Is that right? 40 degrees? I am not saying I know 100% but an angle starts from the bottom, so it seems 20 degrees per side is still 20 degrees, on each side how does 20 degrees ever make 40? 40 would have to be 40 on each side. Please enlighten me if I'm wrong to think this way. It just seems you don't add two different angles to combine and make 40.
I guess this is how the 20 degree standard chosen by knifemakers perpetuates itself...: I don't hold this against you at all for not knowing this for certain, as
I myself was confused about this for decades.... I've seen even KNIFEMAKERS puzzled by my constant use of the precise 20 degrees
per side term, like they could not figure out that this actually means a 40 degree
inclusive edge (or should I say
wedge?), when both sides of the sharpening angle are added up...
People think that, when they have a 20 degree edge,
conveniently unspecified, their knife actually is cutting with a mean-sounding 20 degree V shape... In fact their knives are twice as dull as anything they can picture in their minds...: A "20 degree edge" is really a 40 degree total angle...: Something that, depending on bevel thickness, requires so much effort to actually cut any thick material that it really is an accident waiting to happen... Oh yes it can slice paper and shave hairs... Big deal.
In the old days, people had their knives scratched up their sides because they laid them flat on the stone, and nobody even had a notion of tolerating the ridiculous edge angles that are accepted today... That's probably because they needed their knives more...
So thanks to this quite
deliberately maintained confusion, a lot of the knife buying public don't even properly understand that the measurement of their edges means they have something any non-knife person would consider quite blunt...: I guess owners, and makers, would not be so thrilled to tout the sharpness of their stuff if they quoted the actual
inclusive edge angle as 40 degrees...
Marketing you know...
The reason for this subterfuge, of course, is that closed angles are more risky for the steel, and make it more vulnerable to visually apparent failure (chips, bends etc), so completely against the interests of the knifemaker's reputation (even Randall themselves very clearly recommends 40 degrees
inclusive, but conveniently stops their diagram's count at 20...: Their out of the box edges are dull in accordance- But at least they are beautifully thin laterally, so, in the immortal words of Gary Randall: "You know how to sharpen knives, don't you?" )...
Actually a true 20 degree
inclusive edge
is getting on the "too sharp" side, and is unforgiving of all but the best steels: 24 degrees inclusive is probably better: So far only my Randall Model 12 in 440B, and my Lile Mission in D-2, have held up perfectly chopping wood at such thin angles... S30V by RJ Martin narrowly failed by making a slight wire edge, but there were mitigating factors, except that the edge was quite a bit more open in angle than the 440B and D-2 blades... Hem... Anyway, unlike anyone here steeped in certainties, I won't make any claims of scientific validity... Be very skeptical of precise rankings that divide steels in a half dozen categories...
As far as the "scientific" aspect of steel testing, just the fact there is so much emphasis here on steel type shows you the scientific foundations of "S3V is better than 440" is quite shaky: I won't even go into heat-treatment, but just consider how "clean" is the steel... Cleanliness is an unknown factor in any steel, and yet it can easily overwhelm any claim of superiority made... How clean is the steel really depends on the source, and there are often many sources... I'll tell you my feeling about it though...: Randall probably uses a
very clean source for that lowly 440 steel...
Just consider that ALL testing of knife edges (tests which the steel manufacturers emphatically don't do, since that is a low-tech specialty) is done with
completely different knives, not even identical test mules, and you get an idea how subjective the whole issue is, this from people who are not always sure what the edge angle they have actually refers to...
Gaston
