Pick the next mule steel!!!!!

[PocketZen]

I'd like to see some of the newer CTS steels. For sure B75( BG42), B70 (CRB 7), 40C ( 440C). These are all clean, powder steel versions of these steels. These come from the stainless bearing steel category. The CTS steels we've tried so far have been pretty impressive. I'm especially looking forward to the powder steel version of one of my old favorite stainless steels, BG42.

3V will be coming out in the Tuff. I'd like to try Vandis 4.

PD-1 or Z wear which are powder steel versions of Cruware/vascowear.

CTS-B70 gets my vote tied with Z-Wear

[The Mastiff]

Nice choices Zen. Those are steels I'd like to try myself. I know Strider has done some SMF's in PD1, so the steel must be fairly available. Z wear I'm not sure how easy it would be yet. It looks great on paper though.

CRB 7 I've never tried and want to. The CTS steels have been very nice IMO. Clean, good performing. I like the CTS version of S30V better than the original by first impressions. It takes nice edges.

Joe

[The Mastiff]

I just thought another classic might benefit the Mule team program. A2 steel is a very nice steel for field and camp type knives. Good toughness and pretty good wear. Not bad corrosion resistance for a non stainless either. A great all around type. It shouldn't break the budget for a lot of us either.

[Ankerson]

I would like to see steels that we haven't seen in production blades of any kind, steels that we normally see only in Custom knives for various reasons.

I think that was, is the purpose of the Mule Team in the 1st place and with Sal being a steel junky that would make a lot of since. That and a test bed for getting new steels out into the field at reasonable cost.

With the Mule team the numbers can be held to a min as in knives made and certian steels being very expensive, not avaiable in large quantities and hard to work with that keeps the cost down some what.

[Mallus]

I second AEB-L at high hardness. The idea of a humble but smart choise of elements is intriguing. I'm intrerested in high initial sharpness / edge stability and would like to test how well the famed small carbides accomplish this. Also, managing on a shoestring budget, it would be nice to have some affordable steels to test for a change - AEB-L would be easy in that regard.

[JacksonKnives]

13C26 is an alternative to AEB-L, if Sandivik is easier to get steel from. I believe Sal has been hesitant to use this steel in the past because it's a "lower carbon" steel. Hopefully that doesn't exclude it from MT consideration... [edit: can't find reference, could be thinking about a different steel.]

I agree with Ankerson about new/obscure steels, but I think that the *other* benefit of the MT project is that we get to see what Spyderco's heat treat experts can do with steels other makers have chosen not to get full performance out of. (E.g. M390...)

(Devin Thomas has a good writeup about AEB-L here.)

[Mallus]

Yup, the good experience the Thomas Dynasty has had with AEB-L / 13C26 is what grabbed my interest in the first place. The composition of the steel is decidedly unsexy at first glance, but maybe the beauty would just be buried deeper?

Now that Spyderco seems to have decided that the kitchen knives to come should not break the bank, I'd consider AEB-L a good candidate for that application being (believing the hype) affordable, easy to sharpen and able to take a sharp edge. Also for kitchen the ultimate abrasion resistance is not that important, if the other qualities are there. I'd sure like to buy a Chinese cleaver made out AEB-L but cannot afford the custom creations. Why not start with the mule to build up some more experience?

[toomzz]

Maybe we should give the Japanese OU 31 a try.

[razorsharp]

Maybe we should give the Japanese OU 31 a try.

extremely old quote from sal "We tested some about 10 years ago. As I remember, the special ingredient they were using was the addtion of copper. Our tests were OK. We were also testing and using ATS-55 (Custom made by Hitachi for Spyderco) and VG-10 at the time. Our main Seki maker said that he thought that the OU-31 material was more brittle than he liked for a production steel. Maybe we can play with some if the "Mule Team" project works out.

sal"

also see its either like m2 or d2, so sounds good to me.

and i read micro fine.....if it can get extremely sharp, im in

EDIT: found this quote. "OU-31 steel It is a micro fine steel made by Nippon Koshuha Steel Co., Ltd. It features high hardness, HRc 64, and is 3 times tougher than that of D2. Reported to have 10 times longer edge holding than ATS-34 according to cutting tests."

sounds almost too good to be true :D

[Cliff Stamp]

13C26 is an alternative to AEB-L, if Sandivik is easier to get steel from. I believe Sal has been hesitant to use this steel in the past because it's a "lower carbon" steel. Hopefully that doesn't exclude it from MT consideration.

AEB-L has more carbon in the steel than almost all of the other choices in this thread. AEB-L can reach 65 HRC after tempering and has a wear resistance exceeding 52100. However unless you are running it at that hardness with a proper heat treatment for removing retained austenite and secondary carbide precipitation, you would be much better off with 12C27M if the goal was a low carbide stainless at 59/60 HRC.

[Rockcrawler]

I would really love to see any one of the Bohlers tool steel for knives mentioned above, Shirogami, or some other high carbon / non-stainless steel!

Elmax sounds pretty sweet too. Sounds like a great variation in results at different RC, I wonder what hardness the mule will be offered in?

[hunterseeker5]

Ok after some poking around various steel charts in a characteristically shallow way I've come up with a few steels. CPM 15V contains a whopping 3.4% carbon, and so does CPM REX 121, both contain little chromium 5.25 and 4% respectively, and massive amounts of other alloying elements. REX contains only about 9% vanadium, but has that much or more of both cobalt and tungsten. Oh yeah and there is a healthy dose (5%) of molybdenum in there too. 15V contains almost 15% vanadium and not much of anything else, but a few little bits. Bottom line is that both sound pretty amazing. Mastiff mentioned REX 121 already, but not 15V. Thoughts? Oh and its worth mentioning the almost mythical 125V is a mere 3.25% carbon 12% vanadium and 14% chromium along with little bits of a few other things. It sounds almost lame by comparison, just a kiddie little amateur steel. :P

[JacksonKnives]

AEB-L has more carbon in the steel than almost all of the other choices in this thread. AEB-L can reach 65 HRC after tempering and has a wear resistance exceeding 52100. However unless you are running it at that hardness with a proper heat treatment for removing retained austenite and secondary carbide precipitation, you would be much better off with 12C27M if the goal was a low carbide stainless at 59/60 HRC.

You're right, Cliff, Now that I think about it I'm pretty sure it was actually the lower corrosion resistance that Sal said gave him pause for EDC models. (Not that it's all that bad... maybe I'm remembering a discussion about a totally different steel...)

Either way, I can't seem to find the thread, and what I did find says he's considered these types of steel for the MT. Which is great!

[The Mastiff]

There's nothing lame at all about S125V. I've found I'm not really going to get my best edges out of the super high carbide steels. I have two knives in S125V. One in S110V. I'm having a custom made in 15V which I am providing the steel for. It's mostly for testing like Jim Ankerson does and I don't expect to carry a 15V knife as EDC. The S110V Phil Wilson, yes. That I would. It's a monster too.

Anyway I was pretty convinced that Rex 121 wouldn't be a great steel for knives. If it is made into a knife it should only be worked on by a custom maker not making it in huge batches.

My favorite steels so far in the mule team are the 52100, CPM M4, and Super Blue. The Cobalt Special is pretty cool too. I have high hope for the cruware.

I guess if I have to choose, I'll take super sharp edges over very high wear resistance. I don't mind sharpening and I don't mind de rusting steel.

Joe

[JacksonKnives]

Come to think of it, when I've been thinking about high-stability steel, I've completely forgotten about the humble MT5 in 9Cr18Mo. Anyone remember what the hardness was on those? I know my Resilience loves to be sharpened, though I've been using more as a beater and less as a razor. Any of the Byrds known for especially high-RC HT?

[Zenith]

I would like to see steels that we haven't seen in production blades of any kind, steels that we normally see only in Custom knives for various reasons.

I think that was, is the purpose of the Mule Team in the 1st place and with Sal being a steel junky that would make a lot of since. That and a test bed for getting new steels out into the field at reasonable cost.

With the Mule team the numbers can be held to a min as in knives made and certian steels being very expensive, not avaiable in large quantities and hard to work with that keeps the cost down some what.

This is why I want to see Nitrobe 77.



This is what Des Horn had to say, that is to my knowledge the only maker using it to date.

As can be seen from the chart posted NITROBE 77 has almost no Carbon (0.1%) which has been replaced with Nitrogen at 0.9%.
Being the local sole agent for Damasteel I received an experimental batch and have been using it for the last year .
It is absolutely stainless and can be put in a dishwasher!
It is tougher than RWL 34 at a hardness of 62HRC .
Its most impressive feature is its super sharpness. As a result of the size of the molecules it has a much finer edge geometry than RWL34 making it sharper.

It machines, grinds and polishes fantastically but it does have drawbacks for the maker.
There is de-nitrogenisation of the surface during heat treating.
Still in the experimental stage we do not know exactly how deep this is so I am heat treating at full thickness and grinding hard.
The heat treating is complex with four (yes 4) cryogenic quenches in liquid nitrogen between hardening at 1100°C and three 1 hour tempering cycles at 480°C .
Nitrobe 77 shows more potential as the ultimate knife steel than anything I have worked with to date.
There are a number of excellent blade steels available but Nitrobe 77 is harder sharper and tougher than anything I have ever used.

[Cliff Stamp]

Anyway I was pretty convinced that Rex 121 wouldn't be a great steel for knives.

Depends on what you want, it would be horrible in many respects as it has extremely low toughness, grindability and edge stability. But it has extremely high compression resistance and wear resistance. The low grindability is going to influence cost of manufacturing as you are looking at a many to one time compared to something like D2.

You're right, Cliff, Now that I think about it I'm pretty sure it was actually the lower corrosion resistance that Sal said gave him pause for EDC models.

That is the heat treatment, it needs a very high austenization temperature to ensure that the chromium goes into solution as it does not have the excess that steels like 440C have which will put the same amount into solution at a much lower temperature. But there are many other reasons why you want a high austenization temperature with AEB-L anyway such as minimal grain growth for example as again this is a steel which is intended to hold a razor's edge (literally), on a scale of 1 to 10, it is 10.0 for edge stability.

[xavierdoc]

Depends on what you want, it would be horrible in many respects as it has extremely low toughness, grindability and edge stability. But it has extremely high compression resistance and wear resistance.

Cliff, I always learn from your posts (and many others who post in threads like this) -thank you.

Could you explain the difference between "Low toughness... and edge stability" yet "high compression resistance and wear resistance"?

I think I am getting confused by the nomenclature of blade steel properties!

What would I experience as a user of a knife in Rex121 (perhaps compared to S90v, for example)?

I'd value the answers of anyone else, too, of course.

Thanks again.

[The Mastiff]

Cliff, I'm just guessing that the main form of edge degradation would be chipping or crumbling. At least at the thin edges I like. This is just a guess though. I'm not saying I wouldn't like to try it , just like the 15V blade I'm having made but I don't see it being anything real practical at full hardness.

The charts make it look pretty low on toughness. We'll get reports fairly soon as Farid is making a run of the T1ooo ( ? ) in Rex 121.

[hunterseeker5]

There's nothing lame at all about S125V.

Just kidding mastiff. :P