The simplest and most common way people define if a wood is “strong” is usually hardness. I’ve written about wood hardness before—as a matter of fact, I even have an entire poster ranking the hardness of all sorts of woods worldwide. But this is a very one-dimensional way of approaching the question.
Here are some questions to consider:
- What if we want to make a ramp where heavy machinery will be wheeled across the wood? We don’t want the planks to break.
- How about a bookshelf, where a continuous load will be applied? We don’t want the wood to bow or sag.
- What if we are making chair legs which will need to support a lot of weight parallel to the grain? We don’t want the wood to be crushed and give out.
All of the above scenarios have nothing to do with wood hardness. They are real-world examples that parallel totally separate wood tests (modulus of rupture, modulus of elasticity, and crushing strength, respectively).
