Completing the Janka hardness test creates a circular indention with an area of 100 square millimeters. This means that the testing is done on the surface of a plank, with the force exerted perpendicular to the grain.

The hardness of wood usually varies with the direction of the grain, so if testing is done on the surface of a plank, with the force exerted perpendicular to the grain, the test is said to be of “side hardness.” Side hardness of a block of wood measured in the direction of the tree’s center, and on a tangent to the tree’s rings, are typically very similar.

End testing is also sometimes done, which is completed by testing the cut surface of a stump. The side hardness of teak, for example, is in the range 3730 to 4800 newtons, while the end hardness is in the range 4150 to 4500 newtons. Historically, the most common use of the Janka hardness ratings is to determine whether a species is suitable for use as flooring
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While there are many factors to consider when choosing your hardwood flooring, durability of your hardwood is definitely one factor to think about. The harder a wood, the more durable and strong it tends to be.

Hardwood flooring can last for decades. It insulates well and improves the frame strength of a house. It helps a home sell faster and can add a spike to its selling price. Hardwood lumber, floors, staircases, and moldings create rich natural colors with handcrafted quality. Hardwood enhances any environment in which it’s introduced. Some quick reasons why you should choose hardwood: Natural, warm and authentic color, simple, yet decorative for any room in the house, rugged yet charming, durable yet easy to care for, beauty that’s hard to tire of and has the potential to last the lifetime of the home. Hardwood introduces a definite stature and an undeniable charm to any room and becomes more valuable as time goes by.

With hardwood, you have three options to maintain its quality, character, and integrity: Firstly, you can lightly screen and re-coat with urethane to bring back the original luster, secondly, you can completely sand and refinish the surface to make the wood look like new, and thirdly, a urethane-protected hardwood surface provides so much durability you may never need to choose either of the above two options.

Knowing the Janka hardness scale of your chosen species will assist you in knowing how to care for your wood and to estimate what type of future care will be required.