Maxamet - the ultimate Mule steel

[Cliff Stamp]

...I forget if I've ever actually taken anything that thin or not.

How are you grinding them?

In regards to edge strength, a common test of the edge by the german knifemakers who grind in this way is that the edge has to be thin enough that it flexes readily if you press it against your thumbnail, if it doesn't do that then you simply are not finished grinding. These are again knives optimized just to cut like the Herder knives. They work very well on foods, ropes, soft-medium woods, cardboards and light plastics but you can damage them on very hard plastics, bone, plywood, etc. . It just depends on what you want to cut.

[Joshua J.]

Double post

[Joshua J.]

How are you grinding them?

It's just about all done on a cheap 1x30 belt sander, and just finished on stones.

Yes the German test you describe is how I knew I was getting really thin, I was initially surprised when ZDP-189 didn't behave any different from anything else in that regard.

They work very well on foods, ropes, soft-medium woods, cardboards and light plastics but you can damage them on very hard plastics, bone, plywood, etc.

At one point I had my Fallkniven U-2 thinned out as much as I could without changing the shape of the blade, and then I tried to cut a pop bottle stem... poor thing.

[Mjc1973]

This is awesome Cliff. It is clear that you have a love for this and to be willing to share results with the forum is the ultimate in unselfishness.

Kinda off topic, I am a budding woodturner and all the tools I use are M2 and hold a decent edge. I love to get my hands on the kind of steels to see there performance. I believe scrapers would be the area I would try first as it is just a flat bar shape that is 0.25-0.3 inches thick. The scrapers actually cut with the thin wire edge left from the grinder. These tools are generally used straight off an 80-100 grit slow speed grinder.

I know I am in a very small segment of this forum would be interested in this but this thread has given me some ideas that I might have to investigate.

[Cliff Stamp]

I believe scrapers would be the area I would try first as it is just a flat bar shape that is 0.25-0.3 inches thick. The scrapers actually cut with the thin wire edge left from the grinder. These tools are generally used straight off an 80-100 grit slow speed grinder.

It is not uncommon to take worn out tools and make very nice blades from them because the tools use cutting steels. Saw blades tend to make very nice large blades and power saw blades make very nice cutting blades of all types, around here they commonly get ground into fillet and kitchen knives.

It's just about all done on a cheap 1x30 belt sander, and just finished on stones.

Are you controlling the heat as that was the first thing that came to mind when you noted what seemed to be ultra-fragility at a decent edge thickness?

At one point I had my Fallkniven U-2 thinned out as much as I could without changing the shape of the blade, and then I tried to cut a pop bottle stem... poor thing.

Unless you grind to failure you can't know where to get optimal performance, though doing it with a U2 is ambitious. I normally suggest an inexpensive machete and kitchen knife because you are not going to care that much when they do fail.

Now to be clear not everyone wants that and a lot of people want more rugged vs better cutting knives, that is cool there are knives made of all types from just pick the guy who makes what you want/need.

[video=youtube;sADSZNSgUdk]http://www.youtube.com/watch?v=sADSZNSgUdk[/video]

I asked Kyley how thin he could make a friction folder after a video where he was talking about light weight knives and that is what he came up with. The handle is as minimalist as the blade. Now could I break this - yes easily it has no where near the strength/durability of the Pretium from Ferrium Forge but it is only a fraction of the weight/size and still very capable over a broad range of uses.

[Joshua J.]

Are you controlling the heat as that was the first thing that came to mind when you noted what seemed to be ultra-fragility at a decent edge thickness?

I was just having trouble remembering how things went back then.

Here's a post of mine from 2009.

I don't think .010" is too thin. My ZDP Caly 3 is .002" (re-ground flat with the primary grind). I've been using it for over a year now with no problems.
It should be noted that I use a ten to fifteen degree (per side) micro bevel, which keeps the edge fairly durable. When you try to maintain the edge at the same angle as the primary grind, then you have trouble keeping it together in normal EDC.
I guess it's kind of a given that I never pry with it, but that's what the stock E4 grind is for.

[Cliff Stamp]

The heat is critical, especially as the edge gets thin because it then has no ability to heat sink and the temperature rises very easily, if you couple this with water quenching then you can easily end up with a very fragile edge, much more so than the thickness itself would dictate. A number of makers have spoken out about this, Roman Landes for one, and fortunately it is becoming more commonly advocated, especially with the ease of fluid cooling systems available. But still there are people who believe things like :

-if you don't change the color you didn't damage the steel
-if your fingers don't burn you didn't damage the steel

neither of which are true, and both of which ignore basic physics.

There is quite a bit of discussion about very thin edges and use on the forum, even chopping blades are being made in the 0.010"-0.015" range and user edges are commonly < 0.005", but again you really need to be wet grinding in that range and they are cutting tools first. The limit of that grind is made by Herder as those German knives are essentially zero ground with a micro-bevel, anyone who is interested in cutting performance needs one of those as a reference if for nothing else.

There are a lot of custom makers doing some very extreme things as well, Kyley Harris for example has a utility blade that has the spine at a thickness that most people consider thin if it was on the edge of a high performance knife :

[video=youtube;ZpW8qdSZNpc]https://youtu.be/ZpW8qdSZNpc[/video]

Again it is just a matter of finding the balance of durability vs cutting ability that suits your needs/desires.

[Mjc1973]

Cliff,

Does Kiley have a website for his products? If so could you throw up a link. It may not be allowed.

[Cliff Stamp]

He has a website but he is most active through his YT channel as he posts videos like the above of new products and is fairly responsive to messages/PM's.

[Joshua J.]

The heat is critical, especially as the edge gets thin because it then has no ability to heat sink and the temperature rises very easily, if you couple this with water quenching then you can easily end up with a very fragile edge, much more so than the thickness itself would dictate. A number of makers have spoken out about this, Roman Landes for one, and fortunately it is becoming more commonly advocated, especially with the ease of fluid cooling systems available. But still there are people who believe things like :

-if you don't change the color you didn't damage the steel
-if your fingers don't burn you didn't damage the steel

neither of which are true, and both of which ignore basic physics.

There is quite a bit of discussion about very thin edges and use on the forum, even chopping blades are being made in the 0.010"-0.015" range and user edges are commonly < 0.005", but again you really need to be wet grinding in that range and they are cutting tools first. The limit of that grind is made by Herder as those German knives are essentially zero ground with a micro-bevel, anyone who is interested in cutting performance needs one of those as a reference if for nothing else.

Thanks for that Cliff. Yes, I've been doing almost exactly as described, grind until it gets too hot to touch and (hopefully) before it changes colour.
Though I assume that with HSS you'll have more leeway.
Regardless, I have always been concerned about the extreme edge, something that thin is going to behave radically different from the rest of the knife.

What is your favourite retailer for Herder knives? A reference would indeed be fantastic to have.

[Cliff Stamp]

Yes, I've been doing almost exactly as described, grind until it gets too hot to touch and (hopefully) before it changes colour.

The problem with using the scaling colors is that steels will resist scaling for the same reason they resist rust as they at both oxidization and thus a stainless steel will take much more heat for a longer period of time before it shows the visible scaling. It is also long over heated at the edge by the time you can see anything or even feel anything as the edge is on the scale of a micron, but you would have difficulty seeing even ten times as large.

Though I assume that with HSS you'll have more leeway.

Not as much as you expect because it is fairly easy to actual put the edge above the recrystallization point but whatever you do, don't quench it.

What is your favourite retailer for Herder knives?

There are a few people who carry them in the US, but you typically get large markups. The best way is to buy them from the source in bulk with a few friends.

[Cliff Stamp]

Update :

[video=youtube;UuyXn62B-w0]http://www.youtube.com/watch?v=UuyXn62B-w0[/video]

One thing which might be interesting for the Spyderco Mule project is to look at how little steel is used in these blades, there is almost no tang and thus the steel you need is only half of that of a "regular" style tang. It might be worthwhile for Spyderco to alter the basic Mule pattern on the very expensive steel as it makes a large difference to the raw material cost and there is also no need to drill out/taper the tang as there isn't one.

This is an interesting comparison, note how much more difficult the two knives are to work with, the one at 64 vs 69 HRC. It is obvious Jeremy would not confuse the two in working with them, and would easily be able to tell them apart.

[Ankerson]

Update :

[video=youtube;UuyXn62B-w0]http://www.youtube.com/watch?v=UuyXn62B-w0[/video]

One thing which might be interesting for the Spyderco Mule project is to look at how little steel is used in these blades, there is almost no tang and thus the steel you need is only half of that of a "regular" style tang. It might be worthwhile for Spyderco to alter the basic Mule pattern on the very expensive steel as it makes a large difference to the raw material cost and there is also no need to drill out/taper the tang as there isn't one.

This is an interesting comparison, note how much more difficult the two knives are to work with, the one at 64 vs 69 HRC. It is obvious Jeremy would not confuse the two in working with them, and would easily be able to tell them apart.

People wouldn't be able to do anything with them until they had handles custom made...

With the Mules as they are now they can be used out of the box if people want, or they can just wrap tape around them etc....

[Cliff Stamp]

There may be problems with apex stability on the 69 HRC ones, time will tell :

[video=youtube;Rj2j-zuq-58]https://youtu.be/Rj2j-zuq-58[/video]

[Ankerson]

Interesting really. :)

You have my attention now.

[sal]

Good stuff. Edge-ology 101

sal

[Cliff Stamp]

Good stuff. Edge-ology 101

Sal if you are planning on using this steel I can send you one of both and the HT protocols I had used on them and you can CATRA, Q-fog or whatever you want to do with them if it helps you decide on what you want to do with the mules you are going to make, if you are going to make them.

[sal]

Hi Cliff,

We'd be happy to throw it on the CATRA for you. They're still making our batch so it will be a while before we get some. We can send it back to you when we're done. Any info you can proivde would be good. There's not much history on the stuff as a blade steel.

sal

[Mjc1973]

What a great company and forum!

[Cliff Stamp]

What a great company and forum!

Indeed.

Sal, thanks.

For those interested, I have also been asking Jeremy to compare how he works with these to other blade steels in the comments. Just take a few moments to read through them to get an appreciation of how long it takes to work (grind, drill, cut) this steel compared to a more "normal" steel. For perspective, this steel is more of a carbide replacement than it is a steel. It is extremely high carbide.