Understanding Wood Hardness and the Janka Scale: What It Means for Your Projects

Woodworkers often hear the term “Janka hardness” and wonder whether it really matters. In short—yes, but not in the way many people think. The Janka scale measures how much force it takes to embed a steel ball halfway into a piece of wood. It’s not describing how hard a wood is to cut; it’s describing how resistant it is to denting and wear.

For something like a cutting board, you want a species that’s hard enough to handle daily use but not so hard that it dulls knives instantly. That’s why Walnut and Maple remain the classics—they strike a balanced place on the scale. At the higher end, woods like Bubinga or Purpleheart are extremely dense and durable, making them excellent for knife scales or turned projects where crisp details are important.

On the softer side, woods like Cherry or Poplar are easier to work and sand. They’re not ideal for heavy-duty surfaces but great for decorative pieces or accents. Hardness also impacts how much tear-out you’ll experience. Dense woods generally turn cleaner, while open-grained species sometimes require sharper tools or slower cuts.

Understanding the Janka scale is less about memorizing numbers and more about matching the characteristics to your project. A pen made from Osage Orange will feel very different from one made from Cedar. Knowing why helps you make more confident material choices and achieve the results you’re aiming for.