# How to quantify knife-edge sharpness

• mooktank
In summary, the conversation discussed the design of a cutting blade and how to quantify sharpness. The speaker mentioned using a burr to test sharpness and using CPM-S90V steel for the blade. They also mentioned the importance of properly instructing the machine shop in creating the blade. The idea of using a burr to determine sharpness was also seen on a TV show about kitchen knives.
mooktank
I'm designing a cutting blade and I'm working on the drawing right now. I have the geometry and surface finish spec'd but I was wondering is there some way to quantify sharpness of an edge? Can I just say to grind the edge until a burr forms and knock the burr off?

I believe I've heard of this before. The best steel blades are melted and folded... melted and folded--- look at the samurai blade.

What you said sounds right, just make sure have some sort of edge to begin with. I think I the actually cut the burr off with another knife if I remember correctly.

Sharpness I don't think can be quantified. However, you might would want make a prototype and check how well it holds it's sharpness--- that is the true test.

violin_writer said:
Sharpness I don't think can be quantified. However, you might would want make a prototype and check how well it holds it's sharpness--- that is the true test.

We're making the blade from CPM-S90V, a particle metallurgy steel. It makes a very good blade and we've done some testing with a blade that's not as sharp as it could be.

I just want the machine shop to be able to make the part properly.

cool...

I think you just tell them to knock the burr off, because when a blade has a burr it's as sharp as it can get. At least that what I saw in "how it's made" or a show like it with kitchen knives.

## 1. What is knife-edge sharpness?

Knife-edge sharpness refers to the level of sharpness at the edge of a blade, typically measured by the angle of the cutting edge.

## 2. How is knife-edge sharpness measured?

Knife-edge sharpness can be measured using a variety of methods, including visual inspection, force required to cut through a material, or specialized equipment such as a sharpness tester or microscope.

## 3. What factors affect knife-edge sharpness?

Several factors can affect knife-edge sharpness, including the type of blade material, angle of the cutting edge, and the method used to sharpen the blade.

## 4. Can knife-edge sharpness be objectively quantified?

Yes, knife-edge sharpness can be objectively quantified using specialized equipment and measurement techniques. However, there can be variations in measurement depending on the method used.

## 5. How can knife-edge sharpness be improved?

To improve knife-edge sharpness, it is important to use the proper sharpening technique and tools for the specific type of blade. Regular maintenance and proper storage can also help to maintain sharpness over time.

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