Behind the edge database!

[Cambertree]

Southfork:
0.023”/0.119”/0.119”
0.58mm/3.02mm/3.02mm

BTE/spine/stock

The spine has a distal taper so I put the same value as the stock thickness.

[Cambertree]

52100 CE Paramilitary 2:

0.022”/0.136”/0.145”
0.56mm/3.47mm/3.7mm

BTE/spine/stock

BTE measurement is averaged from 3 readings along the plain edge section.

[JustinB]

Native 5 LW Rex 45
.016 / 0.120 / 0.126

[Sharp Guy]

Native 5 LW Rex 45
.016 / 0.120 / 0.126

You must have one that's ground really thin. I just checked mine and got:

.022 / .120 / .125

[JustinB]

Native 5 LW Rex 45
.016 / 0.120 / 0.126

You must have one that's ground really thin. I just checked mine and got:

.022 / .120 / .125

Yeah, I was surprised at how thin it was. She's a good performer for sure

[zhyla]

We should organize this into a public Google spreadsheet.

I really wish thickness behind the edge was a spec that manufacturers published. I think we would see a trend toward thinner edges pretty quickly.

[The Meat man]

We should organize this into a public Google spreadsheet.

I really wish thickness behind the edge was a spec that manufacturers published. I think we would see a trend toward thinner edges pretty quickly.

Thing is, to get the whole story you also need to know the edge angle. 0.010" BTE might not perform any better than 0.030", if the edge angles are not the same.

[JustinB]

We should organize this into a public Google spreadsheet.

I really wish thickness behind the edge was a spec that manufacturers published. I think we would see a trend toward thinner edges pretty quickly.

Thing is, to get the whole story you also need to know the edge angle. 0.010" BTE might not perform any better than 0.030", if the edge angles are not the same.

That is true, a knife with a 50 degree bevel but is 0.010" behind the edge will not perform nearly as well as one that is at 15 degrees but 0.025" behind the edge. Behind the edge thickness is only one factor in slicing performance. Blade geometry, stock geometry, blade grind, blade steel, blade finish, edge finish, steel heat treat, etc all have parts to play in cutting performance and edge retention

[Evil D]

We should organize this into a public Google spreadsheet.

I really wish thickness behind the edge was a spec that manufacturers published. I think we would see a trend toward thinner edges pretty quickly.

Thing is, to get the whole story you also need to know the edge angle. 0.010" BTE might not perform any better than 0.030", if the edge angles are not the same.

It's really just a fun topic. I knew going into it that there were too many variables to really KNOW what to expect, but we can at least average the numbers and get a ball park.


If anyone wants to spreadsheet this and maintain it you can go for it, I don't mind one bit.

[The Meat man]

We should organize this into a public Google spreadsheet.

I really wish thickness behind the edge was a spec that manufacturers published. I think we would see a trend toward thinner edges pretty quickly.

Thing is, to get the whole story you also need to know the edge angle. 0.010" BTE might not perform any better than 0.030", if the edge angles are not the same.

It's really just a fun topic. I knew going into it that there were too many variables to really KNOW what to expect, but we can at least average the numbers and get a ball park.


If anyone wants to spreadsheet this and maintain it you can go for it, I don't mind one bit.

Oh for sure. This is a great thread and obviously the more information we have, the better.
It's just something I've been thinking about, as I become more aware of what actually improves cutting ability. BTE is hugely important but it's not everything: some knives I've owned have been really "thin" behind the edge until I put a 15 dps edge on them.
My K390 Police 4 is about 0.030" BTE but it's sharpened to about 10 dps, and I'd bet it would outperform a lot of knives with half the edge thickness.

[Evil D]

some knives I've owned have been really "thin" behind the edge until I put a 15 dps edge on them.

Exactly. Thin ground blade is only part of the equation, if the edge is ground at 90 degrees inclusive it's not going to cut very well at all. Then when you do thin out the bevel, your BTE number gets bigger despite the fact that the knife likely cuts far better now.

[Deadboxhero]

We should organize this into a public Google spreadsheet.

I really wish thickness behind the edge was a spec that manufacturers published. I think we would see a trend toward thinner edges pretty quickly.

Thing is, to get the whole story you also need to know the edge angle. 0.010" BTE might not perform any better than 0.030", if the edge angles are not the same.

It's really just a fun topic. I knew going into it that there were too many variables to really KNOW what to expect, but we can at least average the numbers and get a ball park.


If anyone wants to spreadsheet this and maintain it you can go for it, I don't mind one bit.

Oh for sure. This is a great thread and obviously the more information we have, the better.
It's just something I've been thinking about, as I become more aware of what actually improves cutting ability. BTE is hugely important but it's not everything: some knives I've owned have been really "thin" behind the edge until I put a 15 dps edge on them.
My K390 Police 4 is about 0.030" BTE but it's sharpened to about 10 dps, and I'd bet it would outperform a lot of knives with half the edge thickness.

Yes, DPS is important for understanding how thin the BTE is.

So, one can see that the edge bevel at the same angle DPS gets wider if the BTE is thicker.



Which means a low dps on a low bte will look like a mircobevel.

[Deadboxhero]

If the edge ain't bending, you pretending :D :p




Rex 121 at 70.5rc
0.007" BTE, 15° DPS

[The Meat man]

If the edge ain't bending, you pretending :D :p




Rex 121 at 70.5rc
0.007" BTE, 15° DPS

Good grief Shawn! Who needs kitchen knives? I think I could dice a tomato just showing it this picture. :p :D

That's incredible work. :cool:

[Deadboxhero]

Thanks, it was a True Laser. :)

If the edge ain't bending, you pretending :D :p




Rex 121 at 70.5rc
0.007" BTE, 15° DPS

Good grief Shawn! Who needs kitchen knives? I think I could dice a tomato just showing it this picture. :p :D

That's incredible work. :cool:

[Cambertree]

K390 Dragonfly 2:

0.016”/0.094”/0.094”

0.41mm/2.4mm/2.4mm

BTE/spine/stock

The thickest point of the swedge of the Dragonfly gives the same thickness as the bladestock, just in front of the ricasso. Obviously, it’s thinner at the actual spine - about 0.055”/1.4mm as far as I can make it.

Another interesting thing is the Dragonfly gets progressively thinner BTE to the tip, where most Spydies I’ve miked get a thou or two thicker.

I’m pretty happy with this grind, it’s going to be a wicked slicer! :cool: :spyder:

And it looks like the K390 is run pretty hard too, from the data starting to come into the HRc thread. :)

[Cambertree]

Proficient:

0.020”/0.133”/0.140”

0.51mm/3.37mm/3.55mm

Chinook 4:

0.032”/0.130”/0.137”

0.81mm/3.31mm/3.49mm

BTE/spine/stock

[elena86]

Did anyone measure their Watu ? Just curious ...

[Abyss_Fish]

Did anyone measure their Watu ? Just curious ...

I’ll second that request. My watu is my best slicer by far.

[Abyss_Fish]

Just got my hands on some calipers. My Watu is an even 0.010” along the entire edge. It’s absolutely the slicer we all thought it was. Although I could’ve told you that 2 months ago :D

- Comparatively, my Rhino varies between 0.010”-0.016” along the edge (mostly thickening near the tip but the grind in general seems to be a little wonky).
- My Native 5 salt clocks in at an even 0.019” all the way along the edge.
- My Waterway is 0.015” along most of the edge, but thickens up to 0.020” at the tip. Which on a fixie I honestly prefer.
- And I took my Spydiechef out of storage to confirm what I already thought. 0.020” along the belly and a mildly painful 0.027” at the tip. As I said in my 1 year review, this is no where near the kitchen knife standards, or even really spyderco knife standards.

And just for comparison on that spydiechef measurement, my work knife from Takamura cutlery is between 0.003”-0.005” behind the edge. And my Miyabi birchwood is 0.010” behind the edge. Those are both Gyutos’ (the Takamura is a tad longer) made of stainless cladded SG2/R2. The Takamura is 55 bucks less than the spydiechef, and the 5.3” petty from the same line is 110 bucks cheaper. Spyderco should probably grind the spydiechef thinner at its price point, just sayin...