Battle of the Grinds: Which One Reigns Supreme?

[The_Guide]

I would like to create this thread, that has a place for all qualitative comments on the various grinds/edge geometries that exist in the knife world.

I so often see and hear that convex grinds/edges are better than V-edges, and I also hear the opposite, that V-edges are better etc...

So, anything, and I mean anything you can say various grinds and how they relate to there counterparts has a place here. I am sure a lot of people would really like to hear this debate settled

To get it started, I will add some basic questions (add whatever else you want, even new questions to add to this list, or ignore the questions altogether)


What grind/edge geometry do you prefer?

What is your experience sharpening said grind?

How would you rank the various edge geometries you have tried?

What grind would you say holds a better edge?

What geometry gets the sharpest edge?

What are the Pros/Cons on a convex grind/edge?

What are the Pros/Cons of a V-edge?

What are the Pros/cons of a Hollow grind?

What are the Pros/Cons of a Scandi Grind?

What Grinds am I missing?


You dont have to answer all of these, its just a starting point. Feel free to answer all, one, or none. I really want to see and hear about how all the different grinds/edges hold up against each other.

Thanks!

 

[Jason B.]

This is a never ending story but as far as "best" grind goes my money is on convex. Its hard to disprove the facts of geometry.

 

[Vivi]

Short version: Saber grinds for choppers (Keeps weight forward), full flat for slicers. Thin edge bevels on everything.

What grind/edge geometry do you prefer?

Full flat grind with a thin, convex edge bevel for folders and small fixed blades. For large chopping knives I like saber grinds with a thin convex edge bevel. The saber grind keeps more weight forward, which increases chopping efficiency.

What is your experience sharpening said grind?

I find it easy. For touch-ups I use a microbevel by sharpening freehand on a Spyderco white ceramid rod, followed by a strop. This takes me no longer than a minute. After doing this a few times, to reset the entire bevel I use a mousepad and 800 grit sandpaper, then polish with 1000 then 2000. This takes about 5 minutes.

How would you rank the various edge geometries you have tried?

I'm not going to do a list, but I will say I've never personally had a reason to use a saber grind on a knife with a blade under 7 inches or so. I don't pry with my knives, and while Spyderco creates a good combination of cutting ability and lateral strength with their saber hollow ground blades (Pacific Salt for example), I'd still prefer a higher hollow grind or even better full flat grind. I really don't like saber flat grind (Endura 4), which generally leave the edge much too obtuse for my uses. I prefer the full flat for "slicers" because it's easier to control in cuts for me than hollow. One nice thing about a hollow grind is when I reprofile the edge bevel it takes less time since there is less steel behind the edge.

What grind would you say holds a better edge?

What geometry gets the sharpest edge?

I've noticed no advantages or disadvantages in sharpness or edge holding across various geometries (And I've compared quite a few), except for one thing. The thinner the edge, the easier it is to get sharp and the longer it will stay sharp. The former is explained by there being less metal to remove, the latter I would attribute to less force on the edge during a cut since the thin edge will penetrate media better, but that is only a guess based on casual observations.

What are the Pros/Cons on a convex grind/edge?

What are the Pros/Cons of a V-edge?

Pro for convex would be the nature of the grind pushes material away from the blade when cutting, which can reduce drag. Really though it's not very important in my experience whether you use V grind or convex, what's important is that you have the thinnest edge possible for the work said knife will perform. When I used V edges I'd still convex the top of the edge bevel for slightly better cutting performance, so I decided I'd save time if I just did the whole bevel convex from the beginning, which I do. I say give both grinds a fair shot, and stick with whatever is easiest for you to maintain. Just keep the edge THIN!

 

[firebert]

In no particular order:

For most things, I prefer a full-flat grind with .015" edge thickness and a 30-degree inclusive edge bevel convexed back to the primary grind. It slices well but isn't extraordinarily weak.

Full hollow grinds (straight razor) displace the least material therefore slice better but are very fragile. Thick convex grinds displace the most material so they slice poorly but they are very durable. It's always a trade-off. (Actually a paper-thin blade would be the best slicer and a thick V-wedge would the the worst, but neither are practical.)

I'm a big fan of always rounding the shoulders between primary and secondary bevels (convexing). That metal does nothing to support the edge and gets in the way during slicing. It also makes touch-ups easier because you have to remove less metal to get to the edge.

The thinnest geometry is the sharpest, of course. There are limits, however. The limit is based on the steel and usage. If your edge is chipping or rolling too much, go thicker.

I divide cutting ability into two categories: edge sharpness and displacement. Edge sharpness determines how easily you shave hair, push-cut paper, or slice into a tomato skin. It's based solely on the angle and finish of the very edge. Displacement is how well the entire blade passes through an object. Think of cutting an apple or onion. A thick blade will be more likely to split and break the object rather than pass through smoothly. Thin primary grinds and convexed shoulders improve displacement characteristics. I prefer each of these categories to be as thin as possible without suffering damage.

 

[Joshua J.]

All good none best?

Convex gives you good cutting performance without sacrificing too much toughness. Hollow gives you the ideal edge for shallow slicing. Flat is just nice all around.
No one grind can be made sharper than another, that's determined by your final edge angle and level of polish.

I manage to give everything I use a convex edge, simply because I'm human and can't hold a knife perfectly level when I'm trying to sharpen it.
The convex edge has worked well enough for me, though the shape of the edge isn't as important as getting it thin enough to cut really nicely.

+1 on what Vivi said. Keep it thin.

 

[Joshua J.]

(is it just me or is this starting to look like a darksiders meeting?)

 

[richard j]

i tend to like a half convex edge on the chisel grind knives i make since it seems to work the best. i leave the decision of what kind of edge i put on a customers knife thats sent to me for sharpening up to them. when i started making knives in the early 90's almost every knife i made was a full convex blades but most people wanted a v edge on their knife so they could sharpen it theirself. for durability and ease of sharpening i like a convex edge myself on any blade.

 

[walleyeguy7]

i prefer v grinds, but not scandis. and no chisel grinds. i do like convex and all, but i just plain prefer v grinds at this point. hollow grinds are very vidually appealing to me but most of my best knife experiences are with flat grinds, especially in 7+ in blades

 

[smitty0331]

I tend to prefer flat grinds because I like to get a fine edge on my knives. I'm not a big fan of hollow grinds. Also, I agree that it's hard to beat a good convex edge.

 

[firebert]

(is it just me or is this starting to look like a darksiders meeting?)

I'm sure the Busse guys will show up with their sharpened pry-bars soon enough.

On a more serious note: I steer clear of chisel grinds because I'm left-handed. Even if I make one for myself, no one else can use it properly.

 

[Daniel Dorn]

I won't spend a lot of time covering a whole lot, but just offer up my opinion on what I like.

I love a high hollow grind, all the way to the spine, with a very thin profile. I like my knives to be slicers, and I usually don't do a lot of heavy duty work.

Right now, my favorite grind is a high hollow regrind done by Tom Krein on my Kershaw Blue Bump. It's very easy to sharpen, as the thickness behind the edge is right at 0.010" He can go even thinner, if you like. I like a mean 30 deg inclusive back bevel with a ~40ish edge. Again, I like to slice.

Daniel

 

[Carney C]

Richard, I have always sharpened V grinds on Whet rocks and ceramic rods. Once you convex my blades what will I have to do to keep them convexed? This may sound dumb but I am a "sharp- a- holic", and I don't want to have my new covex back to a v grind in a weeks time. Really how do I adapt?

 

[Vivi]

Well it's not a Busse, but even sharpened prybars can be made hair whittling sharp and given good edge geometry

If anything a thin edge is even more important for a knife like this. You can cut the time it takes to chop a log like this in half by taking the edge down.

 

[p_mcmanis]

I like full flat grinds.

I convexed a little lockback and thats pretty cool, but like all things how sharp it is comes down to experience and I really only have experience touching knives up by running them down the stone a few times.

 

[richard j]

chuck, i'll send you a video on a cd that will show you how to sharpen it by hand whenever it needs sharpened and i'll send you some abrasive cloth to use.