When determining which type of lumber to use, hardness is often an important factor. Although not every individual needs a hard lumber for their project, the hardness of a wood helps to determine how durable and reliable the lumber is. So before you purchase lumber for your next project, the lumber experts at McIlvain Company want to make sure you understand the Janka Hardness Scale, a measure of wood’s hardness that is utilized by most reputable lumber industry companies.
Since its founding in 1922, the Janka Hardness Scale has been used by many craftsmen and lumber experts. The Janka Hardness Scale is the industry standard for gauging the ability of various types of wood to tolerate normal wear and tear. It shows the lumber’s ability to withstand dents and impact, factors that are important for every craftsman and expert builder, and the Janka Hardness Scale also indicates whether a wood can withstand a saw or nail. The most common use of the Janka Hardness Scale is to determine if a species of lumber is suitable to use for flooring.
To measure the hardness of lumber, the Janka Hardness Scale uses an 11.28 millimeter steel ball as its guide. It measures the force required to embed half of the ball’s diameter into the wood. The steel ball is approximately half an inch in diameter; therefore, the Janka Hardness Scale shows the force it takes to push the steel ball approximately a quarter of an inch deep. While the Janka scale is not considered an absolute, it is a guideline to show which lumbers are harder than others.
Like various areas of the world measure length in centimeters or inches, different regions measure the Janka Hardness Scale differently. In the United States, the measurement is in pounds-force. In Sweden and much of Europe, they measure the Janka Hardness Scale in kilograms- force. In Australia, it is measured in newtons or kilonewtons. Since there is no specific unit of measurement, every country converts their findings to meet the Janka Hardness Scale in pounds per force.
The direction of the grain determines the hardness of the lumber. When the Janka Hardness Scale test is done on the surface of the plank with the force exerted perpendicular to the grain, the “side hardness” is determined. End testing is sometimes done by testing the side end or stump of the piece of lumber. The location of the testing will vary the results of the test, and all results are taken into account.
There are hundreds of types of lumber whose hardness has been plotted on the Janka scale. From Australian Buloke lumber with a Janka Hardness of 5060 pounds- force to Cupio lumber with a Janka Hardness of 22 pounds- force, lumbers’ hardness can vary greatly. Red Oak, which has a Janka rating of 1290, is the common industry standard for comparing the relative hardness of different lumbers.
With more than 200 years of experience providing the best quality lumber to all customers, McIlvain Company has an extensive background and knowledge of lumber. The lumber experts at J. Gibson McIlvain are fully equipped to help customers decide on the best type of lumber for their projects, using the lumber’s Janka hardness rating and many other factors. For more information on how McIlvain can help you, visit their website today.
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