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

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. :thumbup:

STR

 

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

 

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

 

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?

 

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

 

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.

 

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

 

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

 

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

 

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

 

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

 

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!