Honing versus Sharpening

If you purchased your knives in a set, they likely came with a honing rod. Regular use of a honing rod will keep your knives sharp, but it won’t sharpen them. Confused? Read on…

Honing

Honing steel recap

Experienced cooks use a honing rod to hone their knives between sharpening. Honing doesn’t sharpen the knife, but when used properly, they will keep a knife sharp longer.

What’s the difference? Well, sharpening a knife involves removing metal from the cutting edge to form a sharp angle. During use, the leading edge of that sharp angle has a tendency to get bent over to one side, dulling the knife. Honing pushes that bent edge back into alignment, keeping the knife sharp.

Before and After Honing

Sharpening

Eventually, that edge isn’t just bent over, it’s gone. When metal is missing from the cutting edge, it is rounded over and the angle is lost. At that point, the knife needs to be sharpened by removing metal to reform an angle. No amount of honing will sharpen a truly dull knife.

Sharpening Geometry

The cutting edge of a knife can have different geometries depending on the equipment and technique used to sharpen. The most common are:

V or Flat grind

Each side of the blade is ground to the same angle
Most commonly achieved using a whet stone or belt sander on a platen

Convex

Each side of the blade is ground with a slightly convex
Most commonly achieved with a belt sander with some slack in the belt

Asymmetrical

A different angle is used on each side of the knife
Uncommon

Compound double bevel

Some blades have a “primary” angle and a “secondary” angle closer to the cutting edge
With these knives,

Hollow ground

Each side of the blade is ground with a convex curve
Most commonly achieved as a result of grinding with a wheel, which imparts the concave shape on the blade

Single bevel

One side of the knife is flat (or commonly with a slight hollow grind) and the other is angled
The angled edge will often have a primary and a secondary bevel
The most common geometry for scissors and certain Japanese knives, including sushi knives