CPM-M4 vs CTS-20CP/CPM-S90V

[Buffalohump]

CPM-M4 is great but it will rust and stain like crazy. I'll take a stainless steel like M390 over that any day. But then I live near the sea... YMMV.

 

[db]

Hi Sal,

Yup, Exactly.

I use as many different steels as I can, it's interesting how similar some of the steels really are in use, say at work.

Jim

I'm guessing that when not testing and really paying attention closely that most steels are pretty darn close to the same thing. I've personally carried and used a few different steels with simular thin and sharp edges just as edc knives and truth is they all needed a sharpening after some good use. I really couldn't tell you nor did I notice if one really out did another. However, I have tested some of these same knives and easily could see a difference but that was all semi controled cutting and paying attention to what I was doing.

 

[lazlo]

I hope Mr.Osbourne doesn't mind me playing on his design...

I think this is how it should have looked coming out of the factory - Cleavers just aren't sexy enough

Ted Ott's blade is wild -- it has a dumbell cross-section.

I'm very curious to put this through some beatings and see what M4 can do
from this...
to this...

Wow, fantastic! Did you grind that cold, or did you anneal it and re heat-treat it? If you ground it cold, that must have taken a long time!

 

[Ankerson]

I'm guessing that when not testing and really paying attention closely that most steels are pretty darn close to the same thing. I've personally carried and used a few different steels with simular thin and sharp edges just as edc knives and truth is they all needed a sharpening after some good use. I really couldn't tell you nor did I notice if one really out did another. However, I have tested some of these same knives and easily could see a difference but that was all semi controled cutting and paying attention to what I was doing.

Yes, I really do pay attention to them and how the differet steels work for different things.

We have to remember that the steels are the teachers and we all are the students and there will always be more to learn.

All I do is gather data for later use and comparisons.

There will be slight differences that could show up in normal use, but not enough to really mention for the most part.

There are a lot of variables that could contribute to those differences also in use.

 

[db]

Oh, I'm always learning from my knives and edges. Somedays I learn I prefer a coarse edge and then there are the other days I learn I prefer a polished edge. Truth is my needs do change depending on what I'm doing and I really notice what type of an edge is needed moreso than any difference between most of the better steel types. I'm kind of a retired steel snob. I've tried many different steels and really haven't been blown away by any of them for very long. Like most here already know you give up one thing to gain in another and for a edc knife what ever is lacking in the steel is going to show up sooner or later.

 

[Ankerson]

Oh, I'm always learning from my knives and edges. Somedays I learn I prefer a coarse edge and then there are the other days I learn I prefer a polished edge. Truth is my needs do change depending on what I'm doing and I really notice what type of an edge is needed moreso than any difference between most of the better steel types. I'm kind of a retired steel snob. I've tried many different steels and really haven't been blown away by any of them for very long. Like most here already know you give up one thing to gain in another and for a edc knife what ever is lacking in the steel is going to show up sooner or later.

Some steels do better with coarser edges than others, usually the higher the carbide content and the finer grained the steels are the better they do for certian tasks.

The level of edge refinement can make a huge difference in edge retention also, and cutting efficiency.

Most of the time from what I have seen in testing and use something in the middle around 6-10 micron finish tends to work the best overall, it gives a nice balance between edge retention and cutting ability. It's refined enough for push cutting while being aggressive enough to take advantage of the carbides as in lower cutting force needed when slicing.

 

[rustyrazor]

Any of you guys that have experience with CPM-M4 and have worked it hard, would you define it as stronger than 5160 as well as tougher? and if so, is there a stainless that compares relatively well? As I'm not willing to use a "super hard" steel for my knives if it can't be resharpened or it's going to break or have the edge chip under hard working conditions.... and I can't believe nobody shat on me for still using 440c I expected at least a laugh or two for sticking with it this long

 

[Ankerson]

Any of you guys that have experience with CPM-M4 and have worked it hard, would you define it as stronger than 5160 as well as tougher? and if so, is there a stainless that compares relatively well? As I'm not willing to use a "super hard" steel for my knives if it can't be resharpened or it's going to break or have the edge chip under hard working conditions.... and I can't believe nobody shat on me for still using 440c I expected at least a laugh or two for sticking with it this long

A lot depends on the hardness really.

There aren't a lot of choices around in M4 in knives that are really hard use as in choppers.... Talking about fixed blades here so we are really talking about customs really for the most part.

There is a big difference in the blade sports guys that can take the blade to a belt grinder and repair the edge quickly and some guy out in the field in the middle of no place.

I wouldn't want to have to deal with repairing an edge on an M4 knife out in the field that was ground thick like a chopper.

I think A8 or 3V would be top choices here, while not stainless they offer toughness and edge retention while still being fairly easy to maintain in the field.

Or you could go with the standard 5160, 52100 and 1095.

The Stainless to look at would be ELMAX.

 

[Ankerson]

HRC hardness can make a huge difference in how tough or strong an edge can be, once we get above 62 HRC with some steels they can be stronger than most people would believe, even more at 64 HRC and above and ground thin.

But again we are geting into Customs here with specialized heat treatments and tempering processes.

Take a steel like CPM 10V and get it to 64 HRC and we have a strong blade that can be ground thin and it will hold up well to hard cutting, but drop that down to 58 HRC ground the same way and it will roll like crazy.

The purpose of the knife really matters a lot when choosing steels and also the HRC hardness will depend on the the knife will be used for.

 

[unit]

I would suggest that M4 properly ground and sharpened will hold up quite well as a chopper and should not require much (if anything) in the way of repair in the field (at least for MY needs). If it does require major repair (belt sander), I would blame myself and not the steel.

Full disclosure, I am not widely experienced with lots of steels on choppers. I have used 1095 and 1075 and M4 (competition grind) rather extensively and I can process the same amount of wood with less edge degradation with M4, and because of the thinner grind that is possible, I can complete my cuts in far less time.

I would also point out that if you attempt to select the "best" steel/hardness/geometry/etc with a blind eye on technique and preferences of the user, you are likely going to have poor results.

Edit to add: any time you REALLY optimize a knife to a user, you will have compromised on some attributes to gain others. You can make a knife that is perhaps indestructible, but it may be so thick as to require far more energy expense to chop through your substrate. Conversely you can make a knife so thin that it cleaves in a single chop, but it also may break if you miss your target. Then there is the elephant sitting in the corner which is maintainability (what good is a knife that you can not maintain when you need to?) Everyone will likely have a different answer, OR good (but not optimized) performance.

 

[robino]

I too am curious of the toughness of say...M390 or ELMAX if they were heat treated to be used for chopping purposes(and if so, would they lose their edge holding qualities)

Wondering if there is a chance for a stainless steel to achieve enough toughness to work as a chopper. Edge retention is their forte, but heat treated as they are now offered in folding knife duty, how do they compare in toughness with M4...? Can one have the maintenance free stainless steel of M390 in the toughness of M4 at some miracle treat that would compliment both, edge retention AND toughness to high enough levels to be used as choppers with great results?

 

[robino]

Ted Ott's blade is wild -- it has a dumbell cross-section.



Wow, fantastic! Did you grind that cold, or did you anneal it and re heat-treat it? If you ground it cold, that must have taken a long time!

Chris from Moss knives cold ground it, he did say it took some time...
But i think it came out perfect. Knife has enough heft to have a decent point and still be thick enough for heavy duty
The grip on the Osbourne was also real thick and needed some slimming down, so that regular mortals without gorilla hands could grasp it.

 

[PeterPHWS]

The difficulty the OP has here is that the best knife makers with skill in using the alternative steels he mentions, such as Phil Wilson, don't do choppers ... and those who do do "choppers" , are working solely with M4 ... such as the Osborne knife he already has ...

The thing with knives at this quality level is that it is all about the "knifemaker" and not the steel ... you would'nt be able to compare the Osborne knife to other steels unless someone like Osborne or Bradley were prepared to change tack and work with those steels to build a similar knife ... meaning that the knife had the benefit of a lot of testing to optomise the HT/HRC and grind for that given steel ...

If you had a good maker give his "best guess" as to putting a knife together in those other steels ... you might be "close" ... but the guys who can do such a job are unlikely to put their name to a knife which they have'nt had the chance to test ...

Personally if I can give an opinion based on having some great blades by those mentioned and a few others by top Smiths from Japan ... you don't really learn a lot about the steel from such great makers ... you learn more about the grind and the HT selection process and basically "their skill" to make a great knife ... the good makers can take an average steel and make a blade which will perform way beyond what you might otherwise expect ... Ankerson noticed this with his Phil Wilson blades when comparing steels ... the results if factored in would simply distort the overall picture when the other knives were factory mass produced blades ...

So if you want chopping knives which can give the Osborne knife a run for it's money in different steels you really need to look at specific custom makers ... and if done to a competition grind ... your own skills ... as competition blades can be warped if your technique is off ...

As others have said ... a lot is down to the "use" which then dictates "the knife" ... missing what you want to hit or catching stones if hitting near the soil ... these factors all change what type of grind works best ...

 

[Ankerson]

The difficulty the OP has here is that the best knife makers with skill in using the alternative steels he mentions, such as Phil Wilson, don't do choppers ... and those who do do "choppers" , are working solely with M4 ... such as the Osborne knife he already has ...

The thing with knives at this quality level is that it is all about the "knifemaker" and not the steel ... you would'nt be able to compare the Osborne knife to other steels unless someone like Osborne or Bradley were prepared to change tack and work with those steels to build a similar knife ... meaning that the knife had the benefit of a lot of testing to optomise the HT/HRC and grind for that given steel ...

If you had a good maker give his "best guess" as to putting a knife together in those other steels ... you might be "close" ... but the guys who can do such a job are unlikely to put their name to a knife which they have'nt had the chance to test ...

Personally if I can give an opinion based on having some great blades by those mentioned and a few others by top Smiths from Japan ... you don't really learn a lot about the steel from such great makers ... you learn more about the grind and the HT selection process and basically "their skill" to make a great knife ... the good makers can take an average steel and make a blade which will perform way beyond what you might otherwise expect ... Ankerson noticed this with his Phil Wilson blades when comparing steels ... the results if factored in would simply distort the overall picture when the other knives were factory mass produced blades ...

So if you want chopping knives which can give the Osborne knife a run for it's money in different steels you really need to look at specific custom makers ... and if done to a competition grind ... your own skills ... as competition blades can be warped if your technique is off ...

As others have said ... a lot is down to the "use" which then dictates "the knife" ... missing what you want to hit or catching stones if hitting near the soil ... these factors all change what type of grind works best ...

As you said I can't even think about Phil's knives when comparing the production blades, the difference is so large percentage wise most people wouldn't believe me if I told them....... And that's with a Normal steel like N690.......

Take the high end steels like M390, S110V, 10V and K294 ect and well we have something to really talk about, they are truly in a class by themselves, even when compared to other customs I have tested. His designs and HT and tempering process are so refined that IMO there is nothing else like them. I HAVE TO compare His knives to each other I have found as nothing else I have seen are in his class or even close to that level of performance. However they do have to be used properly, they aren't ment to be battened, hit with a hammer, pryed with or making twisting cuts through hard materials. Keep the spine of the blade inline with the edge and one won't have a problem.

That said, no we really can't compare Custom knives with production knives MOST of the time.

Production knives have to be much more forgiving and thicker so there are compromises that have to be made for the masses.

 

[rustyrazor]

you guys are amazing... i can hardly keep up to the reading and cross referencing to even get my head around what I want to know. the case with me is close to what most of you are talking about... with the "missing and hitting stones if hitting near the soil" end of it. I don't do competitive cutting and I don't make my knives to be pretty, I just want a steel that gives me the best toughness and strength I can ask (of the steel... the HT, and geometry are my "problem") so to speak. but if I know one steel will hold up better to abuse than all others then that's what I need to use. so far as from what I can gather, the M4 is a pretty good choice if I'm willing to sacrafice a bit of edge holding to the others. much appreciated guys

 

[Ankerson]

you guys are amazing... i can hardly keep up to the reading and cross referencing to even get my head around what I want to know. the case with me is close to what most of you are talking about... with the "missing and hitting stones if hitting near the soil" end of it. I don't do competitive cutting and I don't make my knives to be pretty, I just want a steel that gives me the best toughness and strength I can ask (of the steel... the HT, and geometry are my "problem") so to speak. but if I know one steel will hold up better to abuse than all others then that's what I need to use. so far as from what I can gather, the M4 is a pretty good choice if I'm willing to sacrafice a bit of edge holding to the others. much appreciated guys

Something like 3V would be a very good choice for you or A8.

 

[rustyrazor]

thanks chief... I'm going to take that into the brain box for my next steel order.

 

[PeterPHWS]

Sometimes when working with steels the amount of time and materials needed for some ... 3V being a good example ... has an impact on cost ... Jerry Hossum for instance will work a lot more readily with CPM 154 and S30V than 3V because it is a hard steel to shape a knife with ... check out his thoughts on those steels because he really has put some time and effort into them ...

Some steels are very forgiving such as O1 tool steel ... and in 4 inch blades take an edge and can be worked with right up there with the better steels if you get good at the given properties of that steel ... and it is cheap ... which may make a deal of difference on a business plan ...

The top end steels referred to ... they need the very best of oven controlled temps ... and if making a larger blade ... more expense because of the size of the oven for the blade blank ... and if you make an error in the HT the knife is not as redeemable as steels such as O1 which can effectively give you another "go" at it ... and if making blades for soldiers the price point is fairly critical ... so bare these things in mind ... because you realy will need a bit of time and capital to test the knives you make if you want your name to be "good right from the start" ...

A8 would therefore be my initial thought as it is easier to work ... but if you can spring for 3V and get good at it ... then that would be more attractive to me as a "user" steel ...

 

[robino]

i have seen Koster also using 3V in a lot of his knives as an option, and i see in posted graphs that it is quite the tough steel, but seems to 'lack' at the other end of the spectrum...edge retention.

I would like to see a more evenly matched steel, like the M4, which seems to be a good balance of edge retention and toughness as opposed to other steels which seem to stand out at either end but not at both

 

[rustyrazor]

yeah, I've noticed M4 creeping into a lot of threads as well as A8, then 3v respectively, so it's off to the internet to buy a bit and start the testing process. i'll keep you informed. thanks again