Friction Forged test blade

Phil,

Thanks for sharing these results.

The difference in thickness at the edge may be slowing down the FFD2. Our early tests would give a 20% increase in the number of cuts going from a not real thin flat ground to thinner hollow ground on the same blade.

Maynard is off to Alaska on Monday so we won’t get to test the CPM knives you are sending until he returns. I will be sure to thin the FFD2 blades so that they match the CPM blades.

Maynard was thinking that it might better to use 5/8” rope in order to speed up the testing. He pretty much wrote it off today so we’ll be sticking with the ½”, hopefully without the plastic tracer in it. I’ve got some fuzzy rope here that I got from Ray Richard. I will try to get time to get some tests done with it before Maynard returns.

Wayne G
 
Phil Wilson said:
The FF blade is RC 65+ and the CPM D-2 blade is 62.
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Regular D2 can get 63/64 so CPM D2 should be able to pretty much match the hardness of the Friction Forged blade. This would significantly reduce the performance gap.

I lay the blade on the skin and slide into the hair with out cutting the skin.
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Is there any draw or slice?

-Cliff
 
Put a thin polished edge on a knife, push it straight down through the rope and just keep going till you get tired and don't pay any attention to the pressure required.

It's got to be same day, same cross section, same sharpening and same rope... cut until the same degree of dullness at a predetermined point. This is the closest we can come to fair testing.

Wayne G
 
Wayne, Busse has done more cuts than that live and the blade still shaved so they are hardly ignoring the force required as the only thing which influences the increase in force during the cutting is the loss of sharpness. THey also do it with the same edge geometry which chops the concrete block.

-Cliff
 
I'm aware of all such results but there is one element I see missing.

What same day, same rope tests have they done with other steel types?

I'll have to dig a bit but there is one claim of (I think) 10,000 cuts if I am remembering right.

Some folks seem to miss the object of comparing blades with different steel types, heat treat and cross section geometry. Let's say I weld up a billet of magic steel types, do mystical heat treatments on the blade and then advertise a fantastic number of cuts. No comparisons done, just the big number advertised of the one time test. Has anyone learned anything from that?


Wayne G
 
cds4byu said:
I'll post what I can. What specs do you have in mind?

Carl
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Thanks, Carl. Just wanted blade specs; I've heard more than enough for now about the "nano-technology".:)
Just the basics...blade lengths, widths, and thicknesses of the models soon (very soon?) to be available for purchase. And, if any, or all of them, will be available with full tangs.
I'm a fan of Knives of Alaska; have three models currently, and they all serve me very well. I'm looking forward to getting one of these FFD2 bladed models, as long as they have full tangs.
 
Cliff, Yes a harder CPM D2 blade would be more competitive but I don't think it would be a practical knife for real use. As I mentioned before it gets chippy with this thin edge over 62. At this pt I only have one blade to work with. Both knives were optimized for the intended use so even though it is not apples and apples I think the information is usefull.

the hair cutting is just a push motion against the base of hair in contact with the skin. Phil
 
Wayne, yes I think the thinner edge has an advantage but both of these knives are in the area of what I would call thin. .015 is pretty thin for a general use hunting knife. If you do thin it out then I would like to do the same wood cutting toughness test as I described. IMHO the edge section on the FFD2 knife as I recieved it seems balanced with the extreme high hardness. Interesting stuff! PHIL
 
A few more thoughts:

Based on this one test there is some pretty good information that can be gleaned:

The FFD2 blade is very good. As advertised the small grain size enables a very high hardness with still reasonable toughness for a working blade. The design, balance and feel of the knife are perfect.

CPM D2 is a new steel and not much is known about it. In fact this is a first melt and further production may not be available. There is no data sheet so the blade tested was my best first effort at heat treating. It measured up pretty well against a steel with a finer grain and a much higher hardness.
Both knives cut pretty much equal up to around 100 cuts. In the real world working on game in the field that is more than enough to field dress, skin, quarter and bone out a large animal like an elk. At that point you would probably want to sharpen both blades if you are even a little bit fussy about sharp. This is important since my self and other knife makers will probably not have access to the FF process.

The FFD2 is easy to sharpen if you have the right stones and are experienced with getting an edge on very hard steel. The CPM D2 with a thin edge IMHO is easier to sharpen. In fact I was able to get a working edge back on it by just stropping it on loaded leather. I had to go back to the stone for the FFD2. This is a matter of degree and as the FFD2 blades get into service there will be more feedback here.

Phil
 
Phil Wilson said:
Cliff, Yes a harder CPM D2 blade would be more competitive but I don't think it would be a practical knife for real use.
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It depends on the amount of toughness the user requires. I have blades that are about 0.015" at 1/4" thick back from the edge up in the primary grind and are 66 HRC. I cut with them fine, don't twist on the knife of course.

My point is that for edge retention you are seeing a large HRC influence there which can be eliminated. Now if you then want to argue the friction forged blade would be tougher that would be a valid point due to the smaller aus-grain and finer carbide distribution.

But note here that all that is being argued to be offered in that case would be additonal toughness for less than ideal cutting methods, not additional sharpness nor edge retention.

Wayne G. said:
Has anyone learned anything from that?
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Yes that the knife can do as described. Obviously that is useful information, but limited. Now there is a valid question of course which is "Is that high, medium or low performance?" Simply, what other knives could match or exceed that? Since he has had an open challenge unanswered for many years it would seem obvious the answer.

My main point was that your description of the test was completely inaccurate. They use the standard edge which also does wood and concrete chopping and they cut a large amount of rope and the knife still shaves so it isn't keep cutting with a dull knife to get a huge number.

-Cliff
 
what is the challenge specifically? Anyone with the rope and time should be able to do this with knives from their collection. (I guess I just need the rope) I can understand manufacturers not wanting to advertise results if they don't reach a higher number. Even if the knife is cheaper or more readily available, a high number that still doesn't exceed the ones by Busse would be viewed as relatively poor performance by some. Marketing can be funny.
 
To match/exceed the performance of the knives. He has restated it on the forum on multiple occasions.

-Cliff
 
It is also worth noting, with Busse's live rope cutting tests, that Busse marked off a small (1 inch, if I'm remembering, correctly) section of the blade, and did all 2,771 rope cuts with that same small section of the blade, not the entire blade edge.
 
I had a 14 inch length of the rope left, not really enough to compare two knives, but decided to cut with the CPM S90V Silver Peak Hunter that I have in my own kit. I ran out of rope at 175 cuts and 26-27 lbs on the scale. It does have a smooth spot on the belly at this point, pretty much like the other two knives. This blade is thin, 0.10 at the main edge and tapers to 0.008 at the upsweep to the point. Hardness is RC 60. On the basis of this one test I can say that it was noticeably better than the CPM D2 and would be in the same ball park with the FFD2 with its existing geometry. I will get some more rope tomorrow and will do a side by side with this knife and the FFD2. I have a CPM 154 blade at RC 62 that is a great cutter and also want to compare that one. In the near future I will have the CPM 10V blade done and also have a ZDP 189 knife I can run as soon as I get a handle on it.

Cliff, You are right hardness looks like the governing factor here. I could make a RC 64 blade out of A2 or even 66 with CPM 10V. They would be tough enough to cut rope ok if there was no twisting but they would not be knives that would stand up to use in the field. The Goddard design KOA knife I have is a hunting knife and the knives (mine) I have been comparing them to are also designed for hunter utility use. It seems to me the KOA FFD2 has been optimized to the correct edge geometry for the hardness and it seems tough enough to do the job. Otherwise at this hardness (67 or so) these guys are going to get a lot of knives back with chips and edge breaks. I go to lengths to explain the limitations of the hard thin knives I make so I can afford to err on the side of hard and thin. I know I am not comparing apples and apples here, said it from the beginning but I hope the information will be useful for comparing several hunting type knives. Phil
 
Phil, after you get some more rope is it possible to add a more common blade to the test? Maybe some type of factory knife like a SAK or Mora or something.
 
db. Yes I could do a few tests like that. I don't have any factory knives except some folders. In general the blade length is too short for a fair comparison on those. In addition I am open to a visit to my shop for someone in the area who wants to bring a lot of rope, a few knives and spend a day. On the other hand this testing takes a lot of time and when I am testing I am not working on knives so there has to be a reasonable limit on what I can do. Have you taken a look at what Cliff has done on some of these knives you mentioned? His testing is a lot more precise than what I am doing and there is a whole lot of information there... Phil
 
Phil Wilson said:
db. Yes I could do a few tests like that. I don't have any factory knives except some folders. In general the blade length is too short for a fair comparison on those
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Good point. I had just thought a more common factory knife would probably show a larger difference from all the harder knives.
. In addition I am open to a visit to my shop for someone in the area who wants to bring a lot of rope, a few knives and spend a day. On the other hand this testing takes a lot of time and when I am testing I am not working
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I'd love to stop by and do just that. If I find myself in Northern Cal, I'll look you up.
Have you taken a look at what Cliff has done on some of these knives you mentioned? His testing is a lot more precise than what I am doing and there is a whole lot of information there... Phil
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Yeah I've seen alot of Cliffs stuff. I was thinking more that they would be a good way for us on the forums to relate to your cutting test. Even without you are provideing some very good and interesting info, thanks alot. I think I'm going to have to pick up some rope and do a little playing soon. :)
 
Phil, if I had any money I'd almost rather pay you to test blades than pay for a knife. Well, now it sounds like I don't like your knives or something. I love seeing testing!
 
Larrin said:
Phil, if I had any money I'd almost rather pay you to test blades than pay for a knife. Well, now it sounds like I don't like your knives or something. I love seeing testing!
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Yes sir - Thanks for doing this and sharing your results, Phil.
 
Phil Wilson said:
I could make a RC 64 blade out of A2 or even 66 with CPM 10V. They would be tough enough to cut rope ok if there was no twisting but they would not be knives that would stand up to use in the field.
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Phil what problems are you seeing here, I know lots of guys who run very thin blades on 1095/M2 at full hard for such work with no issues.

-Cliff
 
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