Compilation of bevel angles from the manufacturer?
- This topic has 13 replies, 7 voices, and was last updated 09/18/2017 at 11:43 am by
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I don’t believe that you’ll ever see such a list. From what we can tell, virtually every manufacturer puts the final bevel on by hand, relying entirely on the eye of the person doing the sharpening. I recently did a batch of knives for my nephew which were brand new. He had bought them as specials on Woots.com. There were five Kershaws of one type, two Kershaws of another type and two Gerbers of a third type. Every knife had different angles and they even had different angles from side to side. A typical example would be a blade that was sharpened to 18 degrees on one side and 24 degrees on the other.
For what it’s worth:
This last week, I did a batch of nine Wuesthof Classics for a friend. They were all very dull and I could see easily that they had only been sharpened with a steel. Because of this, I could still see remnants of the factory grinds. They too were quite variable in the grind angles. Some edges were well off-center.
27.5 degrees is quite high for an EDC knife. I sharpen almost every folding knife I do to 20 dps. For kitchen knives, I usually do 17 dps for a main bevel, then put on a very light 20 dps microbevel. Boning knives get a 20 dps edge with no microbevel.
Tom hit the nail on the head; every knife is going to be a bit different from the factory so a database wouldn’t be of much use. The precision of the Wicked Edge can be used to correct these inconsistencies to put highly symmetrical bevels on your knives or even to intentionally put unsymmetrical bevels on knives.
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Wide bevels are usually and indication of narrow bevel angles and likewise narrow width bevels usually correspond to wider bevel angles. If you aren’t removing “all” of the sharpie from the full width of the bevel then you haven’t matched the knife’s sharpened angle correctly. Also besides playing with the angle you may need to slide the knife forward or backward in the clamp, or tilt the knife point up or point down in the clamp to remove the sharpie from “all of, and only from” the bevel. AlRon22 to accomplish this it can take a lot of playing around. With experience you’ll inherently know which way to move the knife in the clamp to accomplish this. There is printed/illustrated material on the Wicked Edge website to help you learn how to find the sweet spot.
When you remove the sharpie below the bevel edge or apex and leave some ink right at the edge or apex, you have use a set angle narrower than the knifes bevel grind. In order to remove all the sharpie with this setting you’ll be removing a lot of metal. Maybe more than is good for the knife. So depending on the blade, how far forward or how far back this is happening along the knife’s length, you may be able to correct it and remove the metal and the sharpie right up to the apex by just tilting the knife point, up or down, or by just sliding the knife forward and backward, or by clamping the knife higher or lower in the jaws, or all three, and/or it may require changing the set angle of the wicked edge also. (So there are at least four factors affecting the knife’s position when trying to determine and match the original bevel angle.
Anytime you are not right on the initial bevel the knife had when you first clamped it, any metal you remove, is in essence re-profiling the knife. That is changing the bevel angle. That is not necessarily a bad thing. The issue is, it takes practice and experience to recognize how much your really changing the angle and how it’ll effect the knifes cutting characteristics and durability.
Lastly, if you haven’t removed the sharpie right at the edge of the edge, “the apex” then your not sharpening the edge of the knife. That is you haven’t apexed the edge. The edge is still the unsharpened edge you had when you first clamped the knife.
Marc
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In essence the uneven grind angles can improve the cutting/slicing characteristic and ability of a knife. This issue has been discussed several times in earlier Forum posts so please read these to help you gain insight. The term “non-symmetrical grind” can be ambiguous, too, because it can imply the knife is ground at a different angle on one side then the other or to imply the bevel angle is ground to different angles from one side to the other.
Either way, the steepness of the angle affects the ease of penetration of the edge and also how the cut material is pushed off the edge after penetration. It also can affect how the blade steers through the cut material. A steep bevel, that is lower angle, allows you to cut smaller, thinner, slicers, than a wider or higher bevel angle. A steep narrower angle should penetrate easier using the opposite wider angle side to push the cut material off and away during penetration.
Marc
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Consider the chisel grind and how it behaves as it cuts through a material. If you hold the blade vertical, the blade will follow the non-beveled side of the blade exactly. I have a cheap cleaver that came from the manufacturer with a small bevel on the flat side. If you wanted to slice off a very thin piece of salami, it was hopeless. Unless you were cutting very close to the end of the salami, the edge would drift toward the flat side, preventing me from cutting the salami straight. I re-ground the edge so that it was a true chisel grind and I was then able to cut extremely thin, straight slices of salami. The blade would always cut dead-straight, following the flat side of the cleaver. The bevel on the opposite side of the blade will drive the salami slice away from the cut line.
This concept requires that you know which hand will hold the blade. If the user is right handed, he/she will hold the salami with their left hand. To cut very thin slices, you’d sharpen the blade with the non-beveled side on the user’s left side, as he looks down on the knife’s spine. You can approximate this effect by making the bevels uneven, and you can make them uneven by changing the bevel angles or by removing much more material from one side than the other. Reducing the angle on the “flat” side will enhance the “chisel” effect without moving the apex as far. The blade will always tend to push itself away from the side with the higher angle, as there’s more resistance there.
They call it a chisel grind because it works just like a wood-working chisel. The user knows that if he holds the chisel with the flat side vertical, it will cut exactly along that line. The beveled side of the chisel will tend to drive the chisel toward the flat side. The flat side, the material it has already cut and the user holding the chisel vertical will all work to ensure a perfect, vertical cut.
The above is meant to teach you how the cutting edge behaves. The closer to a chisel grind you get, the more accurately the knife will cut along an intended cut line. Very thin blades are less subject to the effects of an off-center apex.
A simplification of my blather here is that a blade will tend to be pushed away from the side which sees the most resistance. The difference in resistance can be caused by a wider bevel (offset apex), a higher bevel angle on one side, or by the side-to-side difference in density of the material being cut(a thin slice will produce almost no resistance).
For our purposes, these conditions can be used for you or against you. Since the vast majority of our blades are “general use” applications, we try to keep the bevels symmetrical, with a centered apex.
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Just to further complicate it. There are many more uneven bevel grinds then the Chisel Grind: Uneven Grinds
Marc
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