November 2025 - Magazine - Page 10
Mi n i str i es
OUT of TIME
Janka wood hardness scale
The Janka hardness scale measures the resistance of wood to denting and wear, providing
a standardized way to compare the hardness of different wood species.
Overview of the Janka Hardness Test
The Janka hardness test was developed by Austrian researcher Gabriel Janka in the early
20th century. It measures the force required to embed a 0.444-inch (11.28 mm) diameter
steel ball halfway into a piece of wood. The results are typically expressed in pounds-force
(lbf) in the United States, but can also be represented in kilograms-force (kgf) or newtons
(N) in other regions.
Purpose and Applications
The primary purpose of the Janka hardness scale is to determine the durability and
suitability of various wood species for applications such as flooring, furniture, and cabinetry.
A higher Janka rating indicates a harder wood that is more resistant to dents and wear. For
example, hickory has a Janka rating of 1820, while balsa, known for being very soft, has a
low rating.
Importance of the Janka Scale
Comparative Analysis: The Janka hardness scale allows for easy comparison between
different wood species, helping consumers and professionals select the right type of wood
for their projects.
Durability Assessment: It provides insights into how well a wood species will hold up under
normal use, making it a critical factor in flooring and furniture selection. In summary, the
Janka hardness scale is an essential tool in woodworking and construction, providing
valuable information about the hardness and durability of wood species, which aids in
making informed material choices.
