Ranking of Steels in Categories based on Edge Retention cutting 5/8" rope

Could we take the metallurgy discussion and split it off to a separate thread? I think that would help a lot. We could simply link to it from here and have the topic be, "Metallurgy in Sharpening and Cutting Performance [was: Ranking of Steels in Categories based on Edge Retention cutting 5/8" rope]." Although, maybe that is too long.

I love the discussion on metallurgy, just think it would be better served by its own thread.
 
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In my opinion there has always been a lot of valuable discussion in this thread, as evidenced by the 78 page length. Anyone that just wants the "scores" can always check the front page and ignore the rest.
 
Fancier said:
In my opinion there has always been a lot of valuable discussion in this thread, as evidenced by the 78 page length. Anyone that just wants the "scores" can always check the front page and ignore the rest.
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It's just that much of it has little to do with the original thread and doesn't contribute at all to the original subject. It makes reading for info specific to this subject long and tedious because of the huge amount of non related info. Some of the material would be great if added to a relevant thread or started in a new thread and it would make such contributions easy to find. But 78 pages that roam all over severely damage the thread's original purpose.
 
"79 pages that roam all over" is why I subscribed to this thread. So long as its somehow connected to edge retention... and on that note:

K390 rules! But M390 is my EDC. As far as a stainless that cuts aggressively and keeps its edge, M390 is pretty tough to beat for an EDC.

: )
 
Lagrangian said:
Could we take the metallurgy discussion and split it off to a separate thread? I think that would help a lot. We could simply link to it from here and have the topic be, "Metallurgy in Sharpening and Cutting Performance [was: Ranking of Steels in Categories based on Edge Retention cutting 5/8" rope]." Although, maybe that is too long.

I love the discussion on metallurgy, just think it would be better served by its own thread.
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Could you start a thread like you're describing? I would but I can't conjure up a first post of sufficient quality right now or I would.
 
I'm always curious about the "custom heat treat optimal hardness" part...

Do you actually know that it wasn't any complicate or any harder to heat treat one steel to higher RC hardness.

You can have any steel at higher RC just by austenitizing at higher temp, quench it faster and tempering in lower range. That has nothing do do with the custom thing man. Any company can heat treat M390 to 62 or CPM154 to 65 if they would like to do.
 
I'm always curious about the "custom heat treat optimal hardness" part...

Do you actually know that it wasn't any complicate or any harder to heat treat one steel to higher RC hardness.

You can have any steel at higher RC just by austenitizing at higher temp, quench it faster and tempering in lower range. That has nothing do do with the custom thing man. Any company can heat treat M390 to 62 or CPM154 to 65 if they would like to do.
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I agree to a point. I'd rather have someone like Phil Wilson running my steel at max hardness knowing he will be running it in a oven at his shop that is calibrated, run one blade at a time, quenched, cryoed and tempered just right rather than having it run in a batch in a large commercial oven . Phil can get it to a half point of where he wants it to be with steel he has used ( from the same batch, composition and thickness being important factors).

Getting the large batches of knives to two points ( say rc 57-59) is excellent quality control. Phil can fine tune his temps, times and quenches after making a couple of blades in that steel. It also helps that Phil makes knives for a different reason than somebody who does it to feed his family. He doesn't need to make X knives per month and IME with his work that helps! :)

I've heard that Doziers customs regularly come out after temper right at 60.5 rc batch after batch ( small batches, not the semi customs but his true custom he makes, not the ones shipping out of his shop going to several dealers).
 
shqxk said:
I'm always curious about the "custom heat treat optimal hardness" part...

Do you actually know that it wasn't any complicate or any harder to heat treat one steel to higher RC hardness.
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You are obviously not familiar with heat treating large batches of knife blades. In theory it sounds easy, in practice hitting the higher hardnesses is difficult. I know several instances where professional heat treaters could not achieve the desired hardness. Some blades were shipped to another heat treater with better equipment and tighter quality control and the new heat treater hit the hardness.

If it was easy everyone would do it.
 
Alpha Knife Supply said:
You are obviously not familiar with heat treating large batches of knife blades. In theory it sounds easy, in practice hitting the higher hardnesses is difficult. I know several instances where professional heat treaters could not achieve the desired hardness. Some blades were shipped to another heat treater with better equipment and tighter quality control and the new heat treater hit the hardness.

If it was easy everyone would do it.
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Then it was the problem of insufficient equipment or skill not about the difficulty.

I think you as a steel supplier already know that the temperature of both hardening and tempering are what set the hardness. If you can heat a blade to 1100c how much harder to heat it at 1200c? sure wouldn't be any problem to temper at lower temp, right?

Unless it was the limitation of equipment I don't see any much more involve to get the blade harder.
Yes I don't familiar with large batches of heat treating but I do familiar with heat treating with gas oven and salt bath barrel since I my brother is a knifemaker. Here is his site.

http://www.konrakmeed.com/webboard/upload/index.php?showtopic=13317

RC hardness were only some part of the edge holding quality. If a maker tempering at too low temperature or forgot to do it, then you have a super hard blade which wouldn't hold an edge.

From my point of view OP just rely too much about the RC hardness which I thing it quit inaccurate way to tell the performance of steel. Now there are people who read this thread and got the mindset like when he see X knife labeled at higher RC, he will instantly thought it was better than Y knife with the same steel but lower RC, it is just a big fault IMO.


Sorry for my poor English anyway, its not my 1st language.
 
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Wow! I submit to your knowledge and experience!

You should open a heat treating service. The knife world will beat a path to your door. Let me know when you finish your first batch of 500 M390 blades at HRC 62 +-1HRC. :rolleyes:
 
Your sarcasm isn't in any way appreciated.

What I want to tell is the RC hardness isn't the absolute aspect to tell the quality of heat treating as many people thought.

Heat treating D2 for example,
austenitized at 980c for 30min, plate quech and then oil quench, overnight cryo, 2 tempering at 540c and we should have a blade at around 59rc tested.

Another blade austenitized at 650c then oil quench with no temper at all would give you the blade which RC test around 59rc also.

At the same RC test, the first one will certainly hold a good edge while I'm not sure the second one would any suit as a cutting tool.

I'm not try to being smart@ss but some time it just annoying to see people judge the quality of steel just from the hardness. Optimal hardness always depending on your goal.
 
shqxk said:
I'm not try to being smart@ss but some time it just annoying to see people judge the quality of steel just from the hardness. Optimal hardness always depending on your goal.
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I don't think anyone would disagree that you cannot judge a blade's edge retention from rockwell hardness alone, but I don't see where that is happening in this thread, certainly not in the OP ... could you point to a particular post?
Jim has made an effort to indicate hardness when known, and also manufacturer, so that the same steel in different knives can be compared, and I see steels hardened to 60 Rc out-performing steels at 65 Rc, so it is clear from the first post that hardness is not the deciding factor in this type of edge-retention. Did YOU want Jim to discuss martensite/austenite levels or present micrographs of each knife tested to show what grain structure each presents at the edge?
 
Back to the front. Why is this not a sticky? I check it often when I consider various blade steels about which I am unfamiliar.
 
Bronco said:
New Years bump. Hope you're feeling better and on the mend, Jim.
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Thanks. :)


I hope so, hopefully I will be able to get some treatment soon so I can start recovering.

I can't do any testing at all until that happens I am sad to say, it hurts too bad, more of a hip injury really from what the Dr. said, but my whole leg starts hurting so bad I can't stand it...

I can only walk a short time also until the same happens....
 
Alpha Knife Supply said:
Wow! I submit to your knowledge and experience!

You should open a heat treating service. The knife world will beat a path to your door. Let me know when you finish your first batch of 500 M390 blades at HRC 62 +-1HRC. :rolleyes:
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Yeah, M390 isn't easy to get to 62 in a production setting as you know.

I have a Spyderco Military in M390 that tested to 61 RC, but I think that's on the higher size of the range...
 
The Mastiff said:
I agree to a point. I'd rather have someone like Phil Wilson running my steel at max hardness knowing he will be running it in a oven at his shop that is calibrated, run one blade at a time, quenched, cryoed and tempered just right rather than having it run in a batch in a large commercial oven . Phil can get it to a half point of where he wants it to be with steel he has used ( from the same batch, composition and thickness being important factors).

Getting the large batches of knives to two points ( say rc 57-59) is excellent quality control. Phil can fine tune his temps, times and quenches after making a couple of blades in that steel. It also helps that Phil makes knives for a different reason than somebody who does it to feed his family. He doesn't need to make X knives per month and IME with his work that helps! :)

I've heard that Doziers customs regularly come out after temper right at 60.5 rc batch after batch ( small batches, not the semi customs but his true custom he makes, not the ones shipping out of his shop going to several dealers).
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Phil also tests the blades to make sure the edges don't fall apart before he finishes them and sends them to the customers.

So you know you are getting a high performance blade that will really perform.
 
gine said:
Jim, thanks for the update. I hope you recover quickly. Take care.
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Thanks. :)

I really hope so too.

Should be going to a specialist soon I hope to get some tests ran to see what exactly I need treatment wise..
 
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