Some Rockwell testing results

gunmike1

gunmike1

Gold Member
Joined
Dec 9, 2005
Messages
2,402
I had a few Spydercos Rockwell tested and they all were very good.

Stretch 2 CF ZDP 189: 64.5 RC
M4 Mule: 62.5 RC
CPM D2 Millie: 62 RC (now I know why I love this knife so much)
Manix 2 S90V: 58-59 RC

The Manix 2 had a wide spread on the points tested (on the flats near the handle) from 56-59.5 RC. Curious as the others tested consistently and the machine and person doing the testing are dialed in. Maybe some grinding after the heat treat drew the temper just a tad? Who knows, I just know in my limited experience with it the steels cuts very well. That is odd to get a huge spread in hardness values though.

I am very pleased with the hardness of the Stretch 2 and M4 Mule, they are pretty much right where I thought they would be. The CPM D2 Millie was a good point harder than I thought it might be, but I have always loved how crisp that knife sharpened up and it's edge retention compared to S30V, and being 3-4 points harder than any of my S30V blades explains a lot in why it is such an excellent performer. Now we need Sal to try some CPM 154 at 62 RC and we might be in for a real treat as well.

I think these results speak very well for Spyderco's heat treating, which I have come to expect. The knives I sent all sharpen up very crisply on the stones with minimal burring, and whatever recipe Spyderco's heat treaters are using for the steels is working very well. The consistency from knife to knife is impressive as well, as from prior testing most all of my VG-10 is 59 and the same with S30V (except my great Manix, my best performer in S30V despite being 58 RC). I will soon get my ZDP Mule tested to see if Spyderco pushed the limit higher with the hardness.

Mike
 
Thanks for the info, very interesting.

I was a little surprised about the S90V, I thought it should be harder. I guess as proven with your S30V Manix, hardness isn't everything.:)
 
Interesting test results! Especially the 62 on the CPM D2 and the M4 Mule test results.
 
We know the carbides in S90V are tough, maybe the relative softness of the surface (not the sharpened edge of course) are low, but at the edge and where ground in the carbides create a hard strong edge.

Just speculation.
 
Great thread Mike. Thanks. Spyderco has always been about as consistent as a production company can be. I don't know enough about things to explain the variation in the S90V blade. Were the other ones tested as many times as the Manix? Some variation in steel is expected, but the values seem pretty large for a small, relatively thin folder blade. Perhaps someone that heats S90V can chime in. Perhaps ask Sal, or someone who does S90V himself like Phil Wilson. He has a greater understanding of the crucible than most, and a willingness to share his knowledge.

I wouldn't call it a problem if it was my knife until I saw performance issues, but it is a thing that I'm curious about.
 
I think the S90V might not have been soaked long enough during austenization but it's pure speculation on my part.

I'm glad to see Spyderco's CPM M4 a lot harder than Benchmade's CPM M4 though, and much cheaper.
 
The Mastiff said:
Great thread Mike. Thanks. Spyderco has always been about as consistent as a production company can be. I don't know enough about things to explain the variation in the S90V blade. Were the other ones tested as many times as the Manix? Some variation in steel is expected, but the values seem pretty large for a small, relatively thin folder blade. Perhaps someone that heats S90V can chime in. Perhaps ask Sal, or someone who does S90V himself like Phil Wilson. He has a greater understanding of the crucible than most, and a willingness to share his knowledge.

I wouldn't call it a problem if it was my knife until I saw performance issues, but it is a thing that I'm curious about.
Click to expand...

I would love if Sal could chime in on the S90V results as well. Phil Wilson did the testing and we really couldn't come up with an answer except possible grinding after heat treating possible causing the variance. It was tested on the flat near the handle of the knife, and from what he said he ran several test points but didn't want the whole knife covered in RC testing marks. At the edge it seems fine after how it performed for me in the limited time I've had it before mailing it off for testing. I don't want to put words in Phil's mouth, so if he wants to talk about it that would be great, but it is really hard to speculate what would cause the variance in the S90V. Again, as long as it performs well at the edge I'm not worried and have to assume it is fine, but without a known S90V test blade to compare it to I might not be getting the performance out of S90V that I shoud be. Either ignorance is bliss with this one or the heat treat is fine. Maybe a re-heat treat to 60-61 is in order now, or more accurately I might have found an excuse to re-heat treat it.

The hardness of the CPM D2 was a little surprising to me but I was guessing it was around 60.5-61 RC due to it's great qualities of taking a fine edge and holding it a long time. I really like that steel, but from what I've heard CPM154 is an even better performer and more stainless to boot. It would be cool to see a CPM154 Millie at 62 RC.

The Mule in M4 seemed just like my Krein M4 Ultimate Caper on the stones, so I guessed it would be in the same hardness range (62-63) and was right. The Stretch 2 CF is 1.5 RC points harder than my ZDP Endura. From sharpening the Stretch seems to burr slightly less (actually the Stretch barely burrs at all and Endura only burrs slightly, it's not like the Endura is hard to sharpen due to burring, far from it) and get a tad sharper, and the Stretch 2 is less tolerant of ceramic stones than the Endura (I've had very hard steels microchip on ceramics), so it makes sense it's a bit harder. The Endura is a great performer as well, especially after a Krein regrind, but the Stretch 2 is just a tad crisper on the stones. It will be interesting to see the hardness of the ZDP Mule once I get mine back from Tom Krein to see if it is a bit harder than the Stretch 2. I only did a quick look over on my Mule before mailing it out (it was tree topping arm hairs effortlessly and probably whittled hair) so I can't really comment on how it sharpens yet.

The thing I got out of this test and the previous RC testing done on my Spydercos is that they have consistently good heat treatments on their knives. They all have performed very good for me. I'm sure there is an explanation for the Manix 2's results, but I will take the 58-59 RC estimate and go with that until I get any type of performance that would suggest any problems with the heat treat. So far the steel has acted as I expected: excellent wear resistance and not wanting to take a super polished edge like M4. I really doubt I'll see any problems, though it would be nice to know why the variance was so high on the testing. My guess is I may never know why the variance was so big on such a tiny test area of steel.

Mike
 
Mike and others. A little more info on the Manix-- S90V. I always do at least 3 tests and average them. I also do a calibration check before and after. I did get one spot at 58 and another at 59. The 56 as we say was a flier. Could be the machine, the operator, or in fact hit a soft area in the steel. I would not worry about it. Two at 58, 59 tells me that the 56 is not real. I can't measure the blade itself since we have to have a flat spot to get a true reading. Also keep in mind that I am showing readings to 0.5. The test block is only good to 0.5 and the machine to another 0.5 so depending on how they add up or subtract there could be at least 1 point variance. I know the machine so feel like I can get a little closer and as a result have confidence in going to half a point. 58/59 on CPM S90V is good heat treating. This is the most difficult steel out there to heat treat (IMHO) and Spyderco hit it on the nose. Phil
 
Thanks for clarifying it, Phil. Sorry if I misrepresented anything, I just remember that there was the one low reading of 56 which was a bit odd but that you were comfortable calling it 58/59 due to the other points tested. I should have e mailed you before posting my last response to let you completely speak for yourself without me putting words in your mouth or mis-representing your words and thoughts on that knife. I remember you mentioning possible reasons a steel could have a low reading along with the higher ones, with the possibility of grinding after the heat treat being one, but obviously that was one of a host of possibilities that could cause that to happen, and as you said it could have been and probably was a flyer. I do remember you praising Spyderco's heat treating and I was going to e mail you about this thread to see if you wanted to jump in, and I apoligise for not e mailing you first. I know nothing in the knife's performance is anything but excellent, and I really appreciate you sharing of your great knowledge and experience with knives with the rest of us in the seek of more knowledge. Thank you again for your help and sorry for any misunderstanding.

Mike
 
Nice, thanks for the info, I can tell a difference when sharpening
the ZDP verses the S30v as well, love that ZDP ;)
but the S30v is no slouch either!
G2
 
Very nice. :thumbup:

Would love to see some pix showing the test marks.

I wouldn't worry too much about the "minority report", pair of deuces beats an ace.
 
Thanks for clarifying it, Phil. Sorry if I misrepresented anything, I just remember that there was the one low reading of 56 which was a bit odd but that you were comfortable calling it 58/59 due to the other points tested. I should have e mailed you before posting my last response to let you completely speak for yourself without me putting words in your mouth or mis-representing your words and thoughts on that knife. I remember you mentioning possible reasons a steel could have a low reading along with the higher ones, with the possibility of grinding after the heat treat being one, but obviously that was one of a host of possibilities that could cause that to happen, and as you said it could have been and probably was a flyer. I do remember you praising Spyderco's heat treating and I was going to e mail you about this thread to see if you wanted to jump in, and I apoligise for not e mailing you first. I know nothing in the knife's performance is anything but excellent, and I really appreciate you sharing of your great knowledge and experience with knives with the rest of us in the seek of more knowledge. Thank you again for your help and sorry for any misunderstanding

Mike no problem, you did not misrepresent any thing. I just wanted to add a little more information. Phil
 
Phil, thanks again for the sharing of your knowledge with the rest of us on the forums. Your vast knowledge and real world testing and experience are a huge resource that us steel junkies love to hear about. I think it is fair to say you have more knowledge and experience with getting the absolute best cutting performance out of the CPM steels, especially the more exotic steels like S90V, 10V, S110V, and S125V. I know I always look forward to your posts because I am sure to learn something.

Mike
 
Gary W. Graley said:
Nice, thanks for the info, I can tell a difference when sharpening
the ZDP verses the S30v as well, love that ZDP ;)
but the S30v is no slouch either!
G2
Click to expand...

I recently rebeveled a couple Krein regrinds, one in S30V, the other in ZDP, by about 4 degrees per side on each knife. It took about 50% longer on the ZDP 189 knife to get the new bevel set. That gives a good idea about the extra wear resistance of ZDP 189. It is funny to me now when I read about how hard it is to sharpen S30V or D2, or even ZDP 189, because my diamonds just blast through any steel, the exotic ones like ZDP and S90V just take a bit longer. A .010" or thinner edge really helps shorten your sharpening time, but DMT's on the coarse grits really make it quick and easy to sharpen any steel, likewise with my Shapton Glasstones on the finer grits.

Back to your original point, S30V can be a great performer when heat treated right, like my Manix which is a top notch performer. My Millies proved to me though that CPM D2 was a better performer (the extra 3 points of hardness probably account for a big part of that difference), so my Dad has the S30V one and passes it around with his friends for spreading just how good a knife the Millie is. My dad's carry knives are a Civilian, P'kal, and a Small Sebbie re-heat treated by Phil Wilson to 60.5 RC and reground by Tom Krein. He goes to eat in a high crime area, so he carries the SD knives, and mainly cuts with the Sebbie that really cuts like a champ. The extra hardness over stock makes a big difference in how the steel acts, and of course the regrind makes it cut real nice. S30V isn't on my favorite steels list, but there is no doubt it can be an excellent steel when Spyderco or Phil Wilson get their hands on it. As nice as the Sebbie is my Spydercos in S30V have had better sharpness and edge retention than the 2 Sebbies with factory heat treats I have used, leading me to believe the Spyderco heat treat is better for getting more of the potential out of the steel. Whoever Spyderco gets for their heat treat is pretty darned good in keeping the RC spreads low and the performance high in all of their steels, another reason to like Spyderco on top of the great ergos and designs.

Mike
 
Would it be possible to test another Spyderco in S90V like a Millie or a Mule to see if the same readings are achieved?
 
Just as a follow up, Phil tested 2 more spots on the knife and got 58 and 58.5, so it appears Spyderco really got a pretty much perfect heat treat on this one for high toughness and excellent wear resistance. That 56 may have been on a slightly rough spot that could have had the tester slip, and all of the other readings are looking like Spyderco got a 58-59 RC blade. In S90V that leaves excellent wear resistance along with very good for the steel toughness, which is pretty important in a knife like the Manix 2 that just begs to be used hard. My knife now has a lot of little dents in it, but that is fine with me since it pretty much settled the issue of the low reading being a "flyer" and that the knife has a pretty optimal heat treat. Sure, it could be taken harder by a point or two, but at the expense of toughness and people complaining about chipping if they do twisting cuts (not to mention having to do a much more involved heat treat), so I am very pleased with the readings. The moral of the story is that Spyderco nailed the heat treat and I let that flyer reading become an issue where in reality it real isn't an issue. The knife cuts very nicely and sharpens up very good, so I am very happy with it.

A side note is after talking to Phil about how the polished edge cut rope I will probably go with a toothy edge on this knife. It bit into rope great when pushing but took a lot of effort to slice with on the rope, so I will be going with a coarser edge to optimize slicing with it. Since it pops hairs at DMT Coarse, I could leave it there and have excellent slicing performance, though Phil recommended going to DMT X-fine and lightly stropping off the burr for optimal performance, so I will definately try that. I did notice when skinning a pig with my M4 Mule it actually performed better once it had worn some and the edge got a bit toothy. That corresponds with my earlier experiences of getting excellent performance on rope and game with DMT fine and Spyderco fine finishes. A .05 micron edge is great for push cutting things, but isnt optimal for pure slicing cuts like you encounter when processing game. Spyderco, Tom Krein, and Phil Wilson all use toothy edges that are very impressive push cutters as well, and that would seem to be optimum for processing game or other pure slicing cuts. That is no surprise to me, especially after cutting up that pig and having the knife increase it's slicing after several cuts through the thick, dirt filled hide on that pig. A pocket DMT hone is easy enough to carry around as well, as I sure can't bring my super fine waterstones and lapping film to the woods with me. I need to get some more rope and start cutting it up (I like thick 5/8" stuff to try to simulate game animals, but 3/4" might be more appropriate) with different finishes to see what works best for me. I will start at DMT Coarse and work my way finer to see what performs best for slicing cuts on rope. Since Phil Wilson has tested so much DMT X Fine will probably end up the optimum finish, as that is what he recommends. Hopefully I will get another chance to skin out a pig to test out a coarser edge for real world performance.

Mike
 
You must log in or register to reply here.
Back
Top