Ever make cookies? Ever wonder why there are so many different recipes? Ever get the ingredients just a bit wrong and wind up with a totally different cookie?
If you have, you’ve got an inkling of what it’s like to make a knife blade. It’s an intricate process that involves various techniques including cutting, forging, heating, cooling, mixing, grinding, buffing and crushing!
Blade Hardness
The most important thing to know about a kitchen blade is its “hardness”. Hardness in kitchen knives is a good thing — the harder a blade, the sharper an edge it can tolerate. Just like with cookies, though, too much of a good thing can be overkill. Blades that are too hard can be brittle and prone to breaking or even shattering. Ceramic blades have become less popular in recent years due to their brittleness. Drop a ceramic knife on the floor and you’re out your $300.
Hardness is measured on the Rockwell Hardness Scale (HRC). Measurements are typically in the 55-60 range. Some of the sharpest Japanese knives are hardened to an HRC of more than 60, while Wusthof and Henckels knives are typically closer to 55. It might not sound like much, but a few points on the Rockwell scale can make a big difference.
Blade hardness is probably the biggest difference between Japanese and German knives. Japanese knives are hard, sharp surgical instruments. They are razor-sharp but require careful handling. German knives are duller but require less maintenance. See The Rise and Fall of The Great Knife-Makers for more on this distinction.