Kusia
Scientific name: Nauclea diderrichii
Overview
Kusia is a dense and highly durable hardwood native to West and Central Africa. It is known for its strength, resistance to decay, and suitability for heavy-duty applications, particularly in outdoor and structural environments.
Often used as a substitute for other heavy tropical hardwoods, Kusia performs well in conditions requiring long-term durability.
Quick Facts
- Common Name: Kusia (Bilinga)
- Scientific Name: Nauclea diderrichii
- Region: African Hardwoods (West & Central Africa)
- Tree Size: 100–150 ft tall, 3–5 ft trunk diameter
- Average Dried Weight: 50 lbs/ft³ (800 kg/m³)
- Janka Hardness: 1,820 lbf
- Color: Yellowish brown to medium brown
- Grain: Interlocked
- Texture: Medium to coarse
Identification Characteristics
Kusia is identified by its yellow-brown coloration and relatively coarse texture. The grain is typically interlocked, and the wood has a noticeably heavy feel.
Key identification traits include:
- Yellowish to medium-brown heartwood
- Interlocked grain
- Medium to coarse texture
- High density and weight
Working Properties
Kusia is moderately difficult to work due to its density and grain structure.
- Machines with some difficulty
- Interlocked grain may cause tear-out
- Pre-drilling recommended
- Glues and finishes adequately
- Very durable
Safety Note
Dust may cause irritation. Standard protective measures are recommended.
Common Uses
Kusia is commonly used in applications requiring strength and durability.
- Heavy construction
- Marine applications
- Railway ties
- Outdoor structures
- Industrial use
Sustainability & Notes
Kusia is not listed under CITES, but it is harvested in limited regions. Responsible sourcing is recommended.
Comparative Notes & Related Species
Azobe – Significantly denser and harder, used in more extreme structural applications.
Okan – Similar use in heavy construction, though generally heavier and more durable.
Iroko – Lighter and easier to work, often used in more general outdoor applications.
Related Guides
Machining Dense Tropical Hardwoods
Important for working dense species like Kusia.
Density & Hardness Explained (Janka Scale Guide)
Helps compare Kusia to other hardwoods.
Understanding Interlocked vs Straight Grain
Useful for managing machining challenges.
Compare Wood Properties
See how this species ranks in density and hardness using our Wood Density & Janka Hardness Chart. You can also explore Hardest Woods, Softest Woods, and Most Dense Woods for quick comparisons.
Collector Notes
Kusia is included in collections as a representative of durable, heavy-use African hardwoods. It serves as a useful comparison between mid-density structural woods and ultra-dense species like Azobe.
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Wood Sample Collection
This species is part of an ongoing effort to document and preserve wood samples from around the world.
Learn more about contributing to the collection:
Resources
Authoritative botanical and forestry references used in compiling information about this species include:
• USDA Forest Service – Wood Handbook: Wood as an Engineering Material
https://www.fpl.fs.usda.gov/products/publications/
• The Wood Database – Global reference for wood identification, physical properties, and woodworking characteristics
https://www.wood-database.com/
• Royal Botanic Gardens, Kew – Plants of the World Online – Botanical taxonomy and species distribution database
https://powo.science.kew.org/
• International Union for Conservation of Nature (IUCN Red List) – Global conservation status assessments
https://www.iucnredlist.org/
• Convention on International Trade in Endangered Species (CITES) – International trade regulations for protected plant species
https://cites.org/
Additional forestry publications, academic research papers, and regional timber studies may also be referenced where available.
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Availability & Where to Buy
Exotic hardwood availability can vary significantly depending on region, sustainability regulations, and supplier inventory.
As this archive grows, recommended suppliers and specialty wood retailers will be listed here to help woodworkers locate responsibly sourced material.
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