Hollow Ground and Full Bevel Ground Blades

[Optimus Prime]

What is the differance in the two and are there any advantages of one over the other???

Thanks in advance - OP

[5KNIVES]

Prime,
Good question, tough to answer without graphics. I'll do the best i can with what I have to work with.

First lets start with something else.

Imagine or draw a letter "V" (okay, 21 st century, type a capitol V on your keyboard. The top of the V if it were closed would be the back or spine of the knive. If this were the cross section of the blade, we would have a true "flat grind' all you would need to do to sharpen the knife would be to lay it flat on a stone, and grind away untill it was sharp.
So far so good, easy to sharpen. a plus. slow to sharpen, a minus.

But to cut well and not drag in the substance being cut, we want the blade to be as thin as possible in the area of the cutting edge. So our "V' would have to be very tall meaning a very wide blade, if it were to have good strength and thickness at the spine. Blade would get very wide and heavy in relationship to it's strength. and to sharpen it would require removing metal from the whole blade. Not a good idea. As you can see making the "v" angle greater and we would have an axe blade or a wedge, not a good all around knife edge.

Bevel grind,
Here the 2 sides are parallel, and at some convenient place we grind a bevel to finally reach our narrow v edge. Less metal removal to sharpen, lighter narrower blade, less drag when cutting. This or a variation is what you find on most hunting knives. It's usable. Still the thicker the blade, the wider it has to be to eventually get our 18-22 degree edge angle.

Hollow grind,
Instead of the blade cross section being purely perpendicular or tapered, they would be bowed into each other for maybe the bottom 1/3 of the blade, then might or might not swell out just before the edge. this would be a concave grind, spine can be thicker for strength, light weight, low drag (in the "hollow") when cutting, thinner stock can be used because the hollow portiion stiffens the blade same as a fuller (Blood groove). See a hollow grind on a lot of lower priced kitchen and "hunting" cutlery. The big problem is that with repeated use and re-sharpening, you eventually sharpen away the edge material in part of the blade and start working on progressively thicker parts of the 'hollow", then eventually sharpening can get very difficult. Rarely found on high quality knives, the swelling at the top of the "hollow" prevents deep cuts or slashes. But cold steel uses a hollow grind on the Voyager series, as do many other quality mass mfrs. IMHO it sounds better than it works in practice. "Catchier" i quess,

Actual edge geometry is another whole story.

sincerly hope this is of some help.

[Optimus Prime]

5KNIVES , thank you........once again you have educated me. And yes your post makes alot of since to me. :up:

[ZEKE/PA]

First off, I will agree with what 5knives has stated.
A few years back,I was a semi- professional knife maker.
My first knives were bevel ground but later I built a belt grinder to hollow grind.
By using different belt grits, I was able to eliminate a lot of hand polishing.
Hollow ground knives can be sharpened like razors, BUT, one must remember that the knife is a cutting instrument only.
If you insist on splitting the pelvis bone on your buck, use an ax back at camp.
Regards, Zeke

[5KNIVES]

Zeke

Amen!
Knives are to cut with!

Amen, Amen about splitting pelvic bones!

Sorry to hear you've joined the multitude of former knife makers. You're in good and talented company (excluding me of course, I've never done anything especially well). but I've seen 2 or 3 local guys over the years do excellent work, and just not be able to continue economically. Something wrong with our culture i think, for that to happen.

Seems to be true of most skilled craft occupations. Cabinetry, etc.

Damn Shame!

[ZEKE/PA]

Originally posted by 5KNIVES
Zeke

Amen!
Knives are to cut with!

Amen, Amen about splitting pelvic bones!

Sorry to hear you've joined the multitude of former knife makers. You're in good and talented company (excluding me of course, I've never done anything especially well). but I've seen 2 or 3 local guys over the years do excellent work, and just not be able to continue economically. Something wrong with our culture i think, for that to happen.

Seems to be true of most skilled craft occupations. Cabinetry, etc.

Damn Shame!
Try to find a skilled Toolmaker/ Machinist. another dying trade.
Regards, Zeke