sometimes, wood can be downright confusing. while species are very generally grouped into hardwoods and softwoods, some hardwoods, like american black walnut, for example, are surprisingly vulnerable. to put it in the same category as a species known to be especially hard, like hickory or ash, seems wrong somehow. and what about maple, which is both hard and soft, depending on where it was sourced? oak is not simply oak, you have red and white, among others, and each has it’s own strengths.
to help mitigate some of these differences, a test was created to allow all materials to be rated on a scale for hardness. it is an essential tool if durability is a prevailing factor in material selection.
the janka scale was created specifically as a reference for evaluating a species’ individual resistance to focused pressure. the photo shows a ball bearing being applied under pressure to the wood. each species’ resistance to pressure determines it’s rating. simple, but an effective way to evaluate all species on a level scale.
just about any species used for woodworking, be it wide plank flooring, cabinetry, mouldings, or trim, has been tested and assigned a rating. most of the exotics from other countries are included as well, and the scale provides terrific insight for anyone who might have questions about a material’s durability. just click on the scale for an up-close look at them.