Australian Hardwood Janka Rating

The janka rating is a measure of the wood to resist indentation.

Australian hardwood janka rating.

The janka hardness test from the austrian born emigrant gabriel janka 1864 1932 measures the resistance of a sample of wood to denting and wear. The janka hardness test is the industry standard for determining the ability of a particular timber species to withstand denting and wear. In general terms a medium density timber will have a janka rating of 4 to 8 whilst a high density timber achieves a rating of 8. It measures the force required to embed an 11 28 millimetres 0 444 in diameter steel ball halfway into a sample of wood.

It has a uniform fine texture and a mostly straight grain that may occasionally interlock. This test measures the force required to embed an 11 28mm 0 444 in steel ball to half its depth into wood. Under the janka hardness rating simply the higher the number the harder the wood. The janka hardness test is the hardness level given to each species.

Australian blackwood is typically medium golden or reddish brown. The force used is then measured in kn kilonewton as the janka rating. What is janka rating. These ratings were determined using the janka hardness test which measures the side hardness measure of the force required to embed a 444 inch steel ball to half its diameter into the wood.

It is one of the best measures of the ability of a wood species to withstand denting and wear. The higher the janka rating the harder the timber species. Australian blackwood one of the most popular types of acacia wood flooring has a janka hardness rating of 1160 and a low volumetric shrinkage rate of only 11 9 percent. 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 depending on the room where the flooring will be installed a certain level of hardness may make it a more desirable choice.

Why is it used. 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 higher the janka rating number the greater the hardness. The janka hardness scale determines the hardness of a particular type of wood over another.

Woods with a higher rating are harder than woods with a lower rating. Technically the test involves pushing an 11 18mm diameter steel ball into wood fibre until it reaches half of the diameter of the ball. Hardness rating the hardness of a timber is measured by the janka hardness test. Hardness is expressed in kilo newtons.

This is done by testing the floor s resistance by measuring how much pressure is needed to embed an 11 28 millimetre ballbearing halfway into the boards surface. Even though a janka rating of 8 is considered hard many australian timber species achieve ratings of 12 and above.