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"...the Extrema Ratio Nemisis is a "fillet knife on steroids"

(Please click images for larger photos. Photos and comments courtesy of John Allen)

“The technical aspects of the Extrema Ratio Nemisis that were not covered on…

The blade height at the hilt guard measures ¾ of an inch. When compared to the MDC knife, you can see a quarter of an inch increase in height when looking at the two aforementioned knives hilt guard.

The steel - N690Co is a Cobalt-enriched stainless steel from Austrian steel company Bohler. N690 shares some similarities with its other Cobalt-steel brethren such as ATS-55 and VG-10. N690 is similar to a sophisticated 440C with better edge holding and stain resistance. The steel is extremely fine grained. When it comes to edge holding, it is agreed that the finer the steel grain the better.

Composition C 1.07, Co 1.5, Cr 17, Mn 0.4, Mo 1.1, Ni -, P -, Si 0.4, S -, W -, V 0.1 - Values are shown in percentages.

Various alloying elements (chromium, vanadium, phosphorous, manganese, molybdenum, nitrogen, etc.) used in blade steel, particularly in the family of corrosion-resistant “stainless,” produce certain desirable properties (edge retention, hardness, corrosion resistance, impact strength, etc.).

One of the most exotic alloying elements is Cobalt, which is known to increase hardness and strength, as well as intensifying the effects of other elements in a particular steel formulation. Typically, N690 is hardened to a factor of RC 58-60. Obviously, the key here is the addition of cobalt in the steel matrix. The cobalt allows the creation of a very uniform structure within the steel.

And when used in blade steel, this provides a fine and consistent edge, enhancing edge retention and sharpening receptivity. (From

Our best conventional knife steel. Great value in a corrosion resistant knife steel with excellent edge holding capabilities. Additions of chromium and vanadium enhance edge holding capability, while cobalt and carbon help to retain high hardness. Hardens and tempers to 57-59 HRC and 60-62 HRC with deep freeze. For maximum toughness, harden and temper to 57-59 HRC. For maximum wear resistance, harden and temper to 60-62 HRC. (From Bohler Specification Sheet at… (

My Opinion… My Extrema Ratio Nemisis came with the “rough textured finish”. Which equates for me to be about the same as 4000 to 6000 grit sandpaper. Which, to me, provides an excellent grip, without destroying my clothes.

Almost all of my knives have been “customized” extensively to fit my needs. The only customization required, by me, for the Nemisis, was simply bending the pocket clip to reduce the pull necessary to remove the knife from my pocket. Additionally, I had to loosen the blade tension with the supplied allen wrench. That’s all that was required to make this one of the best pocket/fixed blade knives I own.  I noticed in some reviews of the Nemesis that some people were using this knife to open boxes.  The Nemesis is anything "but" a box cutting tool. I would say the Extrema Ratio Nemisis is a "fillet knife on steroids".  I would also caution anyone who uses a folding knife to keep their finger out of the path of the closing blade.

Nancy at www. was extremely helpful, courteous, and professional. I ordered my knife Wednesday and received it Friday. The knife was shipped in a large, well packed USPS box. I could not hope to get better service from a vendor. I would compare Nancy at to the “” of the Extrema Ratio knife product line and highly recommend them. I look forward to future business with Nancy at” John Allen

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