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MaxaMet - McCullen

Posted by CliffStamp 
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Re: MaxaMet - McCullen
July 07, 2014 11:48PM
Quote
CliffStamp
The two hardness protocols were not chosen to generate a hardness difference specifically but one maximizes strength and wear resistance and another toughness. The questions of interest then are :

-is the gain in toughness actually of practical benefit

-is the gain in strength/wear resistance of practical benefit

I could not get the exact hardening I wanted as Peter's doesn't do it, but I could get decent ones. I'll discuss this a bit more in detail when I have the knives.
That makes sense. Was Peters not able to do a specific heat treat protocol or just hit the max hardness?

I'll be interested in hearing Jeremy's, and your commentary on the difference (if any, or perceivable) amount of grindability between the two.

wouldn't mind trying to tackle this beast some day.



Edited 1 time(s). Last edit at 07/08/2014 12:17AM by StanLee.
Re: MaxaMet - McCullen
July 08, 2014 01:22AM
I wanted :

> a) austenize at 2225 F, oil quench, temper at 1000 F, cryo, two more tempers at 1000 F

> b) austenize at 1950F, oil quench, three 2 hour tempers at 1025

They can not do oil and they can not reach the upper temperature so I ended up with :


a) austenize at 2150 F, nitrogen quench, temper at 1000 F, cryo, two more tempers at 1000 F


b) austenize at 1950F, nitrogen quench, three 2 hour tempers at 1025.

The max hardness/wear resistance comes from a, b maximizes toughness .
Re: MaxaMet - McCullen
July 08, 2014 01:46AM
Cliff, could you not have used your 'winsome personality' to get Kevin Cashen to ht those to your specific requirements? winking smiley
Re: MaxaMet - McCullen
August 05, 2016 05:50PM
With the release of the Spyderco Maxamet Mule, I was interested after looking at the composition of the steel. How did the Maxamet knife compare to the other high-carbide steels?

Edit:
Compare in use that is.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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Edited 1 time(s). Last edit at 08/05/2016 05:51PM by jasonstone20.
Re: MaxaMet - McCullen
August 05, 2016 06:29PM
I was just thinking about this as Ankerson released his testing on it.

[www.bladeforums.com]

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_______________________________________________________________________________________________

Always in search of a good choppa'
Re: MaxaMet - McCullen
August 05, 2016 08:00PM
I have a Mule in Maxamet, I will be sending it out with a 52100 Mule as soon as Canada posts stops spazzing about. I will put up a sign up thread shortly.
Re: MaxaMet - McCullen
August 06, 2016 11:31AM
I'm tempted to get one of the Maxamet mules from Spyderco. They're not as expensive as I thought they might be.

I don't know that I'd get much use out of it though. I had the K390, but sold it after very little use. It had a heavy edge bevel and didn't do much for me in terms of cutting ability. Decided it wasn't worth it to me to mess with the geometry.

Also have the B70P mule, which has been great; thin edge, sharpens easily for me, stainless. In terms of what I'm likely to use, it would probably make more sense for me to buy another one of these or maybe the RWL-34.

A 52100/Maxamet pass around sounds good though.

-Nate
Re: MaxaMet - McCullen
August 06, 2016 03:37PM
I know I could probably find this somewhere else, but what do you guys think about the handle on the Spyderco Mules? They look decent but possibly small for my hand, a few of Sal's designs are like that for me.

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Re: MaxaMet - McCullen
August 06, 2016 07:53PM
If you've ever held one, it's similar to the shape of the Stretch behind the choil. I like it quite a bit. I have average sized hands though, so most grips are fine for me. To some extent it would depend on what you do for scales too I guess.

-Nate
Re: MaxaMet - McCullen
August 06, 2016 09:16PM
Is it the same approximate size of the stretch handle? I had a stretch II in ZDP-189 but I traded it because the handle was just too cramped for me. The shape and contouring of the handle was perfectly fine, I just have pretty big hands, an XL glove usually. I really loved the blade shape though. The mules seem interesting. I haven't seen or held one but if it's a decent and relatively cheap way to sample different steels, is probably be able to get over the handle.
Re: MaxaMet - McCullen
August 06, 2016 09:33PM
Pretty much the exact same shape/size:

[www.spyderco.com]

-Nate
Re: MaxaMet - McCullen
August 06, 2016 10:58PM
Thanks for the link Nate, that's exactly what I was looking for.
Re: MaxaMet - McCullen
September 01, 2016 09:46PM
Cliff,

Have you tested Maxamet to the point that you can make a conclusion? I read Jim Ankerson's testing and it seems that its performance on the Spyderco Mule team is one of the highest ever? Is this steel so superior in edge retention to steels like S30V?
Re: MaxaMet - McCullen
September 01, 2016 11:27PM
Quote
Caraldc
Cliff,

Have you tested Maxamet to the point that you can make a conclusion? I read Jim Ankerson's testing and it seems that its performance on the Spyderco Mule team is one of the highest ever? Is this steel so superior in edge retention to steels like S30V?

Caraldc... you have read Cliff's conclusions on Ankerson's testing, haven't you? Ankerson's method of testing is flawed, and he has ignored this. Why bother with his steel chart?


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Re: MaxaMet - McCullen
September 01, 2016 11:31PM
Quote
Chum
Caraldc... you have read Cliff's conclusions on Ankerson's testing, haven't you? Ankerson's method of testing is flawed, and he has ignored this. Why bother with his steel chart?

Yes I have Chum. This is precisely the reason why I'm asking Cliff about his testing and results.I haven't found any other performance reviews yet.
Re: MaxaMet - McCullen
September 02, 2016 02:33AM
Quote
Caraldc

[...]

Is this steel so superior in edge retention to steels like S30V?

In short, anyone talking about one steel being better than edge retention over another doesn't understand very much about edge retention. Edge retention is going to depend on what is being cut, how much is cut, the angle/grit and general conditions. It is a mix of :

-wear resistance
-impact toughness
-strength
-corrosion resistance

Now if you had a steel which improved all of those properties over another then maybe you could say it had improved edge retention, but that is rarely the case. S30V is far more wear resistant than AEB-L, but it doesn't have improved impact toughness or strength or corrosion resistance. In fact it has lower strength/toughness on a very small scale (~micron). Thus which steel has better edge retention depends on what is being cut and how.

Maxamet has a very high wear resistance, it has a very high strength (on a large scale), it has very low strength on a small scale (~micron), it has low toughness overall, low corrosion resistance.

I have looked at Maxamet and other very high carbide steels, I generally don't find they excel at typical low stress slicing (rope/cardboard). I constantly see performance increase for awhile with carbide content, it then hits a plateau and then decreases. I have talked about why I think this is the case before, I think it is an issue with very low apex stability of those steels.

Just to clarify, I don't think Jim's methods are invalid, I would say that what he does can't support the claims he makes. I have wrote here in some detail why those methods can't do that. To clarify I said all this YEARS before Jim started talking about his work, the same reasons are why I stopped doing cutting like that as I started doing similar work, you can see it in the early reviews. I stopped once I understood :

-blunting is nonlinear
-at some point the rate of sharpness loss becomes extremely low
-when you are in that region it takes a LOT of material to make even small changes in sharpness

The result of that is that precision is very low when you are in the tails. To put this in perspective, I have cut up to a MILE of cardboard with a basic knife and when you are at that point there is almost no change at all in sharpness from cut to cut, or even from hundreds of cut to hundreds of cuts.

There is more detail on the math in other posts.
Re: MaxaMet - McCullen
September 02, 2016 02:47PM
Thanks Cliff. I should've been more clear on the edge retention question as I do understand that it depends on many factors. I should've been specific and said that I was refering to slicing edge retention on abrasive materials such as cardboard and rope. I guess you did answer my question when you mentioned that "I have looked at Maxamet and other very high carbide steels, I generally don't find they excel at typical low stress slicing (rope/cardboard)".

Perhaps I can infer that Maxamet would only have a slight advantage over steels such as S30V when cutting abrasive materials.
Re: MaxaMet - McCullen
September 02, 2016 09:14PM
To be specific, here is an example of what I am talking about :

-harsh cardboard : [www.cliffstamp.com]

and in more detail on regular cardboard :

[www.cliffstamp.com]

In general, I severely doubt anyone can by hand make a more precise separation than the three classes that I noted. I was kind of surprised that it turned out so coarse, but no matter how many tries I tried, I could not get any consistent category which was more precise.

-type I : low softness, low carbide volume
-type-II : moderate hardness, moderate carbide volume
-type-III -high hardness, high carbide volume

I actually expected that there would be a type IV, but they just don't turn out to be significantly better than the type III and often can be worse. I still hold out they might be, for example a cold work high-tungsten steel, ~70 HRC .Unfortunately these are rare because in industry you need the high hot hardness, but for cold work in fine edge holding, they seem to be worse for me.

121REX for example I can't get to perform well for edge retention no matter what I try and I have gone high/low on both grit and angle.
Re: MaxaMet - McCullen
September 02, 2016 09:59PM
Quote
CliffStamp
I actually expected that there would be a type IV, but they just don't turn out to be significantly better than the type III and often can be worse.

I always wondered why there wasn't a class IV in your charts because steels such as 10V, etc. are a lot more wear resistant than steels such as S30V and Elmax. Now it's clear why; in this case the additional wear resistance is of little benefit for long lasting edge retention in hand held knives. This is very interesting!
Re: MaxaMet - McCullen
September 03, 2016 11:18AM
Cliff, where does something 'high hardness, low carbide' like 1095 at 65 or M2 or even AEBL at 62 fall in the three types?

_______________________________________________________________________________________________

Always in search of a good choppa'
Re: MaxaMet - McCullen
September 03, 2016 07:36PM
Quote
C Amber
Cliff, where does something 'high hardness, low carbide' like 1095 at 65 or M2 or even AEBL at 62 fall in the three types?

To be clear, the categories over lap at the edges, the performance is a continuous spectrum.

1095, well hardened at a high hardness tends to be upper of class II or low class II. It is outperformed only generally readily by a very similar steel which is just slightly higher in carbide volume, M2 for example hardened as a cutting tool (industry). AEB-L with a similar hardness is mid to high class II. It should be possible to get AEB-L up to ~65 HRC, but I have never seen it but it looks like it on the data sheets.

At some point I intend to take a hard look at 121REX again and see if there is some way to get it to hold a high sharpness for a long time.
Re: MaxaMet - McCullen
September 03, 2016 09:29PM
Thank you Cliff.

_______________________________________________________________________________________________

Always in search of a good choppa'
Re: MaxaMet - McCullen
September 05, 2016 08:41PM
Cliff,

Would you be able to give me a sense of how low the apex stability of Maxamet would be expected to be, ideally by comparison to other commonly used knife steels?

I'm trying to get a sense of how much apex stability is being traded away for the massive wear resistance.
Re: MaxaMet - McCullen
September 06, 2016 12:38AM
I am not sure what you mean exactly?
me2
Re: MaxaMet - McCullen
September 06, 2016 01:05AM
Cliff, when cutting the mile of cardboard with the cheap knives, did you find it necessary to clean off the edge periodically? I found this to be necessary when doing the cheap kitchen knife up to 3000 feet. The gunk stopped the cutting pretty quickly. Cleaning it returned it to what I expected. I checked a Cold Steel Lite Hunter up to about 1500', but had to clean the edge after every 100 to 200 feet. I intend to take it to a full mile, but I ran out of cardboard, and have been using it in the kitchen.
Re: MaxaMet - McCullen
September 06, 2016 03:08AM
Quote
CliffStamp
I am not sure what you mean exactly?

I am trying to understand how relatively high or low the apex stability of maxamet is, as it would be heat treated by Spyderco, since Spyderco is starting to develop models using maxamet.

I was suggesting that it would help me contextualize how high or low the apex stability of maxamet was if you could compare it to a few other commonly used blade steels, such as those used by Spyderco including VG-10, 8cr13mov, s30v, s110v, etc.

I suggested this because I think I have some sort of mental map of the relative apex stability of some of these commonly used steels, and thus if you were to tell me that the apex stability of maxamet would be expected to be higher than steel X but lower than steel Y, it would help me mentally categorize how high or low the apex stability of maxamet with a sensible heat treat would be expected to be relative to those steels I am already familiar with.

I believe that having a better sense of the relative apex stability of maxamet would help me decide whether I would potentially be interested in acquiring a knife using maxamet at some point in the future.

Does that help clarify my meaning?
sal
Re: MaxaMet - McCullen
September 06, 2016 03:09PM
Hi Cliff,

Maximet has been an interesting study so far. Thanx for the suggestion. The Mule Teams were made in Taiwan and heat treated there. The Manix model was made in Golden and heat treated by our local guy. He's a metallurgist graduate of the School of Mines so his academics are good for what he does for us.

We're hoping to get more testing out in the real world. One of the testers just retested at 18 DPS and got better results than his original test at 15 DPS, which does support the theories.

We learned early on with CPM440V (S60V) that a softer steel (55-56) performed much batter than the original hardness (59-60). This was in the med 90's.

The steel cost is 3X "normal" powdered steels like S30V and processing has pulled cusswords from both our Taiwan maker and our Golden facctory manager.

sal
Re: MaxaMet - McCullen
September 06, 2016 04:18PM
Sal,
Michael Christy just did a YouTube of his testing and sharpening the Maxamet Mule, comparing it to the Farid in 10V:
[youtu.be]

He seems to be impressed with it.

"I am still discussing issues of steels and performance at this stage." -- Cliff Stamp, May his memory be a blessing
"Life is GOOD", -- Stefan_Wolf, May His Memory Be A Blessing
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sal
Re: MaxaMet - McCullen
September 06, 2016 04:34PM
Thanx Jason, great link.

sal
Re: MaxaMet - McCullen
September 07, 2016 09:17PM
Quote
sal
processing has pulled cusswords from both our Taiwan maker and our Golden facctory manager.

sal

So it seems that Maxamet is more wear resistant than CPM S110V. If this is the case, I’m trying to understand why; it has less carbon, less vanadium and no niobium. But, it has 13% tungsten. Is the additional wear resistance coming from a large number of tungsten carbides? Another reason could be that Maxamet is harder? Why can Maxamet reach a higher hardness?