Jenka Scale of Hardness

The Janka rating is determined by the number of pounds of pressure required, to press a stainless steel ball, with a diameter of .444inches, halfway into the side of a board. Do not take hardness to mean it’s the best one to select.

Material

Relative Hardness

Douglas Fir

660

Yellow Pine

690

Southern Yellow Longleaf Pine

870

American Cherry

950

Black Walnut

1010

Heart Pine

1225

Birch

1260

Red Oak

1290

Beech

1300

Ash

1320

White Oak

1360

Maple

1450

Bamboo (average)

1820 (varies)

Hickory/Pecan

1820

Purple Heart

1860

Santos Mahogany

2200

Brazilian Cherry

2350