How Can the Janka Test Help Me Select Which Species of Wood I Should Use?

Posted on December 01/2017
Hardness Test

We are often asked many questions such as: “There will be a lot of traffic on my stairs and I am afraid of scratches or dents. How can I determine which species of wood should I use?”. The answer is the Janka Test!
When determining the species of wood to use for your stairs, another consideration besides colors, grain, style is the hardness. Therefore we would refer you to the Janka test. The Janka test measures the force required to embed an 11.28 millimeter (0.444 inch) steel ball into wood to half its diameter. The Janka test measures the force required to embed an 11.28 millimeter (0.444 inch) steel ball into wood to half its diameter. This method was chosen so that the result would leave an indentation 100 square millimeters in size. It is one of the best measures of the ability of a wood species to withstand denting and wear. It is also a good indicator of how hard a species is to saw or nail.

The hardness of wood usually varies with the direction of the wood grain. If testing is done on the surface of a plank, perpendicular to the grain, the test is said to be of “side hardness.” Testing the cut surface of a stump would be called a test of “end hardness.”

Wood Species 

Janka Hardness                                  
Ipe / Brazilian Walnut / Lapacho                3684                                                                     
Cumaru / Brazilian Teak 3540 
Ebony 3220 
Brazilian Redwood / Paraju 3190 
Red Mahogany, Turpentine 2697 
Brazilian Cherry / Jatoba 2350 
Mesquite 2345 
Santos Mahogany, Bocote, Cabreuva 2200 
Purpleheart 1860 
Rosewood 1780 
African Padauk 1725 
Blackwood 1720 
Kempas 1710 
Zebrawood 1575 
Hard Maple / Sugar Maple 1450 
White Oak 1360 
Ash (White) 1320 
American Beech 1300 
Red Oak (Northern) 1290 
Yellow Birch 1260 
Brazilian Eucalyptus / Rose Gum 1125 
Black Walnut 1010 
Teak 1000 
Black Cherry, Imbuia 950 
Cedar 900 
Southern Yellow Pine (Longleaf) 870 
Douglas Fir 660 
Chestnut 540 
White Pine 420 

*References: The Janka Hardness Test