The Janka Hardness test is used primarily to determine the hardness of a wood species, and whether it is suitable to use as hardwood flooring. To conduct this test, a steel ball that is 11.28 mm is forced into a sample piece of wood until half of the ball's diameter is embeded. As shown here:
The force that was used to embeded the steel ball is then measured. Below is a current list of wood species sold by Johnson Hardwood. You may also click on the box below to be directed to a printable PDF version.