What is the Janka Hardness Test?
The Janka hardness test measures the resistance of wood to denting and wear. Testing is done on samples, not on actual flooring.
It measures the force required to embed an 0.444 in steel ball into wood to half the ball's diameter.This method leaves an indentation.
In the United States, the measurement is in pounds-force (lbf) or simply treated as units (ex. "660 Janka").
Details please refer to diagram below.
A common use of Janka hardness ratings is to determine whether a species is suitable
for use as flooring. 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