Balsa
The lightest commercial timber, and a genuine hardwood despite the name — its cells are mostly empty. In composite sandwich panels it is used end-grain, with the fibres running through the thickness, where it carries shear between two thin skins at a fraction of the weight of solid laminate; whole wind turbine blades are built this way. Its stiffness-to-weight ratio along the grain is in the same league as steel, which is the reason it survived into engineering long after model aircraft stopped being the main market.
Properties
- Density
- 160 kg/m³ (100–250) — 0.16 g/cm³
- Young's modulus
- 3.4 GPa
- Floats in water
- Yes
- Magnetic
- No
What it is used for
- Model aircraft structure
- Sandwich panel cores in boat hulls and wind turbine blades
- Surfboard and paddleboard cores
- Packaging for delicate instruments
How it compares
Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.
| Material | Density | Relative to water |
|---|---|---|
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| balsa ← | 160 kg/m³ | 0.16× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |
Does it rust?
Balsa contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.
Is it magnetic?
Balsa is not a metal and has no ferromagnetic response.
Common questions
- What is the density of balsa?
- 160 kg/m³ (100–250), or 0.16 g/cm³.
- Does balsa float?
- Yes. At 160 kg/m³ it is less dense than water's 1,000.
- Is balsa magnetic?
- Balsa is not a metal and has no ferromagnetic response.
Related pages
- Does balsa float? Yes
- Pine 500 kg/m³
- Plywood 600 kg/m³
- MDF 750 kg/m³
- White oak 755 kg/m³
- Red oak 700 kg/m³
- Spruce 430 kg/m³
- Western red cedar 370 kg/m³
- Hard maple 705 kg/m³
Sources
- Typical range compiled from manufacturer specifications — At One Place