Blade steel hardness matters but with a caveat.

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Viper2

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Mar 15, 2012
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I work at a rope factory and I cut a lot of rope yarn on cardboard tubes. From trying several knives with Aus8, CTS XHP, D2, Maxamet, N690co, VG-10 and Damascus (1095 & 15N20), I’ve come to the conclusion that hardness level does matter to a degree but with a caveat. I don’t know if I’d ever purchase a Maxamet knife again due to difficulty of sharpening it. Ease of sharpening matters too. All these steels have been great except for the Aus8 and Damascus because those two have trouble keeping a sharp edge for very long with the materials I cut. I use knives MUCH harder than the average person because of the materials I cut everyday for my occupation, but I just wanted to share my experience with all of you.
 
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Hardness only matters until around 60hrc, then it's a tossup between composition and geometry. 60hrc is where a lot of your lower end steels start becoming problematic, and the higher end steels really start pulling away from the pack. 61hrc is an even bigger Litmus test, because most of your lower end steels can't even reach it at tempered hardness, and some of your mid range steels can't maintain stability at 61hrc.

I fully get not wanting more Maxamet, though. I did a refined near mirror on Maxamet and S110V just to see how hard it was, and I'm never doing that again. It's not super horrible once you get the bevels set, but it still takes vastly more time to accomplish than any other steel I've used, but being the glutton for punishment I am, I still want to try out Rex 121 at some point.
 
dkb45 said:
I still want to try out Rex 121 at some point.
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I think the Mako CPM REX 121 EDC knife is too hard and would be even more impractical than the Maxamet Manix 2 I have. I mean what’s the point in such a super hard steel if it’s a royal pain in the butt to sharpen? Also, I assume the Mako’s blade would be relatively brittle (for steel that is) and chip relatively easily.

Just my thoughts.
 
It may not have been the high hardness of the Maxamet that led to its difficulty in sharpening, but rather its wear resistance. After all, many people are using kitchen knives in white and blue steels that are 66 Rc and those are rather easy to sharpen.
 
I have to agree, very sensible conclusions.

I use my knives for stripping thick insulation from multi conductor RF cable (8, 16 and 32 channel coax bundles) daily, and Ive found the higher end steels work better as well. All of them from Buck 110 to Benchmade Griptillian, Casbah and Higher end Spidies will do the job but it is a whole lot easier to do it with anything above S30V. When cutting with the higher end steels it almost seems like the blade is lubricated as opposed to the more effort and chatter with Aus8 and 440HC. Only downside is I have to remember to ease back on the pressure or the higher end steels will cut right through the copper shielding.
 
LX and Larrin have it, from my perspective. I use a lot of steels, right up to REX 121. With a thin blade and a thin edge profile -- less than 0.01 inches at the shoulders -- pretty much any steel is easy to resharpen with diamonds.

And with both a hard, high-wear steel and a thin edge geometry, the edge lasts much longer.
 
If it's a work knife I would use a powered sharpener like the worksharp and put a quick and dirty edge on it. That way the performance benefits of higher wear resistance steels don't become outweighed by sharpening time.
 
Viper2 said:
I work at a rope factory and I cut a lot of rope yarn on cardboard tubes. From trying several knives with Aus8, CTS XHP, D2, Maxamet, N690co, VG-10 and Damascus (1095 & 15N20), I’ve come to the conclusion that hardness level does matter to a degree but with a caveat. I don’t know if I’d ever purchase a Maxamet knife again due to difficulty of sharpening it. Ease of sharpening matters too. All these steels have been great except for the Aus8 and Damascus because those two have trouble keeping a sharp edge for very long with the materials I cut. I use knives MUCH harder than the average person because of the materials I cut everyday for my occupation, but I just wanted to share my experience with all of you.
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Pointing out the obvious and what is alluded to in many of the responses....

Rope and cardboard are very abrasive and rope is fibrous. Both of these things argue for steels with plenty of carbides like S30V, D2, or older 440C.

On the other hand, these same carbides will make it harder to sharpen. Sharpening is just intentional abrading of the steel to form a new edge.

Lastly, diamond based stones cut through carbide rich stones more easily.

I think the solution you're looking for involves carbide rich steels and diamond sharpeners.

If you are new to sharpening, I would recommend the Lansky system with diamond stones.

If you are experienced in sharpening and want something for quick touch ups while at work, I would recommend the DMT credit card or Diafold sharpeners. I wouldn't bother going beyond a medium grit for what you're doing.
 
The heat treatment matters more than the hrc. But the hrc is the only thing we can measure. Even so a blade can be heat treated differently and still achieve the same hrc but different properties due to different ht recipes.

In any case I use bonded diamonds to sharpen maxamet with out issues. And diamond paste strops. Easy.
 
If you like D2 and CTS-XHP, take a look at how a high-wear, thin edged steel does so much better in Ankerson's rope-cutting tests:

CPM 10V - 2400 - Phil Wilson Coyote Meadow - 64.5 RC - .004" behind the edge
CTS-XHP - 540 - Cold Steel Ultimate Hunter - 63.5 RC - .020" behind the edge
CTS-XHP - 240 - Military - 60.5 RC
Dozier D2 - 220 - Dozier K2

Not only does the thin-edged 10V at 64.5 Rc cut much, much longer, an edge that thin will be easy to keep sharp.

You could also go with a micro-bevel, which makes edges easier and faster to resharpen, as Sodak's sticky in the Maintenance section explains.

If you're resharpening a lot, I'd stay away from motorized systems because your blades won't last long.
 
I believe that the amount of cobalt in maxamet makes the substrate around the carbides harder. Or so that's what I've read.
 
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