Flat vs Hollow grind

Pete1977

Pete1977

Joined
Apr 15, 2002
Messages
3,376
I prefer a hollow grind, it feels sturdier to me. I do a lot of cutting vs slicing, and I've only owned and edc'd a few flat ground knives.

what are the benefits of the flat grind vs the hollow grind and vice versa?
are different makers' flat grinds better than others?
how about their hollow grinds.

and what are you guys/gals preferences?

Pete

PS-I'm not a fan of the chisel grind, but if someone out there has a preference for it, by all means include it here. :)
 
Scott,
Me too.:thumbup:
Are we talking about fixed blades or folders? :confused:
Doug
 
No hollow grind, never. flat grind for folders and, yes Scott, yes Doug, convex for fixed blades.

dantzk.
 
I like flat grinds and convex grinds a lot, but I use folders with hollow grinds, too (like the Spyderco Endura or Buck 110).

For fixed blades, I wouldn't trust a hollow grind very much, unless it was a small pocket fixed blade which will not be used too hard.
 
I really like the hollow grind on my sebbie's because I only use it for slicking and the like. most of my blades are flat gound. I prefer that to hollow depending on the style of knife.
 
I like hollow ground on a hunting knife. It gives you the thinnest edge for cutting sticky sinewy material. It also works well on stiffer material if you are shaving or whittling material off the surface. If works well on rope.

The scales tip towards a full flat grind when you cut stiff material. For example I would rather use a thin flat ground blade to cut through a credit card than a similar hollow ground blade. In hard material the back shoulder of the hollow tends to bind.
 
I like hollow or flat ground with flat edge bevel in folding knives
And flat ground with convex edge bevel in fixed knives to avoid edge chipping and it's very easy to sharpen them
 
Jeff Clark said:
I like hollow ground on a hunting knife. It gives you the thinnest edge for cutting sticky sinewy material. It also works well on stiffer material if you are shaving or whittling material off the surface. If works well on rope.

The scales tip towards a full flat grind when you cut stiff material. For example I would rather use a thin flat ground blade to cut through a credit card than a similar hollow ground blade. In hard material the back shoulder of the hollow tends to bind.
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Couldn't have said it better myself. Hollow-ground for skinning and field dressing. Not bad for general utility, although flat-ground works better on some materials.

I also prefer a convex edge on fixed blades, since the edge holds up so well to tasks that would otherwise dull the blade quickly. Let's hear it for geometry at work!!!

Peace.
Alex.
 
Pete1977 said:
I prefer a hollow grind, it feels sturdier to me. I do a lot of cutting vs slicing, and I've only owned and edc'd a few flat ground knives.
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You are likely comparing a sabre-hollow to a full flat there and it is the sabre vs full which is of significance.

what are the benefits of the flat grind vs the hollow grind and vice versa?
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A hollow grind allows you to remove more material and thus obtain a higher level of cutting ability in most situations than a flat grind. It also has a higher strength/weight ratio. The drawbacks are lack of ultimate strength and binding can be an issue in some materials. Hollow grinds also don't support the edge well and in prying and impact work they can focus the stress right on the edge itself and induce massive damage.

It is critical to note though that how the grind is implemented makes more of a difference than its type. David Boye flat grinds and his knives cut exceptionally well, much better than many hollow ground knives. Strider also uses hollow grinds and they are very thick and don't cut well but are stronger than many flat ground blades. Look at the cross section more so than the curvature.

-Cliff
 
I stand corrected, cliff. You are right about the saber hollow grind. What I am trying to find out, for example is, when cutting rope, is a blade like a delica (saber?) or a calypso jr. (flat) more efficient?

now for my own clarification, a delica would be a sabre-hollow
a calypso jr would be a flat grind
a straight razor would be a full hollow?

do I get it yet? :)
 
If you honed the Calypso Jr and the Delica to 15 degrees per side I don't think that you would notice any difference between them slicing rope. On the other hand if you decided to hone to a really low angle (say 8 degrees) it would take a lot longer to do on the Calypso Jr. If your arm got tired and you only honed the Calypso Jr to 12 degrees per side while you honed the Delica to 8 degrees you would find that the Delica cut through the rope better. That is really where the performance of a hollow ground edge is noticed. It is just easier to get to a low angle honing a hollow ground blade. That is why razors are hollow ground.
 
Pete1977 said:
What I am trying to find out, for example is, when cutting rope, is a blade like a delica (saber?) or a calypso jr. (flat) more efficient?
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Spyderco typically grinds much thinner and more acute edges on their full flat grinds and thus they cut better in large part due to this difference in edge geometry. The Calypso Jr. in particular is one of the most praised folding knives for high cutting ability. The hollow grinds are usually sabre and thus thicker in profile and are generally on the more robust blades.

a delica would be a sabre-hollow
a calypso jr would be a flat grind
a straight razor would be a full hollow?
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Yes.

Jeff Clark said:
It is just easier to get to a low angle honing a hollow ground blade.
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Spyderco typically does sabre-hollow though and full flat and thus grinds the edges thinner on the flat blades which are then easier to reprofile. If the grinds were of the same height this would be reversed.

-Cliff
 
I prefer a flat grind or convex on a fixed blade like a bowie or camp knife but for a folder it doesn't really mater to me. I haven't trusted hollow grinds on bigger knives since I saw my friend ruin the blade of his Randall bowie cutting branches off a tree in Alaska.
 
GrayWall04 said:
I haven't trusted hollow grinds on bigger knives since I saw my friend ruin the blade of his Randall bowie cutting branches off a tree in Alaska.
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Did the edge bend or break? Do you know if it was stainless or O1?

-Cliff
 
Take a look at what all the custom competition fixed blades are in the cutting slicing chopping and bending contests. They all look the same. What do you think they might be. Hint, not one of them is hollow ground.:thumbup:
 
Cliff, his Randall was 01 and he took a big chip out of it about the size of a dime. I figure it probably had a bad heat treat but still made me not trust the hollow grind on a knife used for chopping.
 
im making a tacticle knife.i read that sabre grind was the best for this and general ranch use. what angle would i make the first grind? then what angle the second grind (cutting edge)?
 
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