In geometry (and the "literal" meaning of the word), obtuse refers to an angle of "more" than 90 degrees (right angle), but less than 180 degrees (flat line)

Acute - refers to an angle of "Less" than 90 degrees, but more than 0 degrees.





But, in common language usage, Acute is often used to refer to something with a fine thin angle (or finer/thinner than normal) = more sharp

And obtuse is often used to refer to something with a wide thick angle (or wider/thicker than normal ) = more blunt.

When used referring to knives, the terms are often used to imply "relative" meaning:

For most knives, common sharpening angles typically range from 20 - 30 degrees total (or 10-15 degrees per each side).

So, in the knife world, if a knife had an edge angle of 40 degrees, it would be obtuse.

If a knife had an edge angle of 15 degrees total, it would be very acute.


I have a lot of wood working tools designed to layout certain common angles 45/90 and such, but I don't really have a guage that measure angle on knife blades or similar very well. However, I do have a pair of scissors to mark the angle that I can line up with an old 180 degree protractor. But, my CGDM has a convexed edge which isn't going to be an exact angle since it is curved on both sides of the edge. However, even after a LOT of reprofiling and thinning of my CGDM (I can't do much more without re-grinding the existing primary Saber grind), but:

I estimate my current edges angle to be somewhere between 35 - 40 degrees still. - which is stil very "obtuse".

So, considering I have reprofiled mine considerably, I think it pretty safe to assume my CGDM originally had well over a 40 degree edge angle. - VERY Obtuse!






Yeah... as shipped, you pretty much have it.

It isn't commonly excepted that a 0.28" thick by 5.25" long by 1.375" tall AND with a 2/3 height SABER grind is going to be a great slicer.

Consider the following:

Cutting varies depending on the material being cut. In some cases, all that matters is a good sharp edge - say cutting hairs - because a hair's thickness is SO small, the only factor is the very tip of the edge. The rest of the blade has nothing to do with cutting a hair off your arm.

Paper is thin, so even if you slice through a long sheet of paper, the material is so thin and flimsy that it falls to the side of the blade with very little resistance. So, again, mostly what matters is the very tip of the blade being sharp. Although, friction on the sides of the blade can often be felt dragging on paper.

When cutting thicker and denser materials where the blade's side actually have to push through the material - like a big piece of meat, large vegatables or other vegatation, etc. the thickness of the blade and angle of the blade's edge start to be more relevant factors in cutting efficiency. Similarly, amount of drag or lack of drag on the sides of the blades (coatings) can be a factor in some of these situations as well.

The following are a couple of simple drawings I made up to help demonstrate the differences in cutting (through cutting) between a thinner more acute angle/edged blade vs. a thicker more obtuse angle/edged blade:

Notice how a thinner more acute blade "CAN" (in some cases) have the advantage as the cutting "edge" will be more in contact with the material to be cut to help seperate the material.

Vs. in some cases, a thicker more obtuse angled blade's edge might be prevented from helping to "CUT" through the material. The thicker blade in this case is having to "wedge" apart the material. Wedging material apart can work O.K. in some cases if like logs the material is prone to splitting. But, some materials don't split like logs and sometimes "Cutting" is WAY better than wedging.


Acute angled edge with slimmer blade:


Obtuse angled edge with thicker blade:



I hope that helps in some way.

However, SR-77 CAN take a very good edge. And if some work is put into putting a good edge and a good edge profile on the DMCG, it CAN be a very good "edge" cutting tool..... meaning it CAN cut things well that you would normally only cut with primarily just the edge like paper, straps, arm hair, etc. ...

You have to keep in mind the DMCG is thicker than either your S6 or your SOD while being a LOT smaller in length, shorter in blade height and significantly shorter in blade height grind. So, the edge transition is VERY obtuse even with a good re-profiling.

I have mine sharp enough to "POP" hairs and smooth slice paper into silky slivers or tiny tiny tight little curls. So, it is sharp and that sharp will CUT. But, try cutting through box cardboard or apples and the thickness of the blade and obtuse angle of the grinds make it stick rather than cut or split things open rather than cut through them.

In the hand, the DMCG feels like a half-flattened and sharpened Rail-Road spike with a Res-C handle..... and probably tougher. <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" /> <img src="/ubbthreads/images/graemlins/wink.gif" alt="" /> ... if not the greatest slicer, it is still very unique, quite cool in it's own way.... and One MAJOR BRUTE! <img src="/ubbthreads/images/graemlins/bowdown.gif" alt="" /> <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" />

I honestly don't carry mine much, but I have no plans to let it go either.

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