SOG KIKU 7.5" OU-31 Steel Blade

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BabyJWuu

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ku01.jpg


http://sogknives.com/store/KU-01.html

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.
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I have never heard of OU-31 before, is this the new knife super steel?

OU-31 - PM tool steel, attainable working hardness ~64HRC. Several companies made or tested this steel for their knives, including Spyderco and SOG. Also, a few custom knifemakers reported to tested or used it.
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The knives are certainly expensive enough :thumbdn:

http://www.knifecenter.com/kc_new/store_detail.html?s=SOGKU01

Cordially,

BabyJWuu :)
 
I even like Kikuo's stuff better than the SOG collabs, for less $ to boot. BTW, I just bought one of his Wakaba mini lightweight utility knives in OU-31 for edc so I should know what it's like to sharpen 64HRC in a few weeks! I'm sold on the Japanese abrasive paper on a mouse pad followed by the loaded leather strop so I don't foresee any problems.
 
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Gator97 said:
Japanese abrasive paper? Can you please provide more details on that?
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It's just high quality "sandpaper" that happens to be Japanese. Eagle brand waterproof abrasive paper Tokyo Japan. The logo is a double headed phoenix looking thing with the "KSF & KO" across the body. IIRC, I purchased it on Amazon and it wasn't expensive but it's durable and works well.

BTW, I got the Kiku knife in OU-31 and it's been my EDC since the day it arrived. No real testing so far, but I love the design and the aesthetics of the grind, the etching, and the textured micarta handles. Hair-popping sharp out of the box, nice convex edge, stropping seemed to improve the edge slightly.
 
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I haven't had my OU 31 knife tested for hardness but it sharpens very easily with a crisp, easy to remove burr. It gets sharp pretty easy, and has a toothy feeling to it.

No hard, subjective results here but I do have an opinion on it. It's just steel. Nothing magical, but it is high quality, clean stuff that runs good at higher hardnesses like many Japanese steels.

I'd put it closer to ATS 34 than to ZDP 189 performance wise. No insult there, just different steels. It very well might be a high speed steel.

My knife is a fairly small utility type knife. I'd like to try it in a folder.
 
this knife will probably not increase in value in the collector market. at this price you can buy many custom makers that will give fantastic performance & have people standing in line on the secondary market. i.m.o. when spending this amount of money one needs to consider in future they may wish to move in another direction. people change as they age & your tastes may change. of course wealthy individuals may not consider this a detriment.
dennis
 
0.9% Carbon
3% Vanadium
8.2% Chromium
2% Molybdenum
3% Cobalt

There's your composition. It's pretty mustard. 3% Co is loony toons to me. I guess you could say a draw back would be the low C %. You'll have to keep the blade oiled well to prevent corrosion but that's no big deal.
 
I don't know much about metallurgy, admittedly, but a steel with only 0.9% carbon that is usually hardened to 64 HRC sounds unusual.
 
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