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

[Ankerson]

What I have done is rank the steels in Categories based on edge retention cutting 5/8" manila rope. We are looking for big differences here, not ranking the steels in order such as 1,2,3,4,5. The categories or groups mean that one can expect those steels in that category to have close to the same performance as the other steels in the same category. The categories are ranked in order by edge retention, category 1 will have better performance than category 2 etc.

The Custom Phil Wilson knives in M390 (62) and ELMAX (62) are not added to the data, they wouldn't fit into any of the Categories due to the Optimal HT and cutting ability, the difference is off the scale percentage wise so it wasn't added.

The Testing Process is as follows:

Cutting 5/8" Manila rope on a Scale with wood to cut on. The scale was calibrated for the weight of the wood. Making 3 to 4 slicing cuts from back to tip using the least amount of down force needed to get the starting down force. Once that was established 20 cuts were made then down force was tested again and that continued until 20 LBS was reached.

All the knives started at 14 ~ 15 LBS of down force except for M390 because it cuts so aggressively.

Accuracy is to + or - 10 Cuts and + or - 1 LB of down force or 6%. This was verified doing a blind test of blades of unknown hardness until they were tested after. 2 blades of the same hardness and steel, sharpened the same and same model of knife.

RC hardness is + or - 1 RC on the steels that were tested as the standard of RC testing.

All edges were at 30 degrees inclusive and polished to 6000 grit on the Edge Pro, sharpness was tested by slicing TP clean.

The following data is the results that I got based on the above method, while not conclusive or the end all beat all data it is very accurate.

More steels will be added as they are tested.

Category 1

CPM-S90V (Military and Para 2) (60)
CTS-20CP (Para 2) (60)
M390 (Mule) (60.5)

Category 2

M390 (60)
CPM M4 (62.5)
CPM-S90V (59) (Manix 2 with 30 Degree Micro Bevel)
CPM-S60V
VANAX 75 (Kershaw Tilt)

Category 3

Vanax 35 (59.5)


Category 4

ZDP-189 (65)
CPM-154 (62)
ELMAX (60)
CTS-XHP (Military) (60+)
Super Blue (61.5)
CPM 3V (Big Chris)


Category 5

S30V (60)
VG-1
CPM - D2 (62)
N690
ATS-34 (59)
CPM-S35VN (59)
N680
ELMAX (58.5) Mule
D2 - Dozier K2

Category 6

INFI
154CM (61)
14C28N

Category 7

VG-10
S30V (58.5)
AUS-8A
SG-2
5160 (55)
13C26N
X-15
440C (Big Chris)

Category 8

H-1
420 HC (Buck 110)

Category 9

CTS-BD1

[STR]

I expect that over time category 5 will grow as you branch out and that the other categories will end up being the smaller ones particularly the two top ones.

In my mind I can kind of imagine where some would probably end up but they may surprise. One has to wonder, where would 420HC, 13C26/14C28 and 12C27 be? Or 1095, (CV and all equivalents) 3V and other carbon steels. Then with some steels you would almost have to have sub categories for hardness. 1095 for example can be 62 RC or 56 RC and perform fine at both or anywhere in between for various purposes. I'm sure each one at various hardnesses would do differently in your testings. Anyway, its some good info. I think you'll find some are surprised at AUS8 being in the same league as S30V but personally I'm not at all surprised. I remember someone saying that when they tested SG2 it only performed like AUS8 as if that was a bad thing. I've always known AUS8 (Note: Real AUS8) was a fine average steel that in many ways is the better choice among the other average steels available including SG2. I've never understood all the negative press AUS8 gets as if its a bad steel. Been saying that for years.

Your tests kind of proves that out.

STR

[Ankerson]

I expect that over time category 5 will grow as you branch out and that the other categories will end up being the smaller ones particularly the two top ones.

In my mind I can kind of imagine where some would probably end up but they may surprise. One has to wonder, where would 420HC, 13C26/14C28 and 12C27 be? Or 1095, (CV and all equivalents) 3V and other carbon steels. Then with some steels you would almost have to have sub categories for hardness. 1095 for example can be 62 RC or 56 RC and perform fine at both or anywhere in between for various purposes. I'm sure each one at various hardnesses would do differently in your testings. Anyway, its some good info. I think you'll find some are surprised at AUS8 being in the same league as S30V but personally I'm not at all surprised. I remember someone saying that when they tested SG2 it only performed like AUS8 as if that was a bad thing. I've always known AUS8 (Note: Real AUS8) was a fine average steel that in many ways is the better choice among the other average steels available including SG2. I've never understood all the negative press AUS8 gets as if its a bad steel. Been saying that for years.

Your tests kind of proves that out.

STR

I will group them in the categories by their hardness and performance like I did with S30V, I have it in 2 categories at different hardness, both 58 and 60 RC.

As I add more steels it will get even more interesting over time.

[The Mastiff]

That two points of hardness makes such a difference in a high quality steel is going to come as a surprise to some. It's something I've felt for years but had nothing subjective to prove it. I can even feel it on the stones when sharpening.

Some like M2 might jump two categories if you test one at Rc 58-59, then test a full hardness blade. We'll see. It will be fun watching this one develop. Jim, good work as usual. Joe

[Ankerson]

That two points of hardness makes such a difference in a high quality steel is going to come as a surprise to some. It's something I've felt for years but had nothing subjective to prove it. I can even feel it on the stones when sharpening.

Some like M2 might jump two categories if you test one at Rc 58-59, then test a full hardness blade. We'll see. It will be fun watching this one develop. Jim, good work as usual. Joe

Yeah there can be a huge difference in 2 points of hardness depending on the steel as I found out.

As I add more steels to the categories hopefully we will also see them at different hardness so they can be put into the different categories based on performance at different hardness.

[STR]

Yeah there can be a huge difference in 2 points of hardness depending on the steel as I found out.

As I add more steels to the categories hopefully we will also see them at different hardness so they can be put into the different categories based on performance at different hardness.

I don't know. I think I see/experience differences in various 1095 blades from production company to production company too. I don't know the hardness but its obvious to me that my Marbles or rather tang stamped MSA 01 Tear Drop Buffalo slippie is a much harder blade and much better edge keeper than my Old Timer 80T or my Case CV knives. All are the same steel but that MSA will cut circles around the Case knives and is also better than the OT which is slightly better than the Case MF hunter. It appears that two points on the RC scale can be a much bigger difference than it may seem. Once again your S30V observations seem to prove out what I've felt was going on in my own mind for some time but could never really prove in any way to make it worth bringing up.

From the stand point of what is a good steel and what is a great steel I'd have to say that these kind of issues where we see + or - differences and various heat treat problems give the steel a lesser rating at least in my mind. I mean S30V may be the better steel on paper or in theory over 154CM but 154CM is a very trouble free steel you rarely if ever hear anything bad about. It seems to work for a lot of folks consistently so I'd give it the edge over S30V as a better choice just for these reasons and not just over S30V but over SG2, VG10 and BG42 also again for similar reasons having to do with either heat treat pickiness, availability, price differences and so on.

STR

[hardheart]

The Rockwell C scale is essentially logarithmic, a couple of points is a rather large difference and should definitely be seen in test cutting

What is the spread in the number of cuts in each category?

[Ankerson]

I don't know. I think I see/experience differences in various 1095 blades from production company to production company too. I don't know the hardness but its obvious to me that my Marbles or rather tang stamped MSA 01 Tear Drop Buffalo slippie is a much harder blade and much better edge keeper than my Old Timer 80T or my Case CV knives. All are the same steel but that MSA will cut circles around the Case knives and is also better than the OT which is slightly better than the Case MF hunter. It appears that two points on the RC scale can be a much bigger difference than it may seem. Once again your S30V observations seem to prove out what I've felt was going on in my own mind for some time but could never really prove in any way to make it worth bringing up.

From the stand point of what is a good steel and what is a great steel I'd have to say that these kind of issues where we see + or - differences and various heat treat problems give the steel a lesser rating at least in my mind. I mean S30V may be the better steel on paper or in theory over 154CM but 154CM is a very trouble free steel you rarely if ever hear anything bad about. It seems to work for a lot of folks consistently so I'd give it the edge over S30V as a better choice just for these reasons and not just over S30V but over SG2, VG10 and BG42 also again for similar reasons having to do with either heat treat pickiness, availability, price differences and so on.

STR

That's what I ment, if the hardness difference changes the performance to the point that it will move it into another category, also I might have too add another category at some point based on the cutting data between categories 3 and 4.

[Bartonj]

on your vid of the cts-bd1 mule the edge retention looked great vs the cardboard box

[GrinderMcgee]

Thank you for your time and work invested in creating the criteria and standard test for your blades Jim. The information is quite interesting and valuable.

To me, good is good, and is easily seen in use, although I admit ease of sharpening is a major factor for my blade choice and that turns me off to some of the higher hardness steels that seem to be performing well in retention.

One of my favs not on the list currently is ATS 34, perhaps that will make the cutting board someday also.

[Ankerson]

Thank you for your time and work invested in creating the criteria and standard test for your blades Jim. The information is quite interesting and valuable.

To me, good is good, and is easily seen in use, although I admit ease of sharpening is a major factor for my blade choice and that turns me off to some of the higher hardness steels that seem to be performing well in retention.

One of my favs not on the list currently is ATS 34, perhaps that will make the cutting board someday also.

I need to get some suitable blades to test in other steels, something around 3.5 " to 4" seem to work best and they can't be to thick as I need to keep the starting force in the 14 to 15 LB range.

[PatriotDan]

This and the polish edge test are your best tests so far in my opinion. Good work!

[Ankerson]

This and the polish edge test are your best tests so far in my opinion. Good work!

Thanks, we wanted it to be as accurate as possible within the variables and be repeatable and consistant.

[gunmike1]

Great test! I really like how you sorted the steels by group, as the margin of error in any test makes it almost impossible to rank steels as an absolute 1, 2, 3 manner, at least in my opinion and experience. Also, I have noticed a big difference in some steels due to the hardness on the stones and also in edge retention, so I like how you have S30V in two different categories based on the hardness. For instance it was nothing I could really quantify, but I know in my use Spyderco's M4 outperforms Benchmade's M4. Spyderco's M4 is just better in taking and holding an edge in my experience.

I know you have put in countless hours to do this test, but I have plenty of knives to test if you ever have the time or inclination to test some of my blades. I have a 154CM Benchmade Rift that is thin at the edge (and grind) for a production knife that was tested at 61 RC, I think that would be nice to see where it groups out at. I also have a 62 RC CPM D2 Spyderco Military that performs excellent. I find the CPM D2 Millie to be better than 59 RC S30V, so that might be good to test. I also think that the Rift's 154CM blade at 61 RC gives up nothing to S30V at 59 RC. I have several other knives that if you ever get the time I think would be good to test and see how they compare to the other steels you have done. Another interesting thought is how 2 blades made of the same steel at the same hardness compare, as there are lots of different ways in the heat treat to reach the same hardness with different properties in the steel. My Manix is S30V at 58 RC, but for me it takes a better edge and holds it longer than my S30V Native at 59 RC. By all logic I would have expected the harder S30V to outperform the Manix, but my impressions, which of course aren't quatified, are that the Manix works better than the Native. I was really surprised when the blades were tested that the Manix was 58 RC, I thought for sure it was around 60 RC and definately thought it was harder than the Native. The Rockwell tester showed a different story, though.

Thanks again for all of your hard work, I hope your arms and body aren't suffering too bad from all of that cutting. Again, if you ever get the inclination or time I have many blades in different steels that are already tested for hardness, and the rest are on their way to be tested. They were also tested by the same machine that tested your knives, so that should be a good apples to apples hardness if you ever do get the time or want to test out any of my knives.

Mike

[DennisStrickland]

thanks jim for all this info & hard work. i've read that for every 2 points increase in the rockwell that the edge endurance gains 20%. some members suggested on the newer alphabet alloys that the pecentage gain for the edge endurance with 2 more ppints rockwell may be more than 20%. it looks as if you guys will eventually validate that info. of course it would be much more difficult if this figure was'nt a constant. as in 1095 going from 56 to 58 & only getting a 12% increase in endurance while cpm154 going from 60 to 62 & getting a 25% edge endurance increase.anyway that's for another day.
dennis

[knarfeng]

I know we have discussed this offline, and perhaps it is indeed due to the fact that you use polished edges and I do not, but my results don't altogether match yours.

I typically use DMT stones starting at extra coarse and up to extra Fine at 15° per side. So, IIRC, that means I stop at 1200 grit.

Like you, I cannot differentiate between M390 and CPM M4 HC. And they greatly outperform everything else,
But...

• I have tested VG 1 and VG 10, both measured at a 59 Rockwell and cannot tell them apart.
  
• I have tested S30V at 58. It easily outperformed VG 10 at 59.
  
• When I tested AUS8 at 59, it was easily outperformed by 440C, 154CM, VG10, S30V all at 58 or 59.

Now the conclusion to be drawn may be that a polished blade edge with few carbides will outperform a polished blade edge that has a bunch of carbides. Certainly Thombrogan or razorsharp244 (field engineer for Sandvik Steel) would agree. That is the general Sandvik philosophy.

However, I think that most folks don't use knives with polished edges, so their results may not match yours. My own field experience does not match your results, but then I don't use polished edges in my daily usage any more than when I test.

But I find the results fascinating. And I thank you for posting them.

[Ankerson]

Great test! I really like how you sorted the steels by group, as the margin of error in any test makes it almost impossible to rank steels as an absolute 1, 2, 3 manner, at least in my opinion and experience. Also, I have noticed a big difference in some steels due to the hardness on the stones and also in edge retention, so I like how you have S30V in two different categories based on the hardness. For instance it was nothing I could really quantify, but I know in my use Spyderco's M4 outperforms Benchmade's M4. Spyderco's M4 is just better in taking and holding an edge in my experience.

I know you have put in countless hours to do this test, but I have plenty of knives to test if you ever have the time or inclination to test some of my blades. I have a 154CM Benchmade Rift that is thin at the edge (and grind) for a production knife that was tested at 61 RC, I think that would be nice to see where it groups out at. I also have a 62 RC CPM D2 Spyderco Military that performs excellent. I find the CPM D2 Millie to be better than 59 RC S30V, so that might be good to test. I also think that the Rift's 154CM blade at 61 RC gives up nothing to S30V at 59 RC. I have several other knives that if you ever get the time I think would be good to test and see how they compare to the other steels you have done. Another interesting thought is how 2 blades made of the same steel at the same hardness compare, as there are lots of different ways in the heat treat to reach the same hardness with different properties in the steel. My Manix is S30V at 58 RC, but for me it takes a better edge and holds it longer than my S30V Native at 59 RC. By all logic I would have expected the harder S30V to outperform the Manix, but my impressions, which of course aren't quatified, are that the Manix works better than the Native. I was really surprised when the blades were tested that the Manix was 58 RC, I thought for sure it was around 60 RC and definately thought it was harder than the Native. The Rockwell tester showed a different story, though.

Thanks again for all of your hard work, I hope your arms and body aren't suffering too bad from all of that cutting. Again, if you ever get the inclination or time I have many blades in different steels that are already tested for hardness, and the rest are on their way to be tested. They were also tested by the same machine that tested your knives, so that should be a good apples to apples hardness if you ever do get the time or want to test out any of my knives.

Mike

The D2 Military and the 154CM blade would be great additions for sure.

I did test 2 exact blades at the same hardness and same steel and they were within 10 cuts of each other.

I know we have discussed this offline, and perhaps it is indeed due to the fact that you use polished edges and I do not, but my results don't altogether match yours.

I typically use DMT stones starting at extra coarse and up to extra Fine at 15° per side. So, IIRC, that means I stop at 1200 grit.

Like you, I cannot differentiate between M390 and CPM M4 HC. And they greatly outperform everything else,
But...

• I have tested VG 1 and VG 10, both measured at a 59 Rockwell and cannot tell them apart.
  
• I have tested S30V at 58. It easily outperformed VG 10 at 59.
  
• When I tested AUS8 at 59, it was easily outperformed by 440C, 154CM, VG10, S30V all at 58 or 59.

Now the conclusion to be drawn may be that a polished blade edge with few carbides will outperform a polished blade edge that has a bunch of carbides. Certainly Thombrogan or razorsharp244 (field engineer for Sandvik Steel) would agree. That is the general Sandvik philosophy.

However, I think that most folks don't use knives with polished edges, so their results may not match yours. My own field experience does not match your results, but then I don't use polished edges in my daily usage any more than when I test.

But I find the results fascinating. And I thank you for posting them.

The reason I use the polished edges is so it takes out another variable, differences in sharpening and it's easy to compare sharpness between the blades. Having a strict sharpness test like I do only increases the accuracy of the testing process. All the knives are sharpened to measured 30 degrees inclusive on the same EP and to the same sharpness. That takes out 2 huge variables right there, all the steels start out on an even plane. That is verified by the consistency of the starting downward force between the steels. We also have the same stopping downward force on all steels at 20 LBS.

Also using the polished edges means the steels will cut longer so we have a more definite sharpness curve. All the polished edges do is make the edges stronger so they cut longer before edge breakdown.

That's why I can say it's as accurate as it is, but as with any testing process it's not perfect, not even the CARTA is perfect.

Also I am not ranking the steels in order, I am putting them into categories by edge retention based on the number of cuts to reach 20 LBS, we are looking for the big differences.

[DennisStrickland]

jim's polished edges got me to buy an edge pro. now a lot can be achived with belt machines & green rouge but the angle even with a jig ca'nt be held to as exact an angle as on the edge pro. however i'm working with belts on a 20 yr. old lo-ray.the polished edges just glide thru tough cardboard. one trick i've learned is after going all the way to 6000 polish tape using the glass tape holder is to take the blade back to the spydie fine hone & drop the cutting edge back a little bit. in other words dull the super sharp edge back a coupal of points. what i end up with is mirror polished bevels with a real sharp working edge. i do this so if i hit bones going thru hogs or deer i lessen chip possibilty. this edge gives the advantage of friction reducing bevels which are mirror polished but the exact cutting edge is'nt quite as delicate. people with steadier hands probably do'nt have this worry.
dennis

[STR]

If the edge stays true longer because its stronger with less frayed ends and jagged edges it would make sense that you could get a better idea of just what each steel is capable of when as close to ideal as you can get it but even two edges from two different knives taken to the same exact bevel angle and done to the same grit will have various differences in primary grind geometry that can also affect the way they cut as well as edge strength. One other thing I've noticed is the finish also. I've always believed that a high finish like that Phil does on his knives you posted earlier make it that much easier for a blade to slice through things as opposed to one just bead blasted or left rather course finished by comparison. I'm sure the differences are nil but the point is there would probably be difference in even two of the same blades with one finished out and the other not. How to prove that is another thing altogether but it could probably show up in a test like you are running Jim.

While a high polish may make the edge stronger I agree that its not really optimum for a lot of things people do on a daily basis. Push cutting is great for carving wood but you aren't really going to need it for slicing rags or cutting out an old radiator hose from your 1955 IHC pickup truck. Okay, my 1955 IHC truck!

STR

[sodak]

I'm actually a little bummed that ZDP didn't do even better than the others, especially given the hardness. It's pretty much kicked all of my other knives out of my pocket for EDC, I've been really enjoying it in my Caly's. Oh well, I love to see these results, even if they aren't what I was expecting.

That's what makes this fun, you gotta have an open mind!