Why does CPM-M4 dominate in national cutting competitions?

It seems to me that these competitors want to win. In any competition that involves some equipment, such as a fast car, competitors want the best they can get. Like the fastest and best handling car, or the best chainsaw or axe or the best rifle and bullet combination. After that, it's skill that helps determine the outcome. So any knife cutting competitor, would of course want what they believe is the best steel for their purpose of winning. They will not pick a steel at random. ZDP-189 is not some unknown steel. It is already a steel used for knife blades. So any competitor wanting to win, who believed that ZDP-189 could help them win, would most likely try it out.
 
ZDP-189 isn't readily available in the U.S., and on the rare occasion that it is, it would be incredibly expensive to use. And yes, it is most likely too brittle to use.
 
Looking at carbide fractions CPM M4 would seem high, but it's only at around 12%. S90V is around 23%. ZDP would be in the same neighborhood.

Typically, higher carbide fractions are more brittle, relatively speaking. They also usually have higher wear resistance.

While excellent steels, I don't think I'd want to try using S90V, or ZDP 189 as competition knives.

Not to be misquoted, I don't think they are particularly brittle when used in small fixed skinners, folders etc. A very fast, high impact competition knife is a different story though.

Note* S30V has a fraction of 14.5%. Not much higher than CPM M4, but would you make a competition knife out of S30V? I sure wouldn't.

IMO, A highly alloyed steel with the fraction of CPM M4 that has the toughness to compete is a rarity. 3V, noted for it's chopping ability has a Carbide fraction of around 5%. That's higher than some of the carbon steels.
 
It is very interesting what the cutting competition sport has brought out as alternative and new steels for that particular use in cutlery. Not that the steels are new perhaps in themselves....just that the blend of heat treatment at a lower level to reduce brittleness has in some measure with CPM M4 introduced a steel with very good edge retention and holding properties which can also absorb some shock impact from chopping.

The grinds on these competition knives and the edge geometry.....is much known about what the competitors are doing here? How acute an angle is the edge taken to? The grind for the most part seems flat to me....but the spine thickness would be of interest in terms of the blade profile.

In so far as the competition rules go....what examination of the edge to determine if there is any rolling or chipping is done? And what can lead to disqualification regarding an unsafe edge?

The fact that mention has been made of "catestrophic" failure on some sites etc and how cracks or dinks in these very highly hardenned steels can quickly spread and cause failure.....does this mean that these knives....to pardon the pun....are right on the cutting edge of what is "useable" and likely to be "long lasting".....meaning that are they like a racing car which can be justified if it wins just a few races....as oppossed to giving a good lifetimes worth of use? In short....are they really unique for competitions where knife makers can make them easily....and are unsuitable for a working knife for the none maker user?
 
I serioucely doubt that competitors in real search for best steel and tryed everything possible. This is not really F1 racing yet. Level of money involved, size of teams - rools is not really established etc... I think no one really do serious researches to find best of the best steel.

As well as ZDP189 brittleness - this is all talks based on partially disclosed composition. I used it for 4 years - it is not brittle, and I have tons of proves. However some people know the truth and do not need to be bothered with facts.

Yes it is not avilable and very expensive (as well as CPM S90V is expensve) - this make it in someone mind "too brittle and hard to sharpen" - which is usual excuses in this situations.

Thanks, Vassili.
 
Mastiff, I think you've given a very fair overall picture. I believe all of us here agree that ZDP is a fine steel, but whether it is suited to the particular circumstances of the tests in the knife competitions is another matter. The contestants are knifemakers themselves -- they know their stuff, and if they favor a particular steel over the others there must be a reason.
 
Vassili, You are exactly correct in saying that I can't say for sure whether S90V, ZDP 189, and others ( cowry X for instance) would or wouldn't make a good competition knife.

I have never tested them, and most likely never will. There are always exceptions as I was attempting to point out with CPM M4.

I do agree, and have gone on record here defending ZDP and S30V, and S90V when people have stated they were brittle.

Being too brittle for a folder or small skinner and a 10" competition knife doing the things done at a meet are completely different though.

Ultimately neither one of us has done it so neither one has any real evidence. Joe
 
if zdp is as tough as S30V/S90V, then it has somewhere around 60% the impact toughness of CPM M4
 
hardheart said:
if zdp is as tough as S30V/S90V, then it has somewhere around 60% the impact toughness of CPM M4
Click to expand...

That sounds about right and if I had to put them in order it would be S30V/ZDP/S90V/.............M4

M4 is a amazing steel but IMO is in a completely different class than any stainless. Carbon steels in general have more toughness, better edge retention, easier to sharpen, and hold a edge longer than the sharpening time would lead you to believe. S90V gets close to the qualities of a carbon steel and so far is the ONLY stainless I would even try to compare to a carbon steel, though I'm sure it would fair well stainless steels are just not on that level yet.

Last week I was touching up my BM 760 on my DMT XX-fine benchstone, I keep the edge on the stone and just move back and forth. I got moving a little to fast for my own good and I slipped off the stone on the back stroke. The main stright edge part of the knife scrapped across the end edge of the stone, my first thought was "this is gonna be bad" and I waited a minute before turning it over. I was expecting something as flat as a butter knife because I hit it with quite a bit of pressure but to my big surprise there was only a very thin, fine line about 2 inches long. I was also surprised that the edge still felt sharp and would shave despite having a visible flat spot. I actually had to look at the edge under light at first to see the damage and even more amazing is the fact it was a lateral load. It sucked because I then had to resharpen it but it proved to me just how tough this steel really is.

Overall, you just can't compare a stainless to a carbon its not fair.
 
About the cutting competitions:

A few years ago the competitions were run by the ABS and the competitiors were required to make thier own knives. Now the events are run by Bladesports International. Competitiors do not have to make their own knives but are required to use knives that have been certitifed by Bladesports. Custom and Factory production knifes are allowed as long as they have passed certification by Bladesports.

Likewise, all competitors must be certified by Bladesports before they can compete. This insures that they have been properly trained.

There is more to this sport than meets the eye and many of the competitiors take it very seriously. They have put a lot of effort into training, technique and developing the best knives for the challenge. It is a unique test of both the knife and the person using it.

The competition courses have multiple cutting challenges. Some required force, some speed, some a light touch and fine edge. There are always some standard cuts such as the 2x4s and hanging ropes but there are also one or two surprise cuts that the competitiors cannot train for. The surprise cuts might be cutting a wet rolled rice mat or slicing the tip off of a flexible drinking straw without bending it.

Many of these cuts are much harder than they look. Cutting a hanging 2" rope is actually very difficult. Speed is also a factor and some of these guys can chop through the 2x4 in a few seconds. The record is under 2 seconds. On some cuts, such as line of water bottles, if you get it right you hardly feel it. If you hit it wrong it's like swinging your knife into a brick wall.

Warren Osborne explained to me how balance and weight distribution are critical elements of the knife design. He said that more competitors have chosen a cleaver type design rather than a Bowie clip point design because it offers more options in weight distribution and knives of different weights can be made from the same design while maintaining the preferred balance. The more weight you have in your hand as compared to weight in the blade, the faster the tip speed. Some power cutters like Gary Bond prefer a heavier knife up to around 1 pound 8 ounces while others like Warren prefer a lighter knife around 1 pound 4 ounces or lighter.

As for the steel, they like M4 because they can make the blade thinner. M4 will take a pretty high degree of hardness without becoming brittle. Most of the M4 competition knives are around 61 Rockwell. Some do use knives made from 01 or other steels. The knives are immediately checked after each round and is disqalified if any damage is found, including any chips or rolling on the edge. Of course failure such as a blade snapping is a major concern as this is a spectator sport and they really don't want pieces flying. Blades have broken it is rare as most competitors have thoroughly tested their knives in training before a competition.

All of the competitors that I have talked to have said that one of the benefits of competing is that they learned a lot about knife steel and knife design. Many are full time knifemakers and they have applied what they learned to their ordinary non-competition knives.

Go to a cutting competition and talk to the cutters. It is a very entertaining and educational experience.
 
Great post ^

Do you know what type of grind is prefered ( convex/flat) and at what level of edge damage is it considered a DQ? I ask the later because its kinda like saying my edge is shaving sharp, there are many different levels.
 
I'm not quite sure I understand the debate, or the desire of some ppl to prove one steel to be the best...

ZDP and CPM S110V, or CPM S125V make great light cutters. As soon as chopping is introduced they won't work that well. I am sure knifemakers can make it work to certain degree, but what's the point taking specialized steel to work so so for unintended use.

Why does it matter if M4 won that competition if I need thin edge and high wear resistance?
I have quite a few knives sharpened to 5-8 deg. per side,64-67HRC, for soft materials including abrasive stuff like cardboard they work exceptionally well and for a very long time. If I try to chop through 2x4 with it, it'll be pretty bad for the edge, no questions asked.

So, do I want those blades replaced with M4? No.
On the other hand I don't want my kukris made out of ZDP-189 or 110V either.

And yes, I do have couple ZDP-189 knives, small folder and 270mm chef's knife. No chipping on either one of them, but I never use any of those for prying, chopping , in the kitchen I always use wood board, etc.

What I want from those knives is thinnest possible edge and staying sharp for a long periods of time on soft materials. And ZDP-189 works very well for that.

Dunno what's the fun if there's just 1 steel to end them all. At least today metallurgy isn't there.
 
Seems like the idea is to find a steel that can do all things pretty well, but not the best in any particular category. Kind of a jack of all trades but master of none steel.
 
knifenut1013 said:
Great post ^

Do you know what type of grind is prefered ( convex/flat) and at what level of edge damage is it considered a DQ? I ask the later because its kinda like saying my edge is shaving sharp, there are many different levels.
Click to expand...

Nearly all that I have seen have been a flat grind. I don't know exactly what level of edge damage is acceptable, if any. I have seen the judges drag the edge across their thumbnail to feel for damage.

I do not compete but I have been to several competions and have gotten to know several of the competitiors. I have covered the championship for Blade Magazine for last couple of years so I learned a lot about the sport from interviewing the competitors and watching the competitions.
 
Mike Carter Custom Knives said:
About the cutting competitions:

A few years ago the competitions were run by the ABS and the competitiors were required to make thier own knives. Now the events are run by Bladesports International. Competitiors do not have to make their own knives but are required to use knives that have been certitifed by Bladesports. Custom and Factory production knifes are allowed as long as they have passed certification by Bladesports.

Likewise, all competitors must be certified by Bladesports before they can compete. This insures that they have been properly trained.

There is more to this sport than meets the eye and many of the competitiors take it very seriously. They have put a lot of effort into training, technique and developing the best knives for the challenge. It is a unique test of both the knife and the person using it.

The competition courses have multiple cutting challenges. Some required force, some speed, some a light touch and fine edge. There are always some standard cuts such as the 2x4s and hanging ropes but there are also one or two surprise cuts that the competitiors cannot train for. The surprise cuts might be cutting a wet rolled rice mat or slicing the tip off of a flexible drinking straw without bending it.

Many of these cuts are much harder than they look. Cutting a hanging 2" rope is actually very difficult. Speed is also a factor and some of these guys can chop through the 2x4 in a few seconds. The record is under 2 seconds. On some cuts, such as line of water bottles, if you get it right you hardly feel it. If you hit it wrong it's like swinging your knife into a brick wall.

Warren Osborne explained to me how balance and weight distribution are critical elements of the knife design. He said that more competitors have chosen a cleaver type design rather than a Bowie clip point design because it offers more options in weight distribution and knives of different weights can be made from the same design while maintaining the preferred balance. The more weight you have in your hand as compared to weight in the blade, the faster the tip speed. Some power cutters like Gary Bond prefer a heavier knife up to around 1 pound 8 ounces while others like Warren prefer a lighter knife around 1 pound 4 ounces or lighter.

As for the steel, they like M4 because they can make the blade thinner. M4 will take a pretty high degree of hardness without becoming brittle. Most of the M4 competition knives are around 61 Rockwell. Some do use knives made from 01 or other steels. The knives are immediately checked after each round and is disqalified if any damage is found, including any chips or rolling on the edge. Of course failure such as a blade snapping is a major concern as this is a spectator sport and they really don't want pieces flying. Blades have broken it is rare as most competitors have thoroughly tested their knives in training before a competition.

All of the competitors that I have talked to have said that one of the benefits of competing is that they learned a lot about knife steel and knife design. Many are full time knifemakers and they have applied what they learned to their ordinary non-competition knives.

Go to a cutting competition and talk to the cutters. It is a very entertaining and educational experience.
Click to expand...

Thanks Mike.
--------------------------------------------------------
Why no Busse / INFI knives in this competition?
Sounds like there is no excuse now.

Maybe it's not all that....
 
Gavin S. said:
Seems like the idea is to find a steel that can do all things pretty well, but not the best in any particular category. Kind of a jack of all trades but master of none steel.
Click to expand...

I think that is the key to a good EDC knife. All steels have some compromise or trade-off. No one steel is going to be best for every application. A EDC might be called upon for almost any kind of utilitarian use so, in my opinion, the more universal the steel the better.

In my opinion, the best all-around steels are 440C or CPM-154. They are not the latest greatest high tech gotta have steels but they are tried and true performers that have served users very well for many years and very tough low maintenance steels that will take a great edge and hold it for a reasonable time.

If you beleive all of the super steel hype you would think that the knives made 50 years ago by people like Bill Moran, Bo Randall, Bob Loveless, Bill Scagel or Gil Hibben wouldn't cut worth a damn but the fact is that they have held up and worked well for countless hunters and soldiers who wouldn't trade them for any other knife.
 
Mike Carter Custom Knives said:
I think that is the key to a good EDC knife. All steels have some compromise or trade-off. No one steel is going to be best for every application. A EDC might be called upon for almost any kind of utilitarian use so, in my opinion, the more universal the steel the better.

In my opinion, the best all-around steels are 440C or CPM-154. They are not the latest greatest high tech gotta have steels but they are tried and true performers that have served users very well for many years and very tough low maintenance steels that will take a great edge and hold it for a reasonable time.

If you beleive all of the super steel hype you would think that the knives made 50 years ago by people like Bill Moran, Bo Randall, Bob Loveless, Bill Scagel or Gil Hibben wouldn't cut worth a damn but the fact is that they have held up and worked well for countless hunters and soldiers who wouldn't trade them for any other knife.
Click to expand...

I did some manil rope edge retention testing and it does show that many hyped-steel are actually not so great, as well as simple good old steel are performs pretty well, but of course you can not generalize and apply it to all steel - final answer is practice and some "super steels" does perform pretty well.

I cut manila 1/2" rope 200 times measuring sharpness at certain steps. This is results:

1. Dozier heat treated D2.
2. Yuna Hard II ZDP-189 (second run)
3. SwampRat SR101 (52100)
4. Spyderco Mule CPM M4
5. KaBar Dozier D2
6. Yukka Hankala hand Forged Silver Steel
7. J.P.Holmes CPM 10V
8. Buck BG42
9. Buck CPM154
10. Yuna Hard II ZDP189
11. Buck CPM S30V
12. Kershaw CPM S110V
13. Fehrman R3V (CPM 3V)
14. G-Sakai SRS15
15. Kershaw CPM S30V
16. Buck 420HC
17. Busse INIFI
18. Benchmade M2
19. Ivan Kirpichev Bulat (wootz)
20. Kiku Matsuda OU31
21. Diamond Knives Friction Forged D2.
22. Kershaw Sandvic 1326
23. Fallkniven 3G (SGPS)
24. RosArms 110x18
25. CRKT AUS8
26. Kershaw SG2
27. Benchmade D2

Results does vary among super steels and average steels as well. But I really doubt that 440C and CM154 is best chose - it is relatively cheap, and more comfortable for knifemaker to work with, but they does performs on average level.

Thanks, Vassili.

P.S. link to results - http://playground.sun.com/~vasya/Manila-Rope-Results.html
 
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