About grind

[bluka94]

Hi!

Can anyone explain why the grind is always to wide? It's around 2/3 (if not more) of blade's widh
Why is that? Is it cosmetics or what? Practicaly it's only the spine that's i.e. 0.25". The rest 2/3 (the grind) is not 0.25".

But what would happen if you cut grind widh to the halv (or even little more) of it's usual? Wouldn't we get a thicker/stronger knife?
Advantage/disadvantage with such grind?
Have some knives already that kind of grind?

 

[John T Wylie Jr]

stronger , perhaps. However geometry comes into play.

1/4 " thick stock and short grinds = wedge , which wont slice too well. Chop maybe , but wont much a really fine cutter.

 

[bluka94]

0.25" was just an example.
My question applies to all thickness.
Let's play with the tought...

Anyone else?

 

[knarfeng]

You already got the answer from John T Wylie Jr.: Geometry.

The wider the grind area, the more acute the angle formed. The resulting blade cuts better than an obtuse angle for most cutting jobs.

It has been said, "geometry cuts." It is true.

 

[Cougar Allen]

Another way to look at this is would you like to add some extra width to your knife on the spine side, keeping the full thickness of the spine for that extra width?

 

[Greg]

Hi!

Can anyone explain why the grind is always to wide? It's around 2/3 (if not more) of blade's widh
Why is that? Is it cosmetics or what? Practicaly it's only the spine that's i.e. 0.25". The rest 2/3 (the grind) is not 0.25".

But what would happen if you cut grind widh to the halv (or even little more) of it's usual? Wouldn't we get a thicker/stronger knife?
Advantage/disadvantage with such grind?
Have some knives already that kind of grind?

That is called a "sabre grind" and does indeed give a thicker, stronger blade for the same length. This might be of use in a sabre, but for a small slicing knife the thickness makes for a poorer cutter.

Knives (in general) have the force, when cutting, applied from the edge to the spine. Even in my smallest, finest slicers this is almost 1.5 cm, and breaking that much hardened steel would require much more force than the pivot on a folder would take, and more force than I would be prepared to put on a small fixed blade.

If you want something that strong, are you sure it's a knife you want and not a pry bar or an axe?

Greg

 

[bluka94]

Another way to look at this is would you like to add some extra width to your knife on the spine side, keeping the full thickness of the spine for that extra width?

It depends....I don't want the blade to be to widh. Let's say 40mm. I'm trying to imagine how would it look...
I agree that you would lose on slicing ability, but cutting, choping, stabing shouldn't be affectid...? Or?

 

[bluka94]

That is called a "sabre grind" and does indeed give a thicker, stronger blade for the same length. This might be of use in a sabre, but for a small slicing knife the thickness makes for a poorer cutter.

Knives (in general) have the force, when cutting, applied from the edge to the spine. Even in my smallest, finest slicers this is almost 1.5 cm, and breaking that much hardened steel would require much more force than the pivot on a folder would take, and more force than I would be prepared to put on a small fixed blade.

If you want something that strong, are you sure it's a knife you want and not a pry bar or an axe?

Greg

A sabre grind is it called...?
I found this:

The Sabre Grind

The sabre grind is a strong edge format. The bevel starts around the middle of the blade, and proceeds flatly towards the edge. This leaves a strong edge for chopping and other hard use. But it also means the edge will be fairly thick, so this design will not necessarily slice all that well.

The sabre grind is found on many military classic designs such as the Randall #1 and the kabar.

And I forgot to mention that I was thinking of fixed blades in my first post.
As I can see there are already knives that have sabre grind. I have to take a loook at those grinds....

 

[bluka94]

Here is a pic of a Ka-Bar:

It was something like this I had in toughts. Never mind the "false edge". Imagine the knife without that.

 

[Keith_H]

the thickness of a kabar is about 1/8" i think, if it was 3/16" or 1/4" it would be a wider grind.

 

[bluka94]

the thickness of a kabar is about 1.8" i think, if it was 3/16" or 1/4" it would be a wider grind.

I don't get it...
1.8" = 45mm I never saw a knife that thick.
3/16" = 4,76mm
1/4" = 6,35mm

Do you talk about thickness or width?
But, nevertheless, wouldn't grind be proportional to blade's width, even if blade would be wider? It looks like grind is just 1/2 of blade on that Ka-Bar....

 

[Keith_H]

sorry i meant 1/8" thick.

 

[Juststeve]

For about as thick an example as you will find (proportionally) in a good slicer, take a look at Vox's PryMate -- designed to give a lot of strength and versatility in the blade (hence the "pry" in the name) when other tools may not be practical or at hand: Vox PryMate

 

[bluka94]

For about as thick an example as you will find (proportionally) in a good slicer, take a look at Vox's PryMate -- designed to give a lot of strength and versatility in the blade (hence the "pry" in the name) when other tools may not be practical or at hand: Vox PryMate

Thankx for tip-off, but it's to little for me. I was thinking a blade with these measurements:
-length: 6"
-width: 1.6"
-thickness: 0.25"

Hmmm...his other knives, Rold and MJ seem interesting, however....

 

[knarfeng]

Here is a pic of a Ka-Bar:

It was something like this I had in toughts. Never mind the "false edge". Imagine the knife without that.

Thankx for tip-off, but it's to little for me. I was thinking a blade with these measurements:
-length: 6"
-width: 1.6"
-thickness: 0.25"

Hmmm...his other knives, Rold and MJ seem interesting, however....

I think you are looking for one of these?:
http://www.sheffieldknives.co.uk/acatalog/info_12.html