Petty Knives versus Utility Knives: What’s the Difference?

The petty knife is essentially the Japanese version of the utility knife. As Donald explains in his book, the petty knife first arose during the Meiji era (late 19th century), when Western cuisine and cutlery were introduced to Japan. While the Japanese already had their own existing knife styles, they developed the gyuto (Japanese-style chef’s knife) and petty knife in response to the chef’s knife and utility knife they saw in Western-led kitchens. (The word “petty,” according to Donald, is likely derived from the French word “petit,” meaning “little,” a nod to the fact that these knives were considerably smaller than the average chef’s knife.) Following Japanese conventions, the petty knife had a blade that was thinner and harder than the Western knives; the blade itself had a more “triangular” geometry, with a straight, not curved, edge that enabled the sort of up-and-down cutting many Japanese cooks prefer. And the blades themselves were often hand-finished to ensure the keenest edge.

Today, however, distinctions between the two types of knives have become somewhat blurred, at least if the models we tested are any indication. Petty knives have changed very little. They’re still the exclusive province of Japanese knife manufacturers; if the model has “petty knife” in the name, it’s almost certainly Japanese. And they’re still made from thin, very hard steels (the models in our lineup had Rockwell ratings—a standard for measuring metal hardness—from 58 to 64 HRC) forming straight-edged, triangular blades. 

It gets more complicated with utility knives. You can find utility knives made by European, American, and Japanese companies. Utility knives made by European and American companies still bear some resemblance to the traditional models. The Western utility knives in our lineup were made from softer metals (from 55 to 58 HRC), and three of the four had curved edges. One of the Western utility knives looks more like the earlier, traditional models; its blade is narrow from tip to heel. (We actually didn’t like this model very much, as we no longer use these knives to perform the kinds of tasks for which they were originally intended.) But the others look more like mini chef’s knives with deeper bellies. And all the Western utility knives have gotten thinner and more agile, with smaller edge angles than before—characteristics that actually make them more similar to the Japanese knives that cooks have increasingly come to appreciate. They aren’t exactly the utility knives of yesteryear. 

The Japanese “utility” knives we tested complicate the picture further. One looks just like a traditional Western utility knife, long and narrow. The other is basically a petty knife, despite its name: straight edge; triangular geometry; thin, hard metal.

So are there meaningful differences between the two types of knives? Yes, though those differences have become far less clear-cut over the years. Our advice? Buy by function, not by name.