Understanding Blade Edging Structure

Let’s talk about blade sharpening—putting an edge on it! I’ve written about it on the blog before, but sharpening isn’t just about giving the blade an edge; it’s about creating the very structure of the blade itself. In other words, it transforms the cutting performance and the feeling of how it slices completely.

It’s not just about sharpening the blade’s edge; it’s about thinking about how to let the sliced ingredients release! It might sound complicated, but it essentially comes down to creating what we call a Hamaguri edge! Hamaguri might have been mentioned before, so let’s touch on something different.

When we talk about double-edged and single-edged knives, the expressions ‘cuts well’ and ‘sharp’ suit single-edged knives! At least in my experience, single-edged knives seem to cut better. I’ve heard that you can achieve cutting performance just as good as a single-edged knife with a perfectly honed double-edged knife, but… making a flawless double-edged blade is really challenging!

<<So, recent experiments?? Challenges?? Trial and error>>

Most household knives are of the double-edged style. I decided to infuse the essence of a single-edged knife into these knives to make them sharp yet maintain their double-edged nature. To infuse single-edged essence into these knives, it’s best to convert them into single-edged knives. However, some knives like the 3-layered ones will turn into soft iron if converted into single-edged knives and lose their cutting ability! Moreover, when they become single-edged, they become harder to cut straight with, the blade becomes weaker, and you’ll need separate knives for the left and right hands!!!

‘In that case, why not just buy single-edged knives from the start!’ you might say.

This time, to see the difference, I sharpened double-edged knives as much as possible to make them cut well up to what I thought was their limit! If I sharpened them even more, they would cut even better, but the blades would become too thin and weak… in other words, fragile!!!

Next, I attempted to infuse the essence of a single-edged knife into these double-edged knives! The way to infuse this essence is simply by creating a single edge with an Itohiki blade. It’s like using a ‘kite string hiki’ method—about 5.5 on the front and 4.5 on the back. That’s the feeling!

I finished only the edge like this, leaving the rest of the blade with the structure of a double-edged knife. This changes the way the blade engages with the cut entirely!!!

Try it with the double-edged cultural knives you have at home…

Note: Please do this with Japanese-made cultural knives!!

• 2007-12-05(15:13)