Janka Hardness
Each exotic wood has a different durability level to distinguish it from other species.
Each exotic wood has a different durability level to distinguish it from other species. When considering using exotic woods, learn about their unique traits in order to pick the optimal wood for the job.
When it comes to determining the hardness of wood, the Janka hardness scale is the go to resource. The Janka rating is determined by embedding a .444 inch steel ball to half of its diameter into a sample of wood. This method leaves an indent in the wood which displays the dent and wear of the specific wood species. The higher the scale, the harder the wood will be. The Janka hardness scale is the standard for determining what the optimal applications of specific woods' characteristics are. Each exotic wood has a different durability level to distinguish it from other species. When considering using exotic woods, learn about their unique traits in order to pick the optimal wood for the job.
AFRICAN BLACKWOOD (Dalbergia melonoxylon)
With a fine and even texture, African Blackwood is known as one of the hardest and densest woods in the world. The wood is difficult to work under machine tools, as it often blunts the cutters. However, it is considered the finest wood species for turning. The color is often completely black, although sometimes it can be slightly lighter with a dark brown and purple hue. The thin and pale yellow sapwood is visibly divided from the dark heartwood. JANKA RATING OF 3670.
CUMARU (Dipteryx odorata)
With an excellent durability level, Cumaru is known for being strong, stiff and hard. The tree origin (from South America) comes from the Fabaceae family which contains seeds called tonka beans. The fragrance of the seeds consists of vanilla, almonds, cinnamon and clove. The Heartwood appearance consists of a medium to dark brown color. Oftentimes, there is reddish and a purplish hue along with pieces of yellowish or greenish streaks. JANKA RATING OF 3330.
Cumaru was used on the exterior of this LEED for Homes Platinum Level Residence in the state of Kansas. Image courtesy of Cilek.
Frequently asked questions
What is the Janka hardness scale and how is it measured?+
The Janka hardness scale is the standard resource for determining wood hardness. It is measured by embedding a .444 inch steel ball to half its diameter into a wood sample, leaving an indent that reveals the species' dent and wear resistance. The higher the rating, the harder the wood.
What is the Janka rating of African Blackwood?+
African Blackwood (Dalbergia melonoxylon) has a Janka rating of 3670, making it one of the hardest and densest woods in the world.
Why is African Blackwood difficult to machine?+
African Blackwood is extremely hard and dense, which often blunts machine cutters during work. Despite this, it is considered the finest wood species for turning.
What does African Blackwood look like?+
African Blackwood has a fine and even texture and is often completely black, though it can sometimes appear slightly lighter with a dark brown and purple hue. Its thin, pale yellow sapwood is visibly divided from the dark heartwood.
What are the characteristics and Janka rating of Cumaru wood?+
Cumaru (Dipteryx odorata) is strong, stiff, hard, and has excellent durability, with a Janka rating of 3330. Its heartwood is medium to dark brown, often with reddish or purplish hues and yellowish or greenish streaks.
Where does Cumaru wood come from and why does it smell fragrant?+
Cumaru originates from South America and belongs to the Fabaceae family. It produces seeds known as tonka beans, which carry a fragrance of vanilla, almonds, cinnamon, and clove.