Please define - behind the edge

wardcleaver

wardcleaver

Joined
Apr 17, 2017
Messages
290
Where exactly do you measure to find the behind the edge dimension?

I'm guessing its where the "sharpening bevel" meets the "main blade grind"
I'm not real sure of my terminology, but I think you will know what I'll trying
to describe.

TIA
 
Yes some times after reprofiling, the "behind the edge" is quite a ways further up the blade for instance some stock edge grinds from the factory can be a half millimeter from the edge and that is the behind the edge area or after reprofiling I can be three millimeters from the edge to measure the behind the edge.

It's a general thing. Sort of effective cutting performance but lots of beefiness for . . . I don't know what . . . starts at less than 30 thousandths behind the edge. ( I don't know why we mix inches and metric; mostly I use metric but I think we all under stand the behind the edge thickness easier if we talk in thousandths partly because that is what is used in the Ankerson Rope Cutting Tests.)

Often halfway decent factory edges are around 18 thou to 22 thou.

You want world class performance ? You want something that will make Ankerson glance your way and consider testing the edge as a top performer ? Then you need to be around 8 thou or down to 4 or 6 thou.

Don't worry about it much just have fun.
The thinner the better I say ;) :thumbsup:
 
Yep. I've got most of my kitchen knives around .010" behind the bevel. SO much better than factory. And "behind the bevel" has always made more sense to me than "behind the edge."
 
BTE- Behind the edge.

Measure at the shoulder of the bevel.

You also have to give an estimate of what the bevel angle is for the BTE to really make sense.

15dps and 15bte is not the same as 20dps and 15bte.

If you drop the angles on the 20dps to 15dps it will be closer to 20bte when measured again at the shoulder.

So when giving measurements it's best to give the degrees per side and the behind the edge thickness so it all makes sense.

Use calipers to take a measurement on BTE
An angle cube can help estimate DPS
 
wardcleaver said:
Where exactly do you measure to find the behind the edge dimension?

I'm guessing its where the "sharpening bevel" meets the "main blade grind"
I'm not real sure of my terminology, but I think you will know what I'll trying
to describe.

TIA
Click to expand...

Obviously DBH gave great input but as for the terms, the "main blade grind" is commonly known as the primary bevel and the "sharpening bevel" is generally considered the secondary bevel. :)
 
Eli Chaps Eli Chaps I see it both ways with regularity, unfortunately. Here are a few counterexamples to your assertion.

https://sharpeningmadeeasy.com/Juranitch1977Feb.htm
Fold in half again, and you have 22.5 degrees. Hold the blade at this angle or slightly less for your primary-edge face (right). Fold the paper again and you get 11 degrees. This is the angle you should use with the coarse hone for the secondary edge.
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Image13.gif


https://blog.poachedjobs.com/2017/08/30/how-to-sharpen-a-knife/
Let’s begin with the most important information: the primary edge on a blade is the sharp edge that can cut you. The primary edge initiates a cut. The secondary edge is the V-shape of the blade starting right behind the primary edge which dictates how easy or difficult it is to pass the blade through things. (Murray Carter)
Click to expand...

https://thekitchenprofessor.com/blog/a-guide-to-knife-edges
If you look closely at the blade of your kitchen knives, you should notice a part at the very edge that angles more steeply–this is the primary bevel. Most of the time people refer to the Edge Angle—see the image below.
Click to expand...

https://www.caseyspm.com/Knives.html
KnifeFigure-5.gif


https://kitchenknifeguru.com/knives/knife-edges-101/
The term bevel is commonly used for any surface on the blade that has been ground to form the edge. The primary bevel is the largest (and most visible) and can vary greatly in depth—from a 32nd of an inch to 3/8ths or larger. Go to the kitchen and look closely at the blade of your chef knife. You’ll notice near the edge of the blade there’s an area where it angles more steeply—that’s the primary bevel.
Click to expand...

https://www.edgeproinc.com/sharpening-tips.html
Instead, keep your primary bevel up at 19 degrees or higher and put on a second bevel between 10 and 15 degrees. You can make you primary bevel very small, like 25 or 30 thousandths wide. Now the knife will re-sharpen in seconds with only a very fine stone or even a tape.
Click to expand...

https://knifesharpeningbyhand.com/knife-sharpening-chicago/knife-sharpening-process/
The primary edge of a knife is, obviously, the point of first contact — the cutting edge. What’s not so obvious is how important the secondary edge is to effortless slicing.

The secondary edge is the second taper behind the primary edge. The edge geometry is the angle of the edge relative to the thickness of the secondary edge.
Click to expand...
 
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There are plenty of sources, probably more, stating the opposite. However there is enough disagreement and confusion that it seems like one either has to define the terms at the outset of every article or use different terms entirely, like blade grind, cutting bevel, relief bevel, etc.
 
Much Thanks to everybody who replied. I kinda thought I was on the right track,
but its nice to get a little clarification and some dimensions from the experts.
Now I just need some time to read, watch and digest all that good stuff.

Happy Sharpenin'!! :D
 
Mr.Wizard said:
There are plenty of sources, probably more, stating the opposite. However there is enough disagreement and confusion that it seems like one either has to define the terms at the outset of every article or use different terms entirely, like blade grind, cutting bevel, relief bevel, etc.
Click to expand...

In my understanding and research, the differences in terminology come from Japanese terms vs western terms. In America as knife makers we generally refer to the first bevel that we put on a blade as the primary grind, and the edge itself as the secondary grind ('bevel' can also be used in place of 'grind'). There's no right or wrong way to use terms, but it does cause confusion and must be clarified when discussing geometry. I have to do this a lot in my line of work lol
 
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