We are reader-supported. When you buy through links on our site, we may earn a commission. Learn more about our review process.

Nerdy Science in the Kitchen

How to Sharpen a Serrated Knife



It sits alone in the knife block, waiting for a job and then, whenever it is used for a big job, it is put away and forgotten. Yeah, I’m talking about the serrated knife. And they are great because they stay sharp for so long – due to their super smart serrated design.

Usually people think of a bread knife when they think of a serrated knife. But there are a few others, like the serrated utility knife.

And sharpening – when was the last time that you remember sharpening your serrated knife?

The serrated knife can be used for slicing type cuts, especially through tough or hard surfaces, since the serrations tend to grab and hold the tough surfaces.

Serrated Knives Still Work Great When Dull

The serrated knife is the only knife in the kitchen which will still perform when dull – a function of the blade arrangement. But, this ability is also the knife’s downside – since it never seems to get dull, it is often overlooked for sharpening.

The high points of the serrations touch the material first, giving those points higher pressure per area

The serrated edge gets its slicing ability from a number of factors. The high points of the serrations touch the material first, giving those points higher pressure per area than if the same pressure was applied to a plain blade. This allows the serration to puncture more easily.

sharpen a serrated knife

Additionally, serrations are typically chisel-ground into the blade, meaning they are thinner (and thus cut better) than the comparable plain blade. Chisel-ground just means that one side of the blade is sharpened to an angle, like 25º and the other is flat. (Read more about knife sharpening angles.)

Thus, serrated knives can be purposed for tasks other than bread – tough-skinned fruit such as melon and other whole citrus fruits, moist, soft cakes, and even tomatoes!

Tomatoes are best sliced with a serrated knife because a smooth bladed chef’s knife (the one that is never sharp enough) will succeed in only smashing the soft-skinned tomato meanwhile the serrated knife blade will slice through it like butter.

When the time comes for sharpening, the serrated knife requires a special sharpener. The serrated knife sharpener sharpens each serration separately.

OK – If you want to save time any of the electric knife sharpeners on this page will do the job on Stage 3.

Here’s how you sharpen a serrated knife:

• Choose a serrated knife sharpener with a grit size applicable to the job. This can be extra fine, fine, medium, coarse, or ceramic. The fine grit will provide a good cutting edge and will sharpen at a good rate, for most knives. The coarse grit is optional for a faster sharpening rate on very dull serrated knives. The extra-fine and ceramic grits will provide a polished edge.

We recommend using the coarse first, then the medium, and last the fine sharpener for a typical serrated knife.

• Next, match the cone diameter of the sharpener to the size of the gullet (the serration). The sharpener is wide at the base and tapers as it goes off to match the serrations.

• Using short, light, back and forth strokes, sharpen the beveled edge of each individual serration. After a few strokes, feel for a burr on the backside of the knife. Once you can feel the burr, move on to the next serration.

* Note: The key to getting your knife sharp, besides finding the proper angle, is ‘drawing a burr’ from each side of the knife. A burr is formed during the knife sharpening process as metal is drawn up and up over the edge of the tip of the knife. It can also be felt on the opposite side that you are sharpening on by running your thumb, carefully, up and across the edge.

The burr is important because it shows you are making progress and that you are sharpening in the correct location. It also shows that you are actually moving old and fatigued steel from the knife.

• Once all the serrations are sharpened, flip the knife over and lightly grind the burr off with a smooth, light flat stroke.

I personally use a Gatco Sharpening kit to sharpen my serrated knives.

Your knife should now be properly sharpened and ready to cut many more items now than just bread!

Check out this Youtube video: