Southern Yellow Pine was shipped extensively to the north during the late 1700's and 1800's. It was used in many applications and was the flooring of choice in part due to its hardness and durability. In test results from Wood Handbook: Wood as an Engineering Material, hardness is measured by the load required to embed a 0.444 inch ball to one half its diameter in the known wood. This test (know as the JANKA test) is one of the best measures to determine the ability of wood species to withstand denting and wear. Results are as follows: Eastern White Pine - 290 Southern Yellow Pine - 690 to 870 Heart Pine - 1225 Red Oak - 1290 Southern Yellow Pine is two to three times as hard as Eastern White Pine and similar hardness exists between Heart Pine and Red Oak.