Maxamet: Odd behavior. Ideas? Sal?

[RustyIron]

Maxamet has been quite an adventure for me, figuring out how to sharpen it nicely, learning what it can do, and having fun doing it.

Last week I had some strange effects, and I'm wondering if some of the experts care to comment.

The edge was sharpened to an exquisite 30 degrees and had only been used for trivial tasks like cutting tape or cutting/stripping a few small wires. Then I needed something 1/4" thick. I whipped out my Manix 2 LW in Maxamet and made two 4" cuts off the corner of a soft, squishy, quarter inch thick floor mat. It was like a warm knife through butter, and really made me smile. Eight inches total cutting on 1/4" rubber.

Before putting the knife away, I felt the edge and detected quite a bit of damage. Bummer. When I got home, I immediately went upstairs and put the blade under the microscope. The resulting images were interesting. Check out the three attached. One shows damage at the apex. Although disappointing, I wasn't shocked. In the past, this blade has exhibited a propensity for chipping. But the part that was shocking was what appeared to be spalling along the bevel, far back from the edge. There is material gouged out of the flat part of the edge! How could that be?

My experience is not vast, but this spalling is nothing I've seen before on a knife blade and not something I would expect to see. What do you think?

[SteveMidwest]

I could explain picture #1. But then after looking at Pic #2 and #3. I'm scratching my head.
My first thought, is that a 'fold' of sorts, was in the metal from the rolling process. But the chances of that being in that exact spot, in the secondary bevel. Is quite unlikely. I'll sure be interested to find out what the explanation is, after it gets back to the factory for analysis.

[bearfacedkiller]

That second and third pic are head scratchers. Not sure.

Maxamet is interesting. Maybe it is temperamental during heat treat. Reports are all over the map. I have used it normally like I would use any other steel and have had no issues. Seems like there are quite a few people with different experiences. Lots of factors at play so hard to say what is going on.

I look forward to seeing what we learn from this.

[Ankerson]

Will be waiting to see what Spyderco finds out.

[Doeswhateveraspidercan]

Are you sending this into Spyderco? I would so they can give you some feedback.

[Theldraskien]

I experienced some similar edge damage to pic 1 on my Maxamet native cutting some relatively thick wire twist ties. It was the factory edge and I figured it was user error on my part because I put too much lateral force on it. Sharpened it out and haven’t seen any issues since, but I also haven’t tried cutting those ties since then. Only cardboard, packages, that kind of thing.

Someone (Nemo I think) described maxamet as “brittle as ceramic” and that was the impression I got, at least of the factory edge in my Native.

[VooDooChild]

I just got my maxamet pm2 and now you are tempting me to kick the crap out of it.

Way too many variables. Make your maxamet blade the same as a steel blade with everything else being equal and put them to work.

[sal]

Hi RustyIron,

Has to be in the steel or in the cut. What was the wire made of? was it a slicing cut or a push cut?

You can send it to us and we an figure it out, but we'd have to have the knives under our glass. Sorry. You could also resharpen it and hide-n-watch?

sal

[RustyIron]

Has to be in the steel or in the cut. What was the wire made of? was it a slicing cut or a push cut?

Hey, Sal.
The wire was just little 18 ga. copper wire. I just mentioned it in the interest of 100% disclosure. It wasn't the wire, but the mat that was the cause of the strangeness, I have no doubt.

You can send it to us and we an figure it out, but we'd have to have the knives under our glass.

Too late for that. The edge was restored immediately after I took the pictures. But thanks for asking. Maybe next time. My reason for posting was primarily for my own education. After all, there aren't many people on my street... or in the city... who I can turn to for sharpening advice. And I'd have to go further to find someone who puts an edge on uncommon alloys. You guys are right here atop my desk, 24/7, so if I learn anything beyond my own experience, it's going to be here.

[The Mastiff]

Excellent photography Rusty Iron.

None of us can tell all that much just from images in a forum but we do know a few things in general.

Maxamet is not tough nor high edge stability. 30 degrees inclusive is out of my comfort zone for such a high carbide steel at pretty high hardness. Running it thin and then torquing on it can do some damage rather quickly. The strength of the steel from the high hardness can fool a person into harder use than the steel can actually tolerate.

It sort of looks like it was folded back and forth almost like a burr . I admit it's a strange one though. I'd be trying the same cut but with a thicker edge and with 35-40 degrees inclusive instead of 30 to see if something similar happens. Make sure all the damaged steel is removed before applying the new edge. If any damaged steel is still lurking in there you can't make any real judgements on future use of that knife.

If you do have trouble most of us here would be watching for the results of testing done at Spyderco's lab facilities so if you do go that route please update this thread . We do like unusual things here. :)

Joe

[The Meat man]

I'm not sure what I'm looking at in the last two photos. Is that actually Maxamet steel gouged away, below the apex? Judging from the photos, I'd say it looks more like some foreign material from whatever you were cutting adhering to the blade. But it's hard to tell from just the photos.

I keep my Maxamet Native at 30 inclusive and I've not had any major stability issues even when cutting wire or whittling very hard wood.

[The Meat man]

.... I have used it normally like I would use any other steel and have had no issues...

My experience as well. Sharpens great too. It's certainly nothing like ceramic, at all.

[sal]

Thanx for the kind words RustyIron, You are now part of this group that peels back this obscure onion and tries our best to share what we learn.

sal

[jpm2]

I'm not sure what I'm looking at in the last two photos. Is that actually Maxamet steel gouged away, below the apex? Judging from the photos, I'd say it looks more like some foreign material from whatever you were cutting adhering to the blade. But it's hard to tell from just the photos.

Those were my thoughts as well.

I had some of the 1st image in my early use, along with chipping, but eliminated both completely sharpening at ~35 degrees inclusive. I should go back to 30 now with a dozen or so full sharpenings on the edge and see what happens.

[RustyIron]

Judging from the photos, I'd say it looks more like some foreign material from whatever you were cutting adhering to the blade. But it's hard to tell from just the photos.

Y'know... you might be right. That makes infinitely more sense.

As I sit here typing this, I can carefully clean a blade and look at it under the microscope. It looks great. Then I barely rub the blade against my skin, and the skin cells make the edge look like an old hacksaw. Perhaps I misinterpreted what I thought I saw in the scope.

Thanks everyone for getting me pointed in the right direction.
Rob

[kodai78]

Can you obtain another piece of the material? You could cut it and see if you have similar marks on the bevel. If you do then they should come off by cleaning or wiping on a rag.

[RustyIron]

Just an update. Someone reading this thread might come away with the impression that I had a negative opinion of Maxamet. That would be erroneous, as I was just asking about some strange observations. I've been carrying this knife for five month's and my experience has been both positive and fascinating at the same time.

So after cleaning up the edge and using the knife since the first post in this thread, I put it under the scope this evening. You can see an attached pic below. I think my original "problem" of spalling was really just residue on the blade. I can replicate the effect. Even after careful cleaning with alcohol, soap, and a toothbrush, microscopic junk remains and it looks weird under magnification. The edge damage in the original pictures is probably the result of me just being too aggressive when I should have been more careful. That's ok, as the only way we learn limits of machinery is by pushing them.

Tonight's picture is consistent with my previous experience. After nearly a week of use, the edge isn't as sharp as it was, but it's still QUITE respectable. To the naked eye, it's mirror like. Under magnification, it's very interesting. If you look at the scratches, they're mostly parallel, which tells me the edge is pretty flat, until it gets REALLY close to the apex. Wear would make the scratches less consistent. If you look at the apex, there is a little sawtooth action going on. That's not surprising, as if we were to graph strength, the closer we get to the apex the strength approaches zero. But the sawtooth edge isn't noticable.

Overall, I'm pleased with this knife and it's the one I want to carry every day as my beater. Even on the weekends when I should be a gentleman, I still want to carry the beater. Considering my happiness with this knife, I find it interesting that there isn't more hype and buzz about the material. Is it because it's initially confusing and difficult to work with? Or is it because other materials leave it in the dust? I have another Spyderco with the supposed latest and greatest steel coming in the mail. On the one hand, I hope that it's even better than my Manix 2 Maxamet. On the other hand, I hope it's not, because I don't want to give up my gray, patina'ed everyday beater knife.

[sal]

Hi RustyIron,

Thanx for the update. You better be careful lest you become one of those Edge Junky's.

sal

[RustyIron]

Thanx for the update. You better be careful lest you become one of those Edge Junky's.

I sure hope not.
Generally, I like my knives like I like my women: one at a time.
The one in my pocket is my favorite, and I want no other.

With that said, this morning's email brought a shipping confirmation
on a new knife with a fancy name and burnt orange scales.
Could be trouble brewing...