Deformation & new knife

Alden Cole

Well-Known Member
Hello all, just completed knife #13. This one has really bad edge deformation. Does anyone have any idea why that could be? Just carving wood I get some deformation. I think I got the burr off, maybe I sharpened to too fine an angle, or could my ht be bad? Any info is appreciated as I couldn't find anything online. By the way, the knife actually has some scratches on the blade, but the camera didn't pick 'em up.
Here are the specs.
Tiger wood
4.5 inches OAL
1080 1/8 inch thick
Flat grind, convex edge,
heat treated with mapp torch "forge", quenched in canola, tempered 400 2-2 hour sets.
Thanks in advance, you're critique always helps me improve!
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maybe I sharpened to too fine an angle, or could my ht be bad?

If you plan and execute the heat treat with it in mind, no angle is too fine. That being said, more information is needed to actually help you. Here's a tidbit of info concerning heat treat and sharpening angle..... IF the edge deforms under pressure, and stays deformed, then you heat treat is too soft for the edge angle you've applied. IF the edge deforms, and chips, then the heat treat is too hard. IF the edge deforms, and returns to true, then you have the correct WORKING hardness for the steel, grind, and edge geometry.

It's always best to err on the side of being too hard.....if the edge chips, put it back into the tempering oven, at 25F higher than your previous, and temper it again..... and so on, until the edge flexes and returns. (doesn't chip)

IF the blade is too soft....then you have big problems.... that requires you go through the hardening and tempering processes again.....problem is that the blade is thin, and usually will not survive the hardening process without severe warpage.
 
Ed has said it all, and is referring to the "brass rod test" concerning the edge. Do a search for "brass rod test" and you'll find lots of info. Here is a short video where about the 1 minute mark you can see the edge deflecting on a brass rod. The total video is only 2:45.
 
Alright thanks guys. After trying to do the brass rod test and messing around, I think that the blade is just too soft. Bummer. So if it's to soft this means that I need to ht better, right?
 
There is a possibility that you did not get full "as quenched" hardness...... OR...... you may have had your tempering temp too high..... either would result in a blade that is too soft.

Remember what I wrote above when trying to determine the correct working hardness for a given steel, with a given geometry, and if you err, try to err on the side of too hard.....which is easy to fix.

It takes time, effort, and sacrificing a few blades to determine the correct heat treatment. There is WAY more to it then "Get it hot, and cool it in something wet". ;)
 
I don't know how you are running your MAPP gas forge but try to spot the decalesense in the steel before you quench. I could be that the edge of the blade didn't austenize evenly. Right now, if you are thinking about salvaging the knife, you need to remove the scales and repeat the heat treatment.

If you are running something like a cheap two brick forge powered by a MAPP gas torch you might want to consider upgrading your setup.

Doug
 
Maybe this will help I hope. I quench 1080 in pre-heated canola oil and I temper at 400 two hours twice and I really like the results. If I were you I would look at my forge set up first. Maybe you did not get the steel hot enough long enough to complete the transformation. If you are using a magnet then go a little past critical temp before you quench. There are way more scientific ways to HT but this is one simple HT'er helping another. I go by color and or decalesense now but I started with a magnet. If you are an adult and you have access to an oxy-acetylene torch I think that may work better for you than Mapp gas.
 
Ya'll mention Mapp gas, but is it really any better than Propane gas? Propane with air combustion is 3600°F while Mapp gas is 3730°F - does that little 130F really make much difference while burning in open air?
 
IMO its likely the setup of the forge or the lack of forced air that makes the difference. Those little torches do not pull enough air flow and or there is no forced air (blower).
 
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Maybe this will help I hope. I quench 1080 in pre-heated canola oil and I temper at 400 two hours twice and I really like the results. If I were you I would look at my forge set up first. Maybe you did not get the steel hot enough long enough to complete the transformation. If you are using a magnet then go a little past critical temp before you quench. There are way more scientific ways to HT but this is one simple HT'er helping another. I go by color and or decalesense now but I started with a magnet. If you are an adult and you have access to an oxy-acetylene torch I think that may work better for you than Mapp gas.

So you temper at 400 deg for a total of 4 hours??
 
Yes. Two hours then let it go back to normal temp then two more hours. Some recommend three tempering cycles but I do two.

I believe that's your problem you should temper 2, 1 hour tempers at 400 or 1 2 hour temper. Your tempering the hardness right out of your blade. Check out attached video he does 01 but you can treat 1080 just about the same.

 
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I believe that's your problem you should temper 2, 1 hour tempers at 400 or 1 2 hour temper. Your tempering the hardness right out of your blade. Check out attached video he does 01 but you can treat 1080 just about the same.


This isn't the issue. You aren't going to over-temper a blade to the point of edge deformation with an extra hour of time on each cycle. Things happen MUCH slower in the tempering phase of heat treating than in the austenitizing phase. In fact so much slower that 1 hour might not actually be enough time in some cases. 2 temper cycles, 2 hours each is pretty standard operating procedure, probably used by more makers than those only doing 1 hour cycles.

As for that video you linked.....personally, I would not take any heat treating advice from a guy that posts a 'how-to' video on heat treating O1 with a small propane torch forge.
 
believe that's your problem

No offense intended brother but I think you have me confused with the original poster. The knives I produce with 1080 pass my tests with flying colors. As John said above two hour cycles are fairly standard. Truthfully there are many differing opinions about HT and the only way to be sure is to follow someone you trust and then test your results. That is what I did and now it does not matter if someone tells me to temper 10 15 minute cycles I know what gets the results I am after. I am familiar with Aaron Gough’s work and I know he has more tools to HT with than that thing he uses there. I think he is trying to show a minimalist approach here. I am surprised a little torch like that would run for an hour without freezing up and losing pressure. Like I said, not starting a fight just a conversation. Aaron is committed to testing and does good work.
 
This isn't the issue. You aren't going to over-temper a blade to the point of edge deformation with an extra hour of time on each cycle. Things happen MUCH slower in the tempering phase of heat treating than in the austenitizing phase. In fact so much slower that 1 hour might not actually be enough time in some cases. 2 temper cycles, 2 hours each is pretty standard operating procedure, probably used by more makers than those only doing 1 hour cycles.

As for that video you linked.....personally, I would not take any heat treating advice from a guy that posts a 'how-to' video on heat treating O1 with a small propane torch forge.

John this has worked well for me but you are definitely more in the know than I. Mr Gough is a full time maker also. But I always am willing to listen to learn something for sure.
 
No offense intended brother but I think you have me confused with the original poster. The knives I produce with 1080 pass my tests with flying colors. As John said above two hour cycles are fairly standard. Truthfully there are many differing opinions about HT and the only way to be sure is to follow someone you trust and then test your results. That is what I did and now it does not matter if someone tells me to temper 10 15 minute cycles I know what gets the results I am after. I am familiar with Aaron Gough’s work and I know he has more tools to HT with than that thing he uses there. I think he is trying to show a minimalist approach here. I am surprised a little torch like that would run for an hour without freezing up and losing pressure. Like I said, not starting a fight just a conversation. Aaron is committed to testing and does good work.

You are correct I thought you were the OP. I just know this has worked for me. Is it the best HT out there probably not. But when your just starting out and don't have a lot of experience or equipment it is a viable solution. Not looking to fight either. I want to learn how to make a GREAT knife that's why I'm here.
 
I don't mean to be rude.....but OMG!! That quenching/hardening video is a perfect example of someone who DOESN'T HAVE A CLUE, trying to tell others how to do something! The only thing following that video will get you... is FAILURE!
There are so much MISINFORMATION in that video..... I won't even attempt to correct it.

It boggles my mind to think of how many Knife Shaped Objects are being sold out there, and how many people are being ripped off, by people like this.....who don't yet have enough knowledge to produce a quality item, and are putting out/selling such poorly produced products!
 
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Hello all, just completed knife #13. This one has really bad edge deformation. Does anyone have any idea why that could be? Just carving wood I get some deformation. I think I got the burr off, maybe I sharpened to too fine an angle, or could my ht be bad? Any info is appreciated as I couldn't find anything online. By the way, the knife actually has some scratches on the blade, but the camera didn't pick 'em up.
Here are the specs.
Tiger wood
4.5 inches OAL
1080 1/8 inch thick
Flat grind, convex edge,
heat treated with mapp torch "forge", quenched in canola, tempered 400 2-2 hour sets.
Thanks in advance, you're critique always helps me improve!
View attachment 69045
View attachment 69046
I just thought of this: could you have overheated your edge in finish grinding or sharpening? Did the steel ever change color after you tempered it?
 
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