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If i used a oxy torch or a fire to heat a knife blank to orange hot and dipp it in some old motor oil. And the blank would be 1/8 thick at the most and probaly o1 or 1095
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If i heat steel to orange hot and put it in used motor oil whats the aprox hrc
- Thread starter benchmadebob
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seriously that wide of a range
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How much would it cost to get it heat treated by a pro?
Larrin
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It takes skill to get the right temperature, a magnet can help get you into a much closer range than "orange hot". Also, you're not even sure what it is, so yes, seriously that wide of a range.
Larrin
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Here's prices for TKS: http://www.texasknife.com/vcom/privacy.php#services
I can't seem to find the Paul Bos brochure, someone else can help you with those prices.
Hi,
Actually, judging heat treat by the color of steel is how it was done for far longer than we've thermocouples to measure temperature. And you can get very close by eye.
The trick is, it takes a fair amount of practice.
The problem with using a torch at home, is the heat will tend to be very uneven. One spot may be at the proper temperature, but the next too hot or too cold. That's why heat-treaters use ovens.
You would be better off building a small forge for yourself and using charcoal briquet's with an old hair dryer. Still not as good as a real oven, but better than an oxy-acetylene torch.
dalee
Actually, judging heat treat by the color of steel is how it was done for far longer than we've thermocouples to measure temperature. And you can get very close by eye.
The trick is, it takes a fair amount of practice.
The problem with using a torch at home, is the heat will tend to be very uneven. One spot may be at the proper temperature, but the next too hot or too cold. That's why heat-treaters use ovens.
You would be better off building a small forge for yourself and using charcoal briquet's with an old hair dryer. Still not as good as a real oven, but better than an oxy-acetylene torch.
dalee
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It depends on the steel. Most commercial blades carbon blades these days are made of 1095 or perhaps 1080 or their equivalents. 1095 when correctly heated and quenched in oil might be as high as 65 and probably won't be any lower than 56 based on what I've read.
Charcoal and a blower is a better option than a torch. Google "homemade charcoal forge". For the one blade that I did I just used a big pile of hardwood charcoal and a blower used to inflate kids toys---I brought the blade to orange then plunged it into a bowl of old 10W-30 and it came out so hard that a file would skate across the spine without cutting it!
If you just go to Lowe's and buy a bar of mild steel you can heat treat it until the cows come home and it won't be hard enough to make a knife. You have to make sure you start with a steel that's appropriate for knifemaking like 1095.
Esav Benyamin
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Moving from General Knife to Shop Talk ...
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BenchMade Bob
Just my $0.02 cents worth...
Have fun and experiment!
How long would it take to cut 5 near identical wedges from your stock?
Get yourself a magnet and thermometer in the 0- 212 range (you just want a good idea near the 150Deg area) a cooking thermometer will work.
Heating with an A/0 torch , for me is easer in the evening with out a lot of light.
You will feel the magnet get weaker, your close, when it dose not stick your there, dip it in the oil , do the same thing every time.
Try a sample with room temp oil, another at 140 Deg oil 150 and 160 and 170 deg oil.
Draw back the temper the same for all of them and run a few test. Just a from the hip guess, that your going to find a lot if differences in that spread?
There sure are better ways to do this, but not many are more fun then while your learning!
Just my $0.02 cents worth...
Have fun and experiment!
How long would it take to cut 5 near identical wedges from your stock?
Get yourself a magnet and thermometer in the 0- 212 range (you just want a good idea near the 150Deg area) a cooking thermometer will work.
Heating with an A/0 torch , for me is easer in the evening with out a lot of light.
You will feel the magnet get weaker, your close, when it dose not stick your there, dip it in the oil , do the same thing every time.
Try a sample with room temp oil, another at 140 Deg oil 150 and 160 and 170 deg oil.
Draw back the temper the same for all of them and run a few test. Just a from the hip guess, that your going to find a lot if differences in that spread?
There sure are better ways to do this, but not many are more fun then while your learning!
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Orange is about 1800' F and that would be too hot for 1095 or 01 I believe as they should be heat treated to around 1500 or so degrees.
Paul Bos only does Air hardening steels these days as he said it wasn't worth the $3,000.00 a year OSHA wanted him to pay in order to keep his quench tanks (or something like that).
Paul Bos only does Air hardening steels these days as he said it wasn't worth the $3,000.00 a year OSHA wanted him to pay in order to keep his quench tanks (or something like that).
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Yes but not with significantly alloyed steel, one of the reasons thermocouples were introduced to the process is to better deal with modern steels.
An excellent and most accurate answer Larrin, I wondered how one could answer the question without a two pager and you did in five words!:thumbup:
Also, orange, red, and yellow are colors, not temperatures. Colors are a function of the human brain interpreting information from the eyes based upon comparisons to the surroundings. Fortunately our brains are really good at it. But they cannot be linked to know we all see the same thing. On the other hand temperature is temperature; it entirely exits and is measurable outside of ourselves.
It is very easy to make a piece of steel strip the teeth off from a file and still be less than 50HRC in penetrative tests. A real good way to do this is to heat the steel just to non-magnetic and immediately quench it. Fortunately methods of heating such as forges, torches and our interpretive brains instead of the thermocouples will often result in overshooting the mark no matter how careful we are so we often end up with more into solution than just non-magnetic would allow. So I submit that it is our weaknesses and shortcomings that allow us to get successful heat treatments "the old fashioned way", not how good we are. Using a thermocouple to go the Currie point (non-magnetic) precisely will give you miserable results almost every time, while on the other hand using such a device to go to a proper soaking temperature will nail total success almost every time. The lack of this control is expressed quite well in Larrin’s post.
When I first started out making knives I had no HT oven and there was little information on HT ovens for knives back in those days.
I used an oxy torch with varying rates of success. Some knives failed, as they either did not get hard enough, or they warped.
Still others turned out very well, I have a few old knives that were HT with a torch that hold an edge better than the ones cooked in my Paragon HT.
I used 01 and even had good results from 440 C. Start out by making the flame just slightly on the fuel rich side to reduce the amount of scale. Using a torch produces alot more scale than using an oven because of the oxygen present using the open air method.
Keep the flame moving over the entire blade for even heating to produce an even heat treat. Do this for 25 minutes, keeping the blade orange. Then plunge in oil and temper at 400F in your kitchen oven for a couple of hours.
Then get prepared to remove alot of scale.
Using a torch is a good way to get started, but an HT oven is the way to go for consistency, and to avoid dealling with scale.
I used an oxy torch with varying rates of success. Some knives failed, as they either did not get hard enough, or they warped.
Still others turned out very well, I have a few old knives that were HT with a torch that hold an edge better than the ones cooked in my Paragon HT.
I used 01 and even had good results from 440 C. Start out by making the flame just slightly on the fuel rich side to reduce the amount of scale. Using a torch produces alot more scale than using an oven because of the oxygen present using the open air method.
Keep the flame moving over the entire blade for even heating to produce an even heat treat. Do this for 25 minutes, keeping the blade orange. Then plunge in oil and temper at 400F in your kitchen oven for a couple of hours.
Then get prepared to remove alot of scale.
Using a torch is a good way to get started, but an HT oven is the way to go for consistency, and to avoid dealling with scale.
Tai Goo
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It is significantly harder to get the absolute most out of 01 and other alloy steels. However, the stuff seems to make a decent blade even if you don't, and if you stick with it you can get very good consistent results judging the temperatures by eye etc. It takes some practice. I prefer doing it in a muffle tube, because the ambient or outside light will not have as great effect on the colors inside the muffle. It’s still a good idea to keep the ambient light outside the muffle as much the same as possible. I always heat treat about mid day in the shade. You can also use a magnet and check the color as a “reference point“, but not that that is necessarily the temperature you want to heat treat from. There are also ceramic slump cones and temperature markers you can use as "reference points". One thing to keep I mind about the muffle is that the light will be different inside it than outside. It tends to looks brighter inside the muffle, because there is less ambient light inside. Once you pull it out the color drops a bit. So, you have to practice with it and get used to judging colors inside the muffle...
Hardness testing is going to be very important. A flat surface of a file will start to skate around a Rockwell 50. However, if you get a nice fresh sharp triangular file and cut with the apex instead of the flat, or used the sharp corner of a flat or square file right across the edge (edge not thicker than about 1/16th of an inch or so), you can get a more accurate reading. It's more "penetrative". You basically decrease the surface area of contact and increase pressure. If you do not have close to full hardness, you will see some small indentations along the edge from the file this way. You should use some comparison testing with the file as well. In other words, compare the hardness to some other pieces of known hardness, drill bits, files, hand plane blades and other knife blades. It's also still a good idea to use some other types of hardness tests in conjunction with the file test, chopping hardwood and cold cutting mild steel for example... or just do some field testing for what the blade is intended for.
The old timers used to say that "01 is a very forgiving steel".
If you just heat it to a cherry red, give it a good soak, quench it in oil, and temper it good,... you'll be in the ball park. From there, just test it out, tweak your temperatures and timing if needed,... until you get what you are looking for. Then try to remember what you did or jot down a few notes.
It's that easy!
Hardness testing is going to be very important. A flat surface of a file will start to skate around a Rockwell 50. However, if you get a nice fresh sharp triangular file and cut with the apex instead of the flat, or used the sharp corner of a flat or square file right across the edge (edge not thicker than about 1/16th of an inch or so), you can get a more accurate reading. It's more "penetrative". You basically decrease the surface area of contact and increase pressure. If you do not have close to full hardness, you will see some small indentations along the edge from the file this way. You should use some comparison testing with the file as well. In other words, compare the hardness to some other pieces of known hardness, drill bits, files, hand plane blades and other knife blades. It's also still a good idea to use some other types of hardness tests in conjunction with the file test, chopping hardwood and cold cutting mild steel for example... or just do some field testing for what the blade is intended for.
The old timers used to say that "01 is a very forgiving steel".
If you just heat it to a cherry red, give it a good soak, quench it in oil, and temper it good,... you'll be in the ball park. From there, just test it out, tweak your temperatures and timing if needed,... until you get what you are looking for. Then try to remember what you did or jot down a few notes.
It's that easy!
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I love it, i read it and had a chuckle. it was almost like a movie villen monologing right befor he tryes to kill the good guy.
remember O1 will need to soak for a little so the carbon can desolve into the steel. i would say 7min at temp, which sometimes makes it hard because if you just stick it in the charcoal and let it sit there your are going to have very bad decarb spots because of over temp and the amount of time at that temp. keep the temp as even as possible and as close to 1475 as possible, (1425 = non magnetic)
