The Janka hardness scale is a rating system used to determine the relative hardness of different wood species. The scale was invented by Gabriel Janka, an Austrian wood researcher, in 1906, and it measures the force required to embed an 11.28-millimeter-diameter steel ball halfway into a sample of wood. The test is conducted on wood that has been dried to a 12% moisture content, unless otherwise noted.
The Janka hardness scale ranges from 0 to over 4000 pounds-force (lbf) or Newtons (N), with softer woods scoring lower on the scale and harder woods scoring higher. The scale is widely accepted as the best means of ranking a wood’s hardness. In general, woods with a higher Janka rating are harder and more scratch-resistant, while woods with a lower Janka rating are softer and more prone to dents and wear.
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What Is Janka Rating? 2023
The Janka hardness scale was standardized in 1927 by the American Society for Testing and Materials (ASTM). It is used not only in the flooring industry but also in furniture-making and other woodworking applications to help determine the appropriate wood for a specific project. Understanding the Janka hardness scale is important when choosing wood for a project, as it can affect the wood’s durability and longevity.
What are types of wood ranked by hardness?
There are several types of wood ranked by hardness, with the Janka hardness ratings. Here are some examples of woods ranked by their Janka hardness ratings.
| Wood name | Janka hardness |
| Brazilian Walnut | 3684 |
| Ebony | 3220 |
| Brazilian Cherry | 2350 |
| Hard Maple | 1450 |
| Hickory/Pecan | 1820 |
| Ash | 1320 |
| Red Oak | 1290 |
| Birch | 1260 |
| White Oak | 1360 |
| Cherry | 995 |
| Cedar | 900 |
| Pine (Southern Yellow) | 690 |
| Douglas Fir | 660 |
| Balsa | 100 |
What is a good Janka rating?
The answer to that question depends on the intended use of the wood.
- A Janka rating of 1000 to 2000 is considered suitable for hardwood floors. This range includes popular hardwoods such as oak, maple, and hickory.
- A Janka rating of 800 to 1800 is typically recommended for engineered hardwood.
It’s important to note that a higher Janka rating doesn’t necessarily mean better. Some woods with extremely high Janka ratings, such as Brazilian walnut or Brazilian cherry, maybe too hard and challenging to work with. It’s also worth considering the aesthetic qualities of the wood, as some people may prefer the look of softer woods with lower Janka ratings.
What wood has the highest Janka rating?
If you’re curious about what wood has the highest Janka rating, it’s worth noting that the highest rating belongs to the Australian Buloke, with a rating of 5060. However, this wood is incredibly hard to find and work with, making it a less practical option for most people.
So, a good Janka rating is essential for ensuring the durability and longevity of your hardwood or engineered hardwood floors. It is also necessary to consider the aesthetic qualities of the wood and the practicality of working with extremely hard wood. By understanding the critical idea of the Janka rating, you can make an informed decision when choosing the right type of wood for your floors.
What is the Janka Rating For Acacia?
The Janka hardness rating for acacia wood varies depending on the species of acacia, with different sources citing different ratings.
The Janka hardness rating for large-leaf acacia is 1700, while small-leaf acacia has a rating of 2220, making acacia more durable than some of the most popular hardwood species available.
However, the Janka hardness rating for Babul Acacia is 2300 pounds of force, making it 55% harder than European White Oak, 23% harder than hickory, and 90% harder than carbonized bamboo.
It is important to note that Janka ratings vary widely among different acacia subspecies. For instance, the Australian Blackwood, also known as Acacia Blackwood, has a Janka rating of 1160 lbf, meaning it takes 1160 pounds of force to scratch the timber.
Remember, each acacia wood species falls within the range of 1100 to 2500 on the Janka scale, with acacia woods being, on average, over 50% harder than European White Oak, 20% harder than European White Oak hickory, and 90% harder than carbonized bamboo.
Why is Janka Rating important?
The Janka rating is vital for wood, especially in the lumber industry, and for those looking to use wood for specific applications such as hardwood floors, furniture, and butcher block countertops. The Janka rating measures the force needed to embed a steel ball halfway into a plank of wood and provide a standardized way to compare the hardness, resistance, and durability of different wood species.
Janka rating helps contractors, homeowners, and designers determine the durability of various species and provide a standard to which the durability of several species can be compared to one another.
Knowing the Janka rating of a particular type of wood is essential when selecting wood for specific applications, such as hardwood floors, where durability and wear resistance are critical factors. The rating allows homeowners to determine which type of wood suits their homes. It indirectly predicts the difficulty in nailing, screwing, sanding, or sawing a given wood species.
The Janka rating is an indication and should not be the sole determining factor. Factors such as traffic, maintenance, and prevention also play a role in the appearance and durability of a floor over time.
For instance, if you are building furniture, you may want to consider domestic hardwood like Hickory, Oak, or Maple, which have moderate to high Janka ratings and are known for their strength and durability. Softwoods like Pine and Cedar have low to moderate Janka ratings, making them ideal for construction, decorative projects, and outdoor applications. These woods are easy to work with and naturally resist decay and insects.
Nonetheless, the Janka rating is an essential tool for determining the hardness of wood and its ability to withstand wear and tear, making it a vital consideration for those who work with wood in any capacity.
Final words
Janka wood rating is the best scale that can help to choose wood for different wooden projects by determining the wood’s hardness and softness. For instance, Hardwoods like Brazilian Walnut (Ipe), Ebony, and Australian Buloke have high Janka ratings, making them suitable for flooring, decking, and outdoor furniture. If you are building a deck, you may want to consider a hardwood like Brazilian Walnut or Australian Buloke, which have high Janka ratings and are resistant to rot and decay. When choosing a wood species for a decorative project or accent piece, you may want to consider softwood like Cedar or Pine, which have low to moderate Janka ratings but are known for their unique grain patterns and natural beauty.
Frequently Asked Questions (FAQs)
Is a higher Janka rating better?
A higher Janka rating indicates greater hardness and resistance to the indentation in a wood species. While a higher Janka rating can be desirable for applications where durability is essential, it may not always be necessary or suitable for every project.
What is the lightest hardest wood?
Redwood is the lightest and most durable wood available on the building market. Heartwood redwood grades are typically the most durable.
Which wood flooring is the hardest?
Lapacho (Ipe) is the hardest and rarest wood for flooring. Remember, Lapacho is also one of the expensive hardwoods for flooring.
