Friction Forged test blade

Wow - thanks for all the work and sharing the results, Phil. Interesting results, and I'd say they all tested out to cut like the dickens. I need to get one of those CPM-154 blades now, too.

And all blades had the same initial cutting force!

Hardheart, that's a nice way to see the results - thanks for the graph.
 
I will be out of contact for about 10 days and will pick this up when I get back. Yes there are some things about this test that were not what you would predict. The FFD2 did cut very well at high force with a blade that had dulled. I think this is due to the very high hardness. 90V did better at mid range --- a bit thinner edge, and 6 pts softer blade. This is the first time I really looked at the specific number of cuts to reach a force level and compared them that way. I will do some more cutting later, in the meantime Wayne and Maynard will will be doing some work that will add to the information pool. PHIL
 
I am just curious. I have tried to follow this from it's inception so forgive me if this was already asked. Is there any benefits to cryo treatment after the friction forge process? I have not read anything that I recall about this so I thought I'd ask.

Other than this thanks Phil. Very good looking results and impressive test.


STR
 
STR said:
I am just curious. I have tried to follow this from it's inception so forgive me if this was already asked. Is there any benefits to cryo treatment after the friction forge process? I have not read anything that I recall about this so I thought I'd ask.STR
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STR,

I have done some preliminary work to determine if Cryo-treatment of FF D2 would produce any additional hardness (martensite). These results indicate no additional martensite formation by Cryo-treatment of FF D2, i.e. no benefit of cryo-treating the FF D2.

TN
 
Wayne G. said:
I cut a bundle of six, one-inch ropes with one of those aweful D2 blades with the massive carbide aggregates.
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Anything will hold an edge for one cut obviously, that is hardly a counterpoint. If you want to see actual functional measurement then see the work done by Landes and counterparts on the various European forums where they focus a lot on push cutting.

Cobalt said:
The last number at 30 lbs makes no sense. for both FFD2 and S90V, almost like if they were reversed. All the other steels went up in number of cuts at 30lbs except S90V? I'd say do over. Also FFD2 is quite high in relation to it's own values. Like it magically sharpenned itself or chipped away and microserrations did the curring.
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THere are always large variations in the way knives blunt, you can even see this in the CATRA results let alone the cutting done by hand. The blades will even get sharper and then fall for the exact reason you noted. If you average about 3-5 runs then you get a fairly monotonic behavior.

-Cliff
 
Cliff Stamp said:
Anything will hold an edge for one cut obviously, that is hardly a counterpoint. If you want to see actual functional measurement then see the work done by Landes and counterparts on the various European forums where they focus a lot on push cutting.


-Cliff
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You missed the point Cliff, you were talking about large blocky carbides in Standard heat treated D2. You made it sound like it wouldn't do much cutting. The standard heat treated D2 blade had cut one, then two, then three, then four, then five and finally six at a time and wasn't dull. I was out at seven so there was no more cutting that day. The out at seven was because the knife turned in my hand, not because the large blocky carbides you keep talking about kept it from finishing the cut. I'm trying to get the point across to you that reality is different than your theory, (on some things).

Wayne G
 
Wayne G. said:
You missed the point Cliff, you were talking about large blocky carbides in Standard heat treated D2. You made it sound like it wouldn't do much cutting.
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No you completely missed the point. It also isn't theory it is measured fact. Because you are unaware of the research does not make it theory, because you refuse to consider it doesn't invalidate it.

The edge stability of D2 is very low because of the large aggregate carbides. What you cited in the above does not examine that as the cited work you referenced tests nothing but INITIAL SHARPNESS. No blade steel is going to be significantly tested for edge retention with just a few cuts on rope.

I made a knife out of MILD STEEL and sliced 3/8" hemp 126 times and it was still cutting very aggressively. Specifically there was only a 18 lbs increase in force from the first to 126 cut.

-Cliff
 
Cliff Stamp said:
No you completely missed the point. It also isn't theory it is measured fact. Because you are unaware of the research does not make it theory, because you refuse to consider it doesn't invalidate it.

The edge stability of D2 is very low because of the large aggregate carbides. What you cited in the above does not examine that as the cited work you referenced tests nothing but INITIAL SHARPNESS. No blade steel is going to be significantly tested for edge retention with just a few cuts on rope.

I made a knife out of MILD STEEL and sliced 3/8" hemp 126 times and it was still cutting very aggressively. Specifically there was only a 18 lbs increase in force from the first to 126 cut.

-Cliff
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Slicing rope with a knife made out of mild steel has nothing to do with neither push cutting nor much to do with edge stability. As it is a measured fact trying to relate it to this is misleading and way off point and confusing the issue even more. Seeing Cliff trying to school Wayne G. on cutting is pretty funny, and beyond silly.
 
Cliff Stamp said:
No you completely missed the point. It also isn't theory it is measured fact. Because you are unaware of the research does not make it theory, because you refuse to consider it doesn't invalidate it.-Cliff
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Cliff,

I thought we had been through this before, but I'll address it again for you. If you are going to sight previous work, please do so professionally and in acceptable bibliographic form. Websites, web forums and bulletin boards do not constitute peer reviewed literature and should be considered opinion.

And please do not reply and quote Landes on this. I find it very hard to believe that you have given Landes a “thorough” review as you say you have given the fact that you (at you own admission) do not read German. I would like to review Landes’ book myself, but I too do not read German.

TN
 
Landes seems to have a typical metallurgical approach - based on testing and observations. I'd like to see some of his test results and see if he has built any empirical relationships between the characteristics mentioned in those posts.
 
Landes post really cleared a lot up for me, and why I don’t notice the carbide stability issue. I rarely go much under 12 degrees per side, 24 degrees, sometimes around 10ish if I really want to spend the time. I also very rarely go up to 8000 grit finish or higher, and prefer a 4000 grit or even coarser finish. I think for those reasons the carbide issue is null for me. It’s probably the same for most as well.
 
Thanks Broos. I will print it off Monday and take a look at it. I still wish I could read German so I could review his entire book.

TN
 
tnelson said:
I find it very hard to believe that you have given Landes a “thorough” review as you say you have given the fact that you (at you own admission) do not read German.
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He reads, writes and speaks english. I have clearified his edge stability testing results in detail through email and in several phone conversations. The numbers in the book where he documents the results of his testing are also clearly in english. I also cited his work in the edge stability article I wrote and sent it to him to confirm that I understood it properly.

The book is also far more than just on edge stability, though that is one of the main focus points. Another is the heat buildup on the edge of a knife using non-water cooled power equipment. He also defines sharpness (two different ways), separates cutting ability, and talks about various aspects of heat treatment. And yes, I have clarified many of these issues with him personally again as well.

-Cliff
 
Maynard and I had a cutting session yesterday. We cut 150 with FFD2 and a Phil Wilson CPM 10V. Pressure was 23-24 lbs with both knives at 150. We’re cutting ten, then making a note of the pressure, then ten more, note the pressure and so on. We will then chart a curve to compare any differences in pressure at a certain amount of cutting. The thin edge was noticeable on the three strand rope. When one strand was on top it would just jump right through with less pressure. The thicker edge on the FFD2 didn’t do that.
We quit at a point where both knives were equally dulled because it wasn’t a fair contest. The FFD2 edge was nearly twice as thick. I’ll get it thinned down enough to match the geometry on the V10 and we’ll cut again. After the 150 cuts the V10 would slice paper a little where the FFD2 wouldn’t but that seemed to be because of the thinner edge. I’ve been developing a sharpening guide that is working out pretty good. We’ll be using it for future tests in order to eliminate any difference in edges.
The 10V was less than .010 in places, the FFD2 was .015-plus, kinda hard to measure because the sharpening land is wider on the thicker blade.

Wayne G
 
I'm doing some testing now with rope cutting (the same Lowe's rope Phil is using) on a D2 blade and a CPM D2 blade. I stopped using and worrying about the scale testing when I noticed in trial runs how much the numbers were jumping around for me and how the thinner D2 blade was cutting with less force even though the edges were pretty much equally sharp as measured on newsprint push cutting and slicing, as well as shaving and how cleanly the rope was being cut. I then went to hanging a weight off of a cotton/poly twine I found at Home Depot and measuring the length of edge to cut the rope to measure the sharpness, as Cliff Stamp describes on his site. I think that test is a much better comparison for blades of much different thicknesses, as the thin edge is obviously going to cut with less force than a much thicker one unless (or even if) it dulls much faster. It makes me think one of my Krein regrinds like the Byrd Meadowlark (.004-.005" edge) might whup up my S30V Manix (.023" or so) using the scale test for slicing rope, even though the S30V's edge would slice better longer, the blade is so much thicker that it would just take a lot more force to make a cut. The twine cutting test also seems better for me as a newbie to rope cutting tests, as my technique isn't nearly as precise or consistent as is required for trying to get accurate results on the scale. I guess I just don't have the experience or skill to get good results with the scale testing yet. My tests certainly aren't the most accurate tests as my human error as well as systematic errors can make my numbers not nearly as concrete as I would like them to be, but I am definately seeing correlation between my sharpness measurements on the twine and my normal sharpness tests like feeling the edge for smoothing and cutting/slicing newsprint, how cleanly the rope is cut, ect. (basically layman's tests that the average guy would do). Hopefully over time I can improve my technique and methods, but in the meanwhile I'll keep enjoying testing and using knives as a fun hobby.

Mike
 
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