Home / Wood Compare / Cumaru vs African Blackwood
Professional Comparison · Verified Engineering Data · Updated 19 July 2026
Cumaru VS African Blackwood
Which wood is better for your project? Scores are computed from the verified figures on each species page — how we score.
🥇
Cumaru
98/100 Library Score
🪵Hardwood🌧Outdoor🔥Low Flame Spread💧Moisture Stable
- Leads on stiffness, lightness, machining ease — a narrow but consistent edge
🥈
African Blackwood
94/100 Library Score
🪵Hardwood🌧Outdoor🔥Low Flame Spread💧Moisture Stable
- Close second across most categories
- Solid choice where its profile fits the project
Visual comparison
CumaruAfrican Blackwood
Winner by category
There isn't one universally best wood — there's a best wood for each purpose.
| Category | Winner |
|---|---|
| Durability | Tie |
| Stability | Tie |
| Hardness | Tie |
| Strength (MOR) | African Blackwood |
| Stiffness (MOE) | Cumaru |
| Flame spread | Tie |
| Machining ease | Tie |
| Lightness | Cumaru |
Engineering data
| Property | Cumaru | African Blackwood |
|---|---|---|
| Janka Hardness | 3330WD lbf | 3670WD lbf |
| Density | 0.87WD g/cm³ | 0.98WD g/cm³ |
| MOE | 22.33WD GPa | 17.95WD GPa |
| MOR | 175.1WD MPa | 213.0WD MPa |
| Durability | Class 1 Very Durable | Class 1 Very Durable |
| Stability | Excellent | Excellent |
| Fire (E84) | Class A indicative | Class A indicative |
| Radial Shrink | 5.3WD % | 2.9WD % |
| Tangential Shrink | 7.7WD % | 4.8WD % |
| T/R Ratio | 1.45 | 1.66 |
Figures carry the same source status as the species pages they come from — verified where cited, indicative where marked.
Best for
| Application | Recommended | Suitability |
|---|---|---|
| Outdoor decking / pergola | 🥇 Cumaru | ★★★★★ |
| Exterior cladding | 🥇 Cumaru | ★★★★☆ |
| Flooring / wear surfaces | 🥇 African Blackwood | ★★★★★ |
| Furniture / interior joinery | 🥇 Cumaru | ★★☆☆☆ |
| Structural / load-bearing | 🥇 Cumaru | ★★★★★ |
Advantages & limitations
Cumaru
Advantages
- Rated for exterior exposure (EN 350 Class 1)
- Very low movement in service
- Hard wear surface, dent-resistant
- Best flame-spread class (E84 Class A, indicative)
Limitations
- Hard on tooling; pre-drilling recommended
- Heavy — consider structure and handling
African Blackwood
Advantages
- Rated for exterior exposure (EN 350 Class 1)
- Very low movement in service
- Hard wear surface, dent-resistant
- Best flame-spread class (E84 Class A, indicative)
Limitations
- Hard on tooling; pre-drilling recommended
- Heavy — consider structure and handling
Recommendation
Choose Cumaru if…
- You want the stronger all-round engineering profile
Choose African Blackwood if…
- Its profile matches the application better than a single overall score
Frequently asked questions
Which is more durable, Cumaru or African Blackwood?
Neither — both carry the same EN 350 rating (Class 1, Very Durable). For outdoor decisions between them, weigh dimensional stability and hardness instead.
Which wood is better for outdoor use?
They are closely matched outdoors — durability and stability come out almost level. Let the application decide: harder surface for decking traffic, lighter weight for cladding.
Is Cumaru harder than African Blackwood?
No — African Blackwood is harder (Janka 3670 vs 3330 lbf).
How we score. Each wood gets a weighted composite of the verified figures shown above: durability 22%, stability 18%, hardness 12%, bending strength 12%, machining ease 12%, stiffness 8%, flame spread 8%, lightness 8%. The Library Score is that composite's percentile rank within our 60-species library — 50 means the library median, 90 means it outperforms nine of every ten species we cover. No price data is scored — cost guidance is qualitative. The score summarises the data; it does not replace judgement about your specific application.