Janka Rating Hardwood

The scale was invented in 1906 by gabriel janka an austrian wood researcher and standardized in 1927 by the american society for testing and materials astm.

Janka rating hardwood.

Hardwood flooring species are usually compared to red oak as the basis such as. To give some quantification to the issue of wood species hardness the lumber industry created the janka hardness scale a standard now widely accepted as the best means of ranking a wood s hardness. Forest service list the relative hardness for numerous wood species used in flooring. The janka scale is used to determine the relative hardness of particular domestic or exotic wood species.

The janka hardness test the janka test is a measure of the hardness of wood. Use this guide to understand precisely what each rating means for a better likelihood of choosing the right hardwood flooring. It is not productive to take issue with the exact number but rather understand the relative hardness of one wood to another. A janka rating is a hardness estimate given to wood.

No matter what species you re interested in chances are it has already undergone the janka hardness test. Woods with a higher rating are harder than woods with a lower rating. The janka hardness scale determines the hardness of a particular type of wood over another. In laymans terms it is a way to measure a woods resistance to denting.

The scale used in the table is pounds force. The janka test measures the amount of force needed to drive a 0 444 inch steel ball into wood to a depth equal to half its diameter. The janka rating scale was created to rank the various degrees of hardness throughout the different species of hardwoods. The higher the number the harder the wood.

For hardwood flooring the test usually requires a 2 6 sample with a thickness of at least 6 8mm and the most commonly used test is the astm d1037. The test measures the force required to push a steel ball with a diameter of 11 28 millimeters 0 444 inches into the wood to a depth of half the ball s diameter. A common use of janka hardness ratings is to determine whether a species is suitable for use as flooring. Similar to a laminate ac rating the hardwood floor hardness determines the durability of the species.

Brazilian cherry jatoba hardwood flooring is 224 times harder than a red oak floor. In hardwood flooring the score is used to determine the durability of hardwood species that it might be suitable for a home. As an example red oak hardwood has a janka rating of 1260 meaning it took 1260 pounds of force to embed the steel ball half way into the sample piece of red oak. The janka test measures the amount of force required to embed a 0 444 steel ball into the wood to half of its diameter.

The janka number is found by pushing a steel ball into a 2 x 2 x 6 wood plank.