Chisel ground good/bad????

Runsalone

Runsalone

Joined
Oct 22, 2003
Messages
1,150
I just chisel ground a cheapo to see if I could. (polishing and stropping now) could anyone explain the advantages/ or disadvantadges of this edge geometry??

Any help is much appreciated!!!



Chisle chizal chisal chisel chisele Hell you guys know what I mean:rolleyes:
 
I'd say it's not better or worst....just different :) I like it on weapon grade knives only as it isn't the most versatile edge for utility.
 
I'll secon that, well sort of anyway. I have no clue about what is better for use in a knife intended to be a weapon. To me the chisel edge just isn't as good as a normal ground knife for utility purposes.

Advantages of chisel:
stronger edge
easier to sharpen
sharper

Disadvantages:
cuts to one side
hard to sharpen if you don't have experience


These aren't really my opinions, just what is commonly said about chisel grinds. Personally I don't like them, I find them to be a PITA for a using knife. If it is a better grind for a weapon, well that's fine, but I don't intend to use my knives as weapons, so that doesn't really concern me.
 
Chisel grind is used on japanese chefs knives so that they can easy and very thinly slice food. It's also a good grind for chisels. Other than that I don't see much use for it.
 
Why it is stronger and sharper?
If normal blade has same edge angle what the difference?
Thanks, Vassili.
 
A double ground knife can have the same "relative" geometry as the chisel ground knife, so a chisel ground knif eisn't inherently stronger or sharper. "Typically", chisel ground folders sem sharper because they are ground at something like under 30 degrees and given an edge bevel of around 30 degrees, which is a lower angle than your average knife (40ish degrees).

A chisel groudn knife with no or onyl a slight secondary bevel won't curve to one side as much (or at all).

I actually find them easier to sharpen, if you do them "properly". You sharpen the bevel on your medium stone, raising a burr, then you put the flat back side on your finest hone and to strokes perpendicular to the edge, cutting off the burr. As you can imagine, the finish on the back of the knife will no longer be even or all that pretty, but it will make the knife work better! You then use your fine hone on the bevel for a few strokes, then one or 2 on the back, repeat a few times, then you do alternating strokes a few times (1 on bevel, 1 on back), then you are done.
 
Runsalone, the purpose of a single bevel edge is to cut the bevel angle in half in order to create additional sharpness. In order for this sharpness to be meaningful, the steel has to be hard enough to support the more acute angle without the edge folding in use. It's probably a good bet that your "cheapie" won't be able to take advantage of the more acute angle.

Single bevels are good for a straight slice. That's what the Japanese do with their single bevel kitchen knives. It provides less control and accuracy for other kinds of cuts. Best of luck with the project.
 
Sharpening a chisel ground knife can be ambiguous compared to sharpening a chisel. Crayola's method is common, but there are other methods.

New Livesay's instructions on my neck knife (~ 2 1/2 inch chisel ground 1095) indicated it should be sharpened on both sides, like a regular knife. Sean Perkins (~ 1 1/2 inch chisel/convex ground A2, differentially hardened) says his knife should be sharpened at the most acute angle possible only on the flat side of the blade. I followed the instructions, and both methods worked.

As a cutter, I prefer the Perkins knife, mostly because the blade is thinner, harder and I believe the convex contour is helpful. The Livesay is softer and does gets edge damage fairly easy, per Knife Outlet's observations. These knives are used only for utility purposes, thus I would say chisel ground knives can serve a variety of non-weapon purposes. The Livesay is also used for knife throwing and sticks pretty good in a tree.
 
Knife Outlet :

Runsalone, the purpose of a single bevel edge is to cut the bevel angle in half ...
Click to expand...

There is no difference in included angle when sharpening one bevel at 20 degrees or both sides at 10 degrees. Chisel ground japanese knives have typically very acute and fine and acute edges by choice, it has nothing to do with them being chisel ground. You can easily make the knife into a v-ground edge which is thinner and more acute.

At the same included angle a chisel ground is weaker than an even v-grind because of the imbalance in force, Jeff Clark demonstrated this awhile ago cutting some bone. It is easy to understand why as well. Extend out your hand making a knife edge, have a friend push on both sides of your extended fingers. It is easy to keep your fingers straight because the forces are balanced.

Now have him switch to just pushing on one side. Now it is very difficult for you to keep your fingers straight as there is no counterbalance force so you have to provide it which is very difficult and thus your fingers bend much more readily. For similar reasons chisel ground edges will be dented or rolled much more readily.

Single bevels are good for a straight slice.
Click to expand...

Since chisel ground edges are not even in distribution of forces they provide less control during cutting than an even v-ground (or convex or hollow) knife because you have to adjust for the imbalance in the force to maintain a straight cut. Even actual wood chisels will often have a slight bevel on the back (flat) side to allow more control in turning into the wood.

-Cliff
 
aesthetically, chisel grinds allow deeper hollows and convexes on the chisel side, thus the blade looks good. but doesn't look good on the other side tho'.

I found my chisel ground 30 degrees included blade sharper than my v-ground at the same included angle. can't explain it tho'.

I would say it's easier to sharpen for me if it were ground on the right side (I'm a righty) as I use the edgepro. I just strop off the burr on the flat side.

both good but different.
 
I have one chisel ground tanto, it is a very pretty grind as one of the above poster mentioned. It is however not the most usable knife for utility. The biggest problem, and one that I just didn't think of when I bought the knife, is that it is a left hand grind. Being right handed I have a hard time cutting things with the knife. I note this because most of the chisel grind knives I see are left hand grind. But them I can't complain to much because the knife is still a great back up knife for defense..
Patrick
 
spyken :

I would say it's easier to sharpen for me if it were ground on the right side (I'm a righty) as I use the edgepro. I just strop off the burr on the flat side.
Click to expand...

You can do the same thing with a v-ground edge, just alternate the side you start with to keep it even in the long term.

-Cliff
 
I own a couple of EKI's in the CQC and Raven series. I had a CQC reprofiled by a professional sharpener to a true chisel ground edge. That is according to the fella that did it. I told him when I dropped the knife off that it was a chisel ground blade only sharpened on one side. Well get the knife back and am kind of taken aback by the wide flat bevel he put on it. It is a 50/50 or 60/40 edge. The edge grind is as wide as the serrations. Didn't bitch to much at him cause well he is about 80. Point to all this is the thing cuts like an absolute laser blade. I even shaved my face with it and shaving cream. I ain't kidding either. Shaved my face smooth as hell.

I have since had him and his son sharpen a couple of other folders for me but with the more conventional grind and they get them sharper with a longer lasting edge it seems than I ever could. I carry the CQC quite a bit edc and at work although I am alittle leary at work cause it isn't that sheeple friendly. Have to say if the chisel edge is done correctly as this one seems to be it is a robust edge, an extremely sharp edge and I don't find the cut wandering off in any particular direction as compared to my other standard blades. I don't notice a problem sharpening it now and keeping it as sharp as it is either. Before the Emerson edge would kick my butt when trying to get that hair popping sharpness everyone talks about and likes on a knife. The fella made a point of telling me too when I picked it up that it now has a true chisel ground edge on it too. The edge I would estimate on it was around 37-40 degrees of angle originally. Now it is more like 20 with no pronounced beginning to it. You know the sharp definition between the plunge grind and the edge grind. The other difference I notice on this knife is that the back of the blade doesn't appear to have anymore than a hairs width if that of back sharpening to it. The stropping effect everyone talks about to take off the burr.

I have a very hard small smooth Arkansas stone I use on it now to keep it up to snuff. Oil the stone up and a couple of passes on the primary bevel, turn the blade over and at a steeper angle a couple of passes and voila scary sharp again. If you can get by the asthetics of the edge being a bit wider than normal I think this is the way to go on chisel ground knives. Just my 2cents worth. Keep'em sharp
 
In general it is *much* easier to get a higher degree of sharpness when edge angles are reduced, this is simply because people measure sharpness by cutting ability, and the cutting ability increases when the edge angle is reduced. Thus if you take two knives with the extact same sharpening, and one at 40 and the other at 20, the one at 20 will vastly outcut the one at 40 and thus will score sharper at almost any measure of sharpness.

-Cliff
 
(I'm a righty). I would find chisel ground blades more versatile if they were ground on the right-side of the blade since I do more slicing rather than paring. Form follows function, please! Damn with the cosmetic influence of grinding the left-side of the blade for photo ops or "visual cues."

I think Emerson said that the chisel blade cross-section will offer less resistance when used to penetrate/puncture something as opposed to a V-grind blade cross-section. Assuming that both blades are the same thickness, that claim makes sense.

When I use a Japanese kitchen knife with a right-side chisel grind for slicing (especially vertical cuts), it seems that the wedge (on the right) automatically separates the cut piece away from the whole item being cut. I consider this a time-saver.

My answer to your question? Chisel ground blades can be good if done right. I love my CQC-7B and assorted chisel ground kitchen knives.
 
Cliff I agree. But my point is that the fella said that it is now a true chisel grind very much unlike the edge that EKI puts on there knives. I haven't really talked to him or his son about it though. I would suspect that this is the type of angle put on a flat wood chisel, if there is such a thing. I am not a woodworker so I don't know for sure. To me it reminds me of my fathers hand plane blades. The other thing I notice is that on the back side of the blade where everyone says to strop it at a low angle but don't hit the primary grind by laying it to flat: well this knife has no real back edge to it. I mean if you consider a shiny area along the blade that appears to be less than the thickness of a hair an edge.

By far this is the easiest cutting knife I own. I have knives that will easily shave hair etc. etc. I have others that seem to have a scalpel edge on them so they really bite when shaving hair. This thing just cuts with very very little effort. It has a very high polish to the edge too. Well as always keep'em sharp
 
longbow :

... strop it at a low angle but don't hit the primary grind by laying it to flat
Click to expand...

If you do this you are just creating an uneven v-ground edge. True chisel ground blades are lapped flat on the back just as found on chisels. Yes this scratches up the primary grind, however if you are polishing the edge then this raises the finish as you end up lapping very fine, typically 8000 on a waterstone and then CrO or diamond paste for wood chisels. The reason people say to lift the blade up is that is *dramatically* speeds up the process as you are creating a micro-secondary edge bevel. In general sharpening secondary edge bevels speeds up sharpening and is the optimal way to sharpen. Lee discusses this in his book on sharpening.

-Cliff
 
Here's a new angle to this debate -

Has anyone tried converting an Emerson knife from one-side sharp to both? Given that they're all v-ground, I would think that changing it from one to two side sharpened wouldn't be so hard, but I have no evidence of that. Any here every try it? What happened?
 
Originally posted by csp20108
Has anyone tried converting an Emerson knife from one-side sharp to both?
Click to expand...

I've heard about someone buying a used Emerson that had that done with a Sharpmaker. Unless a lot of reprofiling was done, it'd probably make for a thicker edge. I have no idea how the thicker edge would balance out with increased control.
 
Originally posted by csp20108


Has anyone tried converting an Emerson knife from one-side sharp to both?
Click to expand...

Yes I had it done to my commander. I had a local sharpener here grind the other side for me and then I just touched it up on my 204.

It cuts well enough however I've never been able to get it shaving sharp.
 
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