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

[Ankerson]

This is a long and useful thread, but I may have missed a few things. I don't know if I have read every page.
Did you rank the steels within categories, and how "broad" are the categories themselves? How did you decide where to make the cuts and define the categories?
I reread the first page, but I am interested in how you set this up.

The steels that are in the same category made exactly the same number of cuts as the other steels in the same category based on the testing method.

 

[Alpha Knife Supply]

Nitrogen in the steel does not form nitrides. It hardens the steel similar to what Carbon does. But it does not form nitrides.

Where do you get your information?

The information I cited is from a metallurgist who works with nitrogen steels. Maybe I misunderstood?

The performance of nitrogen steels has surprised me. My son-in-law made one of the first custom knives with N680. The performance of the knife surprised all of us. The edge is extremely toothy and aggressive. It is easy to grind, heat treat and sharpen. I did not want to send Jim a custom with N680 so I bought a new Benchmade folder and sent it to him. I've now seen a factory and custom knife made from N680 that show the same result. The steel is good for knife blades.

 

[arty]

I'd be really curious to see how steels like properly hardened 1095 can do in comparison to the other steels, as well as the 12C27 by Bark River.
It takes a lot of time to do all these tests, and the effort is greatly appreciated.

 

[Noctis3880]

Where do you get your information?

The information I cited is from a metallurgist who works with nitrogen steels. Maybe I misunderstood?

The performance of nitrogen steels has surprised me. My son-in-law made one of the first custom knives with N680. The performance of the knife surprised all of us. The edge is extremely toothy and aggressive. It is easy to grind, heat treat and sharpen. I did not want to send Jim a custom with N680 so I bought a new Benchmade folder and sent it to him. I've now seen a factory and custom knife made from N680 that show the same result. The steel is good for knife blades.

Hmm, sounds like it could be a viable replacement for Spyderco's H1. That steel gets to a decent hardness, but it really isn't very wear resistant and scuffs like titanium. Though I guess that depends on corrosion resistance. The N680 seems to hold up well to a salt spray, but I wonder how that test compares to a long dive in the ocean.

 

[Alpha Knife Supply]

Hmm, sounds like it could be a viable replacement for Spyderco's H1. That steel gets to a decent hardness, but it really isn't very wear resistant and scuffs like titanium. Though I guess that depends on corrosion resistance. The N680 seems to hold up well to a salt spray, but I wonder how that test compares to a long dive in the ocean.

In my opinion, H1 is the best for corrosion resistance.

The salt spray test is a accelerated corrosion test. If I understand the test correctly the result is equal to about a month of submersion in salt water. Unless your dives are more than a month long you should not have problem!

 

[Ankerson]

Where do you get your information?

The information I cited is from a metallurgist who works with nitrogen steels. Maybe I misunderstood?

The performance of nitrogen steels has surprised me. My son-in-law made one of the first custom knives with N680. The performance of the knife surprised all of us. The edge is extremely toothy and aggressive. It is easy to grind, heat treat and sharpen. I did not want to send Jim a custom with N680 so I bought a new Benchmade folder and sent it to him. I've now seen a factory and custom knife made from N680 that show the same result. The steel is good for knife blades.

I saw that too, even with the polished edge on N680, extremely aggressive cutting the rope.

 

[knarfeng]

The Bohler Tech Data sheet for N680 says that it forms fine carbides. So does 420HC. Fine carbides that do not appreciably improve abrasion resistance. To get significant amounts of the carbides that do increase abrasion resistance, you have to have above 0.77% Carbon.

The sheet also says that the nitrogen is there to help the hardness. No mention of Nitride formation.

The focus of the Bohler Tech Data sheet is that this alloy can be hardened to ~57, giving it a good hardness for cutlery. It also says that it has good resistance to corrosion in chlorinated environments. Sea water is such an environment. It also says that it takes an exceeding fine edge. Alloys that don't form significant levels of carbides tend to have that property.

Today at work I talked about N680 to a metallurgist who specializes in stainless steels. I showed him the tech data sheet. I asked his opinion about nitride formation. His opinion is that it does not form the type of nitrides that would enhance abrasion resistance.

I can't comment on the actual edge retention performance because I've not tried N680. I will say that I've tried a number of other steels listed in this thread and strongly disagree with some of the rankings.

 

[jimnolimit]

The Bohler Tech Data sheet for N680 says that it forms fine carbides. So does 420HC. Fine carbides that do not appreciably improve abrasion resistance. To get significant amounts of the carbides that do increase abrasion resistance, you have to have above 0.77% Carbon.

The sheet also says that the nitrogen is there to help the hardness. No mention of Nitride formation.

The focus of the Bohler Tech Data sheet is that this alloy can be hardened to ~57, giving it a good hardness for cutlery. It also says that it has good resistance to corrosion in chlorinated environments. Sea water is such an environment. It also says that it takes an exceeding fine edge. Alloys that don't form significant levels of carbides tend to have that property.

Today at work I talked about N680 to a metallurgist who specializes in stainless steels. I showed him the tech data sheet. I asked his opinion about nitride formation. His opinion is that it does not form the type of nitrides that would enhance abrasion resistance.

I can't comment on the actual edge retention performance because I've not tried N680. I will say that I've tried a number of other steels listed in this thread and strongly disagree with some of the rankings.

im no metallurgist, but it's my thinking that the nitrogen just takes the place that carbon would take in the crystalline structure (within the steel). high levels of carbon will easily combine with the chrome in the stainless steel while also forming martensite, but a lot of the chrome gets locked up in chromium carbide. this is good for wear resistance but not as good for corrosion resistance.

low carbon, high chrome steels are very corrosion resistant but tend to have lower hardness and resistance to wear. by adding nitrogen to make up for the lower levels of carbon, you can increase hardness (like it was a high carbon stainless steel) and still keep the corrosion resistance properties of the low-medium carbon stainless steel.

 

[Alpha Knife Supply]

The Bohler Tech Data sheet for N680 says that it forms fine carbides. So does 420HC. Fine carbides that do not appreciably improve abrasion resistance. To get significant amounts of the carbides that do increase abrasion resistance, you have to have above 0.77% Carbon.

The sheet also says that the nitrogen is there to help the hardness. No mention of Nitride formation.

The focus of the Bohler Tech Data sheet is that this alloy can be hardened to ~57, giving it a good hardness for cutlery. It also says that it has good resistance to corrosion in chlorinated environments. Sea water is such an environment. It also says that it takes an exceeding fine edge. Alloys that don't form significant levels of carbides tend to have that property.

Today at work I talked about N680 to a metallurgist who specializes in stainless steels. I showed him the tech data sheet. I asked his opinion about nitride formation. His opinion is that it does not form the type of nitrides that would enhance abrasion resistance.

I can't comment on the actual edge retention performance because I've not tried N680. I will say that I've tried a number of other steels listed in this thread and strongly disagree with some of the rankings.

Wow

If the datasheet does not specify an attribute it does not exist? When the datasheet does specify an attribute it must be the same as another steel? Asking someone for an opinion who is not familiar with the steel overrides the opinion of someone who specializes in the steel?

Hmm

Benchmade gets HRC58 from N680. That must mean the datasheet is wrong or Benchmade is lying. Or maybe Bohler under-promises and over delivers?

What about Vanax 35? It only has .20% carbon so it can't get hard according you your argument. However, I have test billets that are HRC59.5-60.0.

If you don't agree with Jim's results maybe you should post your own test results.

 

[knarfeng]

You misread my post. Where did I say that steel has to have a percentage of carbon or it can't get hard?

If your friend is an expert and knows cutlery steels as well as nitrogen steels then I will withdraw my comment and merely state that the only nitrogen steels that I have tried, H1 and 14C28N plainly do not form nitrides as they both have poor wear resistance.

I have posted my own results. You can find them if you search this subforum for threads started by me.
I would agree with Jim's results if they were posted as the results of the total knife and not just the steel.

 

[Folderguy]

You misread my post. Where did I say that steel has to have a percentage of carbon or it can't get hard?

If your friend is an expert and knows cutlery steels as well as nitrogen steels then I will withdraw my comment and merely state that the only nitrogen steels that I have tried, H1 and 14C28N plainly do not form nitrides as they both have poor wear resistance.

I have posted my own results. You can find them if you search this subforum for threads started by me.
I would agree with Jim's results if they were posted as the results of the total knife and not just the steel.

Clarification, please. What do you mean by your statement (bolded, in blue)?

 

[jimnolimit]

You misread my post. Where did I say that steel has to have a percentage of carbon or it can't get hard?

If your friend is an expert and knows cutlery steels as well as nitrogen steels then I will withdraw my comment and merely state that the only nitrogen steels that I have tried, H1 and 14C28N plainly do not form nitrides as they both have poor wear resistance.

i will also agree (until i find out otherwise). steels like H1, 14C28n or N680 are just substituting nitrogen for carbon in the martenistic crystalline structure of the stainless steel and not forming nitrides to aid in wear resistance. as i said before, these nitrogen steels are trying to mimic higher carbon stainless steel's hardness properties while being more corrosion resistant like low-med carbon stainless steels.

 

[knarfeng]

The cutting performance of a knife is not merely determined by the bevel and the sharpness. The rest of the blade geometry, and in particular the thickness of the blade just behind the bevel, make major contributions towards determining how much pressure it takes to make a cut. A measurement technique that is based on cutting pressure can only yield fully accurate results if the blade geometries are the same. Users like us do not have that luxury. So to me, the most we can say with a technique that is based on cutting pressure measurement is, "this knife, which has this blade steel, cut better than that knife, which has that blade steel".

As an example, Jim ranks VG10 as having the same performance as AUS8. Now, I've used a few VG10 blades for EDC. And I've got a few AUS8 blades that I've carried. Never in a million years would I consider their edge retentions to be equal. That has not been my experience with them using them on a daily basis, nor has it been the usage experience of anyone I know here on the boards.

But I might say that this KaBar Dozier, with its thinner blade, actually required less cutting pressure than that Spyderco Native, with its thicker blade geometry. But the superior performance of the Kabar is a function of its geometry, not its steel.

So if we were comparing knives and including the geometry in that, I'd be in 100% agreement with Jim's results. This knife cut about the same as that one. But I don't agree that the results are indicative purely of the performance of the alloy.

My issue is that I see some of the fellas stating absolutes in the General Forum such as "14C28N holds an edge better than VG10". Not in my experience, neither in testing nor in use. On the other hand, if they were to say, "Jim tested a 14C28N knife and it performed better than a Spyderco in VG10," That could absolutely be true. Useful information, too.

 

[Noctis3880]

Wow

If the datasheet does not specify an attribute it does not exist? When the datasheet does specify an attribute it must be the same as another steel? Asking someone for an opinion who is not familiar with the steel overrides the opinion of someone who specializes in the steel?

Hmm

Benchmade gets HRC58 from N680. That must mean the datasheet is wrong or Benchmade is lying. Or maybe Bohler under-promises and over delivers?

What about Vanax 35? It only has .20% carbon so it can't get hard according you your argument. However, I have test billets that are HRC59.5-60.0.

If you don't agree with Jim's results maybe you should post your own test results.

Hmm, technically nitrogen is said to be less prone to form nitrides as opposed to carbon forming carbides, though it's been said that you can still achieve a high volume of nitrides with modern technology. I don't know if that means that the steel must be a PM steel as a prerequisite.

But generally when nitrogen is added in small amounts, the goal is to increase hardness without increasing the carbide volume.

 

[JNewell]

im no metallurgist, but it's my thinking that the nitrogen just takes the place that carbon would take in the crystalline structure (within the steel). high levels of carbon will easily combine with the chrome in the stainless steel while also forming martensite, but a lot of the chrome gets locked up in chromium carbide. this is good for wear resistance but not as good for corrosion resistance.

low carbon, high chrome steels are very corrosion resistant but tend to have lower hardness and resistance to wear. by adding nitrogen to make up for the lower levels of carbon, you can increase hardness (like it was a high carbon stainless steel) and still keep the corrosion resistance properties of the low-medium carbon stainless steel.

Can you clarify how you arrived at the conclusion below?

i will also agree (until i find out otherwise). steels like H1, 14C28n or N680 are just substituting nitrogen for carbon in the martenistic crystalline structure of the stainless steel and not forming nitrides to aid in wear resistance. as i said before, these nitrogen steels are trying to mimic higher carbon stainless steel's hardness properties while being more corrosion resistant like low-med carbon stainless steels.

 

[Ankerson]

The cutting performance of a knife is not merely determined by the bevel and the sharpness. The rest of the blade geometry, and in particular the thickness of the blade just behind the bevel, make major contributions towards determining how much pressure it takes to make a cut. A measurement technique that is based on cutting pressure can only yield fully accurate results if the blade geometries are the same. Users like us do not have that luxury. So to me, the most we can say with a technique that is based on cutting pressure measurement is, "this knife, which has this blade steel, cut better than that knife, which has that blade steel".

As an example, Jim ranks VG10 as having the same performance as AUS8. Now, I've used a few VG10 blades for EDC. And I've got a few AUS8 blades that I've carried. Never in a million years would I consider their edge retentions to be equal. That has not been my experience with them using them on a daily basis, nor has it been the usage experience of anyone I know here on the boards.

But I might say that this KaBar Dozier, with its thinner blade, actually required less cutting pressure than that Spyderco Native, with its thicker blade geometry. But the superior performance of the Kabar is a function of its geometry, not its steel.

So if we were comparing knives and including the geometry in that, I'd be in 100% agreement with Jim's results. This knife cut about the same as that one. But I don't agree that the results are indicative purely of the performance of the alloy.

My issue is that I see some of the fellas stating absolutes in the General Forum such as "14C28N holds an edge better than VG10". Not in my experience, neither in testing nor in use. On the other hand, if they were to say, "Jim tested a 14C28N knife and it performed better than a Spyderco in VG10," That could absolutely be true. Useful information, too.

There are no concrete end all beat all answers when talking about steels.

I use words like around, could be, that's possible and I don't know a lot because of this.

That's another reason why I don't rank them in order from best to last because that's just not really possible without a CATRA machine and even then there are still variables to consider like the steels themselves can vary even within the same piece of steel.

In the end NONE of us really know because we are all students and the steels are the teachers, not the other way around.

When on the topic of steels the more we learn the more we realise we don't know anything because it's a constant learning process.

I mentioned this in the 1st post of this thread, that being there are no concrete answers or end all beat all answers and stated that I am not ranking them from best to last and the purpose of the categories.

So if people are misrepresenting my results point them to that part in the 1st post in the thread.

 

[JNewell]

Personally, it never occurred to me to test knives on concrete.

 

[STR]

The cutting performance of a knife is not merely determined by the bevel and the sharpness. The rest of the blade geometry, and in particular the thickness of the blade just behind the bevel, make major contributions towards determining how much pressure it takes to make a cut. A measurement technique that is based on cutting pressure can only yield fully accurate results if the blade geometries are the same. Users like us do not have that luxury. So to me, the most we can say with a technique that is based on cutting pressure measurement is, "this knife, which has this blade steel, cut better than that knife, which has that blade steel".

As an example, Jim ranks VG10 as having the same performance as AUS8. Now, I've used a few VG10 blades for EDC. And I've got a few AUS8 blades that I've carried. Never in a million years would I consider their edge retentions to be equal. That has not been my experience with them using them on a daily basis, nor has it been the usage experience of anyone I know here on the boards.

But I might say that this KaBar Dozier, with its thinner blade, actually required less cutting pressure than that Spyderco Native, with its thicker blade geometry. But the superior performance of the Kabar is a function of its geometry, not its steel.

So if we were comparing knives and including the geometry in that, I'd be in 100% agreement with Jim's results. This knife cut about the same as that one. But I don't agree that the results are indicative purely of the performance of the alloy.

My issue is that I see some of the fellas stating absolutes in the General Forum such as "14C28N holds an edge better than VG10". Not in my experience, neither in testing nor in use. On the other hand, if they were to say, "Jim tested a 14C28N knife and it performed better than a Spyderco in VG10," That could absolutely be true. Useful information, too.

Good points but little mention of blade coatings or finishes in this thread. This certainly contributes to perceived effort at times when using a knife that could translate as edge holding or blade geometry issues when it may be that the finish or the coating inhibits performance or adds to it as the case may be. Therefore two identical blades, ie same blade geometry and edge angle/sharpening technique but one dura coated and the other mirror polished may seem entirely different in use.

STR

 

[michaelm466]

Ankerson: any plans to test your 3V Strider? Just watched your youtube video for it, I'd be interested to see how that one does.

 

[Ankerson]

Ankerson: any plans to test your 3V Strider? Just watched your youtube video for it, I'd be interested to see how that one does.

The black oxide coating is very abrasive so I will have to wait until it smooths out a lot.