much.
so make sure your shop is well vented. I am guessing that you would have less decarb in a reducing atmosphere but I have no idea how much.
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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LRB has the answer.
Adjust the forge to run efficiently with a neutral atmosphere, and coat the bale to prevent oxidation.
There are dozens of products and methods to coat a blade, but they all do the same thing .... keep the oxygen away from the steel surface. A thin wash of ATP/satanite/Brownell's PBC/clay/etc will also help with more even heating of the blade.
Now, about O-1 as a beginners steel.
It used to be recommended as a good beginners steel often....because it was readily available. That has changes with the availability of many types of blade steels from all the suppliers today. The interconnected world of today makes availability only a few keystrokes away from any product you need, and accessibility is only as far away as your mail box.
O-1 is ( very basically) iron plus 1% carbon, with chromium, tungsten, and nickel added. This gives it some advantages in certain abilities. It does not make it a superior steel, but a properly heat treated O-1 blade will be a very good knife (with the proper blade geometry). However, the extra alloy ingredients need to get into solution. This requires holding the blade at a fairly steady temperature of 1475°F for about ten minutes. Most forges just are not capable of holding that temp evenly for any length of time. A new maker will not know how to tell the blade temperature well, and will almost surely overheat the blade in attempting to keep the blade hot for even one minute ( much worse for ten!). A thermocouple in the forge will help only a little bit, as the blade may be heated much higher by the flames than the TC indicates.
The answer is to use a similar steel without the alloy ingredients....one that will not need a soak time.
To the rescue comes 1084. This steel is called the eutectoid. That funny word means it has exactly the amount of carbon needed to bind up with the iron - No more, No less. It also has no other major alloy ingredients ( besides the necessary Mn and Si needed to make steel). This means that the blade only needs to be heated to about 100°F above the transformation point ( the temperature where the structure changes to austenite - AKA, critical temperature - around 1350-1360°F) to get all the carbon tied up with all the iron in a way that will lead to a good knife. Once the 1084 blade gets to around 1450-1500°F, you quench it immediately in a medium-fast speed oil. Canola oil from the grocery store will work fine. The temperatures can vary as much as 50°F without ruining the HT, the quench isn't super critical, and you don't have to hold it at the target temperature any amount of time. There is no steel simpler or easier to HT. The final result is a 100% martensite blade with great hardness and toughness.
A properly hardened 1084 blade will hold its own against any carbon steel knife blade. I regularly state that a 1084 blade with a good HT will beat any blade having a so-so HT on a "better" steel. To re-state that in a different manner - Good steel will not make up for bad HT.
Many makers are returning to 1084 for making high quality hunting and kitchen knives.
The newer 1084 alloys add a touch of any or all of these - vanadium , tungsten, nickel, chromium.
Just enough to make the steel forge better, but not enough to make the HT any more difficult. These alloys are often called 1084FG, 1084+, and similar names. Most of these are also slightly higher in carbon content to allow for some loss in forging. This is what is currently being sold by the knife suppliers.
1084 is a very good starter steel...and a very good advanced skills steel.
Adjust the forge to run efficiently with a neutral atmosphere, and coat the bale to prevent oxidation.
There are dozens of products and methods to coat a blade, but they all do the same thing .... keep the oxygen away from the steel surface. A thin wash of ATP/satanite/Brownell's PBC/clay/etc will also help with more even heating of the blade.
Now, about O-1 as a beginners steel.
It used to be recommended as a good beginners steel often....because it was readily available. That has changes with the availability of many types of blade steels from all the suppliers today. The interconnected world of today makes availability only a few keystrokes away from any product you need, and accessibility is only as far away as your mail box.
O-1 is ( very basically) iron plus 1% carbon, with chromium, tungsten, and nickel added. This gives it some advantages in certain abilities. It does not make it a superior steel, but a properly heat treated O-1 blade will be a very good knife (with the proper blade geometry). However, the extra alloy ingredients need to get into solution. This requires holding the blade at a fairly steady temperature of 1475°F for about ten minutes. Most forges just are not capable of holding that temp evenly for any length of time. A new maker will not know how to tell the blade temperature well, and will almost surely overheat the blade in attempting to keep the blade hot for even one minute ( much worse for ten!). A thermocouple in the forge will help only a little bit, as the blade may be heated much higher by the flames than the TC indicates.
The answer is to use a similar steel without the alloy ingredients....one that will not need a soak time.
To the rescue comes 1084. This steel is called the eutectoid. That funny word means it has exactly the amount of carbon needed to bind up with the iron - No more, No less. It also has no other major alloy ingredients ( besides the necessary Mn and Si needed to make steel). This means that the blade only needs to be heated to about 100°F above the transformation point ( the temperature where the structure changes to austenite - AKA, critical temperature - around 1350-1360°F) to get all the carbon tied up with all the iron in a way that will lead to a good knife. Once the 1084 blade gets to around 1450-1500°F, you quench it immediately in a medium-fast speed oil. Canola oil from the grocery store will work fine. The temperatures can vary as much as 50°F without ruining the HT, the quench isn't super critical, and you don't have to hold it at the target temperature any amount of time. There is no steel simpler or easier to HT. The final result is a 100% martensite blade with great hardness and toughness.
A properly hardened 1084 blade will hold its own against any carbon steel knife blade. I regularly state that a 1084 blade with a good HT will beat any blade having a so-so HT on a "better" steel. To re-state that in a different manner - Good steel will not make up for bad HT.
Many makers are returning to 1084 for making high quality hunting and kitchen knives.
The newer 1084 alloys add a touch of any or all of these - vanadium , tungsten, nickel, chromium.
Just enough to make the steel forge better, but not enough to make the HT any more difficult. These alloys are often called 1084FG, 1084+, and similar names. Most of these are also slightly higher in carbon content to allow for some loss in forging. This is what is currently being sold by the knife suppliers.
1084 is a very good starter steel...and a very good advanced skills steel.
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I used some 01 as a beginner and got mixed results. Got better consistent results with saw blade steel. But there was no interweb and I had never heard or 1084. 
If you are serious about using 01, it will take practice, testing, patience. But will make a good blade if you are persistent.
If you are serious about using 01, it will take practice, testing, patience. But will make a good blade if you are persistent.
Thanks for all the feedback guys. I'll stick w/1084 for now until I have a bit more experience and better equipment for holding proper temps for the correct time. Time to call Aldo and order some 1084 IF he has it in stock? Thanks again guys! Happy New Year!!
