The Janka Hardness Scale. Heard of it? Possibly! Know how it works? Well… maybe. Today, we're delving into the world of wood density and durability, and our guide is none other than the Janka Hardness Scale. This scale is key to deciphering the resilience of different wood species, and will help you make more informed decisions for your small projects and furniture. So, before you curse that heavy butter knife for slipping off the plate and dinging your pine dining table, let's unravel the mysteries of wood density, and even a little science, behind the Janka Hardness Scale!
Wood Hardness: How is it Measured?
In 1906 an Austrian wood researcher, Gabriel Janka, invented a test that determines the density of a wood species by measuring the force required to press an 11.28mm (just under a ½ inch) steel ball halfway into the wood. The resulting value, expressed in pounds-force (lbf), gives a measure of the wood species' resistance to denting. These measurements have been compiled into what we know today as the Janka Hardness Scale, giving insight into what wood may be right for your next project. And this shockingly simple test, rules our craft!
Hardwood Heavyweights: Defying the Odds
At the top of the Janka Hardness Scale, we find the hardwood heavyweights that can take a lickin’ and keep on tickin’. Ipe and Cumaru are near the top with impressive ratings of 3,680 lbf and 3540 lbf, respectively. (The Janka scale tops out at 4,000 lbf.) These robust woods are popular for outdoor decking and high-traffic areas where durability is paramount. They are also favored for tool handles and even mallets because they can endure constant use and potential abuse, with little need for repairs.
Pro tip: At a Janka rating of 1,800, Hickory is the densest domestic hardwood available on the commercial market. Sure, it’s Janka rating appears meek compared to the exotics listed above, but, on the whole, Hickory is stronger than White Oak or Hard Maple. Its density makes it notably more difficult to work with than its domestic counterparts, and requires razor-sharp tools to prevent tear out. (But the beauty of hickory is well worth the effort!)
Middleweights: A Balance of Strength and Elegance
These hardwood middleweights hit the sweet spot with the just the right amounts of hardness, workability, and beauty. Woods like White Oak (1,360), Ash (1,320), Hard Maple (1,450) and Black Walnut (1,010) fall into the middleweight category. While not as hard as the heavyweights listed above, these species strike a balance between durability and aesthetic appeal. They are often chosen for furniture and decorative elements that will be in daily use, where both toughness and visual appeal are essential. Many of these woods are noticeably easier to work with than the heavyweights and less likely to kill your blades! BTW, Soft Maple (999) is also a hardwood and is only considered, “soft” in relation to Hard Maple.
Lightweights: Tough Enough and Still Beautiful
Once you fall below 1,000 on the Janka scale, you enter a new group. While still technically hardwoods, the density of these woods is a little soft for daily life and better serve as accent pieces. These species include Poplar (540), Alder (590), Black Cherry (950), African Mahogany/Khaya (845), Sycamore (770), and Basswood (410).
Basswood is preferred by carvers due to its fine grain structure and almost white color. While, due to it's density, cost and availability, Poplar is a woodworking powerhouse for everything from kitchen cabinets to molding to furniture. It has the grit to get the job done, but can be prone to dings. So, as an accent tabletop or bedroom dresser top it would serve well, but less so as a dining tabletop. And yes, cherry is a beautiful fine-grain wood, but at 950 on the Janka scale, its gonna’ show some scars from family life…
Softwood Versatility: Easy to Dent, Easy to Love
Softwoods like Fir (660), Western Red Cedar (320) and Cypress (510) often have lower Janka ratings compared to hardwoods, making them more susceptible to denting and wear. However, their versatility and lighter weight make them ideal for projects where a softer touch is acceptable. Softwoods are commonly used for projects such as shelves, decorative pieces, or accent walls for a home! You can use them for furniture and tables, just be ready for the inevitable dings. Yellow pine is also a softwood, but its Janka rating hits about 950, so you get a bit more durability for your money.
Conclusion: Decoding Wood Durability
Armed with the knowledge of the Janka Hardness Scale, you're now equipped to navigate the diverse world of wood with confidence. Still have questions? Feel free to reach out to us here Hardwood Lumber and Millwork! Whether you're embarking on your first DIY project or a contractor looking for a custom piece, we would love to work with you to bring your vision to life! After all, a well-informed choice today ensures a lasting legacy for your wooden creations for years to come.