Douglas Fir VS African Mahogany
- Easier machining and fastening (lower density/hardness)
- Harder wear surface
- Solid choice where its profile fits the project
Visual comparison
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 | African Mahogany |
| Strength (MOR) | Douglas Fir |
| Stiffness (MOE) | Douglas Fir |
| Flame spread | African Mahogany |
| Machining ease | Douglas Fir |
| Lightness | Douglas Fir |
Engineering data
| Property | Douglas Fir | African Mahogany |
|---|---|---|
| Janka Hardness | 620WD lbf | 1070WD lbf |
| Density | 0.48FPL g/cm³ | 0.52FPL g/cm³ |
| MOE | 13.4FPL GPa | 9.7FPL GPa |
| MOR | 85.0FPL MPa | 78.6FPL MPa |
| Durability | Class 3 Moderately Durable | Class 3 Moderately Durable |
| Stability | Excellent | Excellent |
| Fire (E84) | Class C indicative | Class B indicative |
| Radial Shrink | 4.8WD % | 3WD % |
| Tangential Shrink | 7.6WD % | 5WD % |
| T/R Ratio | 1.58 | 1.67 |
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 | 🥇 Douglas Fir | ★★★★☆ |
| Exterior cladding | 🥇 Douglas Fir | ★★★★☆ |
| Flooring / wear surfaces | 🥇 African Mahogany | ★★★☆☆ |
| Furniture / interior joinery | 🥇 Douglas Fir | ★★★★☆ |
| Structural / load-bearing | 🥇 Douglas Fir | ★★★☆☆ |
Advantages & limitations
Douglas Fir
Advantages relative to African Mahogany
- MOE is 13.4 GPa vs 9.7 GPa, about 38% higher
Limitations relative to African Mahogany
- Janka is 620 lbf vs 1,070 lbf, about 42% lower
- Fire (E84) is Class C vs Class B — one class lower on flame-spread rating
African Mahogany
Advantages relative to Douglas Fir
- Janka is 1,070 lbf vs 620 lbf, about 73% harder
- Fire (E84) is Class B vs Class C — one class better on flame-spread rating
Limitations relative to Douglas Fir
- MOE is 9.7 GPa vs 13.4 GPa, about 28% lower
Recommendation
Choose Douglas Fir if…
- Structural and construction lumber, glulam beams and roof trusses, plywood and veneer, timber framing where the higher stiffness is the deciding factor
- Poles, marine pilings and railway crossties where structural performance under load is the specification
Choose African Mahogany if…
- Fine furniture, cabinetmaking, interior joinery and trim, doors and windows where dent resistance and a Class B fire class both matter in specification
- Decorative veneer and panelling where the harder surface is the working requirement
Frequently asked questions
Which is more durable, Douglas Fir or African Mahogany?
Neither — both carry the same EN 350 rating (Class 3, Moderately Durable). For outdoor work the separation is movement, not decay: African Mahogany moves 5.0% tangentially against 7.6%, which decides board width and fixing spacing more than the durability class does.
Which wood is better for outdoor use?
Both are EN 350 Class 3, and tangential movement runs 7.6% for Douglas Fir against 5.0% for African Mahogany — close enough that decay resistance will not choose between them, and African Mahogany holds its dimension marginally better. African Mahogany gives the harder wearing surface at 1,070 lbf; Douglas Fir is the lighter section at 0.48 g/cm³ — traffic favours the first, cladding and handling the second.
Is Douglas Fir harder than African Mahogany?
No — African Mahogany is harder (Janka 1070 vs 620 lbf).