Thickness vs width

[Bob Denman]

From an aesthetics perspective: I just like the looks of a wider blade.
But the thickness of that blade allows you to set it up with different grinds, and allows for different edges.
And blade material gives you the toughness that you need.
IMHO...

 

[WeekSecret]

Let's see if I remember by grade school geometry (maybe!). Suppose we have two rectangle shaped blades for the sake of simplicity rather than like a drop point or something else so that the distance from edge to spine is uniform across the blade. Knife 1 is full flat ground 1/8" at the spine and 1" tall. Knife 2 also is full flat ground but is 1/4" at the spine and 2" tall. Would you call the first one "slicer" and second thicker and better for harder tasks because of edge geometry, concluding based on spine thickness alone? In fact they're the exact same thickness from the edge to up an inch high up (where knife 1 ends). One is not thicker at the edge than the other.

Okay so I answered myself.

Turn out the grinding take out so much weight that it enable a blade to be almost the same height, making it stronger in the end. By exemple;

The first one is 1/8" thick, 3" wide and grinded to 1". "Flat stock strenght" = 0,1875

The second is 1/4" thick, 2,25" wide and grinded to 2". "Flat stock strenght" = 0,2109

Same angle, same weight, the second end up being 12,5% stronger and thus lasting a lot longer for the same beating.

That was specifically my question, but thank you all for the precision around the subject.

 

[shane45-1911]

Turn out the grinding take out so much weight that it enable a blade to be almost the same height, making it stronger in the end. By exemple;

The first one is 1/8" thick, 3" wide and grinded to 1". "Flat stock strenght" = 0,1875

The second is 1/4" thick, 2,25" wide and grinded to 2". "Flat stock strenght" = 0,2109

Same angle, same weight, the second end up being 12,5% stronger and thus lasting a lot longer for the same beating.

That was specifically my question, but thank you all for the precision around the subject.

What???

This is how are you defining "stronger" and edge retention?

As I keep trying to tell you, the "strength" of a blade is the sum of MANY things, and certainly not the weird formula you indicated above . Steel type + quality heat treat + edge geometry to suit the task at hand = "strength".

 

[WeekSecret]

What???

This is how are you defining "stronger" and edge retention?

Yes it is a part of "stronger". It's called "section modulus".

No, it has nothing to do with edge retention, I was just asking if with the same angle, a thicker blade would have a better edge retention or not.

As I keep trying to tell you, the "strength" of a blade is the sum of MANY things, and certainly not the weird formula you indicated above . Steel type + quality heat treat + edge geometry to suit the task at hand = "strength".

As I mentioned above, it's to weight the pro and cons of each knife. Like to compare if a 0,22" crk pacific in s35vn and a 0,1875" spartan horkos in s45vn

I also know the edge geometry make a difference, hollow<flat<convex<scandi. It was never directly about the edge strenght and retention, it was about the overall strenght before the blade snap in half. I could have been clearer on that I admit.

As for the weird formula, it's enginering. It's probably not the good one, but it's close.

 

[Jsega51]

it has nothing to do with edge retention, I was just asking if with the same angle, a thicker blade would have a better edge retention or not.

Now this is a confusing statement lol

 

[shane45-1911]

I'm out.

 

[toker]

I think you're putting much too much theory into this. Buy a decent knife and put it through some testing. My guess is that a knife from any reputable manufacturer will not fail it's intended purposes.

 

[WeekSecret]

Now this is a confusing statement lol

English is not my first language, sorry if make confusion

Let say there is two flat grinded blade,

First one is 1" wide 0,125" thick

Second is 2" wide 0,25" thick

They got the same angle of grinding no? But would one have a better edge strengh and retention? I assume no?

 

[Bob Denman]

We may be debating "How many Angels can dance on the head of pin?" here.
There's no doubt that even the worst blade steel and design; can easily beat scratching away at something with your fingernails...
All 14,945 different types of steel (my useless number), have different characteristics. Choose your steel, and then you can figure out what you want to do with it; in order to have the stiffness/toughness/blade retention, and rust resistance that makes you happy.

 

[singularity35]

What about two blade with the same edge angle, making them with the "same" sharpness, one thicker and the other wider. Would they have the same edge retention?

As mentioned in a previous post, there are too many factors to conclude. I'll just say this, all other things being equal(steel, heat treat, etc.) the best cutter will be the one that's the thinnest behind the edge. I will also qualify that, that's only as long as the edge is not too thin. For example cutting wood with a straight razor. As for best edge retention, that would depend on the material being cut.

 

[Cobalt]

English is not my first language, sorry if make confusion

Let say there is two flat grinded blade,

First one is 1" wide 0,125" thick

Second is 2" wide 0,25" thick

They got the same angle of grinding no? But would one have a better edge strengh and retention? I assume no?

There is no difference in edge strength in your example if they both have the same edge grind. The difference will only be in lateral strength and stiffness. The wider/thicker blade will resist bending forces much more.

 

[Natlek]

You can see the width of the blade and make a fairly accurate estimate. Small errors in the estimate do not make a large difference in performance of the blade.
But the thickness is more difficult to estimate, and a small error in your guess can make a big difference.
So most sites will tell you the blade thickness, but just show you the blade width.

In reality it should look like this ........
What you look on first picture is one inch wide blade , looks like normal knife .................

then you see spine ....................................7mm

end edge side ...
WTF is this ?? Chisel ??

 

[Bob Denman]

What is that?
It's to carry just about like a splitting wedge in your pocket...