Balsa
Balsa is an extremely low-density hardwood, supplied kiln-dried (KD) or green and sorted into light (LD) and high (HD) density grades as well as end-grain core panels.
Reference datasheet — Balsa is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Balsa tempers and conditions
Balsa is supplied in 4 conditions, soft to hard.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
end-grain balsa sandwich core block (SB/AL series, ~0.15 g/cm³) | Use blocks cut and assembled with the fibres perpendicular to the panel face for wind-blade, hull and flooring sandwich cores; through-thickness compression and shear far exceed flat-grain sheet. | 12 | 1 | 0.06 W/m·K | ||
Low density select | Pick for weight-critical, lightly loaded parts — indoor models, racing wing ribs, ultralight filler cores — accepting the lowest strength and stiffness of the density selections. | 14 | 1.3 | 0.04 W/m·K | ||
Green / unseasoned | Treat freshly sawn stock above fibre saturation as an intermediate state before drying only; strength and stiffness are clearly below those of the dried material. | 17 | 2.2 | 0.11 W/m·K | ||
High density select | Choose the ~0.22 g/cm³ select cut for parts with local bearing, bolt or insert areas and higher shear loads, trading roughly double the weight of low-density stock. | 34 | 1.8 | 0.07 W/m·K |
Supply forms, finishes and certifications
Ways Balsa is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
KDDefault | Kiln-dried, medium density | Surface finish |
What is Balsa?
Balsa is an extremely low-density hardwood, supplied kiln-dried (KD) or green and sorted into light (LD) and high (HD) density grades as well as end-grain core panels. At 0.16 g/cm³ with 24 MPa tensile strength, 1.5 % elongation, 3.4 GPa modulus and 0.055 W/m·K conductivity, it gives one of the best stiffness-to-weight ratios available in a natural material and is used as sheet, block and end-grain sandwich core. Density varies between boards, the open cell structure absorbs water and resin unless sealed, and service is limited to about 90 °C. PVC or PET structural foam is the nearest synthetic core alternative. Balsa has a density of 0.16 g/cm³ (0.0058 lb/in³), lighter than 98% of natural material grades. Balsa has a tensile strength of 24 MPa (3.48 ksi), stronger than 55% of natural material grades. Elongation at break is 1.5% and the elastic modulus is 3.4 GPa (0.493 Msi).
What is Balsa used for?
- model aircraft
- surfboard cores
- sandwich panel cores
- thermal/acoustic insulation
- buoyancy floats
Advantages
- Lightweight — 0.16 g/cm³ (0.0058 lb/in³), better than 98% of natural material grades
- Easy to machine — 90/100, better than 86% of natural material grades
Limitations
- Low fracture toughness — 0.15 MPa·√m (0.137 ksi·√in), worse than 100% of natural material grades
- Poor heat conductor — 0.06 W/m·K (0.0318 BTU/hr·ft·°F), worse than 89% of natural material grades
- Hard to polish — 20/100, worse than 85% of natural material grades
- Needs corrosion protection — 30/100, worse than 77% of natural material grades
Balsa properties
Typical room-temperature values; bars are the position among natural material grades.
Physical2
Balsa has a density of 0.16 g/cm³ (0.0058 lb/in³), lighter than 98% of natural material grades.
Mechanical9
Balsa has a tensile strength of 24 MPa (3.48 ksi), stronger than 55% of natural material grades. Elongation at break is 1.5% and the elastic modulus is 3.4 GPa (0.493 Msi).
Thermal5
Balsa is rated for continuous service to 90°C (194 °F). It conducts heat at 0.06 W/m·K (0.0318 BTU/hr·ft·°F), worse than 89% of natural material grades. Thermal expansion is 4 µm/m·K (2.22 µin/in·°F).
Electrical1
Balsa has an electrical resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental1
Corrosion resistance is poor (30/100), worse than 77% of natural material grades.
Sustainability4
Producing a kilogram of Balsa takes about 8 MJ of energy and emits 0.45 kg of CO₂ — less than 74% of natural material grades. Typical recycled content is 0%.
Manufacturability2
Balsa's machinability is excellent (90/100, better than 86% of natural material grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Working with Balsa
Is Balsa easy to machine?
Cuts easily with sharp tooling at high spindle speed and light feed; blunt edges or excessive clamping pressure crush the cell structure, and laser cutting and steel-rule die cutting are both common.
Can Balsa be welded?
Not weldable; structural joints rely on epoxy, polyurethane or PVA adhesive, and end-grain core is co-cured bonded to the skins.
Can Balsa be formed, bent or molded?
Thin sheet softened with steam or hot water bends to small radii; thicker stock is shaped by block jointing or by laminating and gluing layers.
Balsa chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| cellulosecellulose, main load-bearing phase | 38 – 48 | 43 |
| hemicellulosehemicellulose | 20 – 30 | 25 |
| ligninlignin | 18 – 26 | 22 |
| extractives + ashextractives and ash | 1 – 6 | 3 |
| moisturekiln-dried equilibrium moisture content | 6 – 14 | 10 |
What surface finishes work on Balsa?
Seal the surface first with sanding sealer, thinned epoxy or heat-shrink film, otherwise the wood absorbs large amounts of water and resin and will not sand to a flat surface.
Equivalent designations
Standards and trade names that resolve to Balsa in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- Ochroma pyramidale
How much does Balsa cost?
Balsa is a premium-cost natural material ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Balsa — frequently asked
What is Balsa used for?
Balsa is typically used for model aircraft, surfboard cores, sandwich panel cores, thermal/acoustic insulation and buoyancy floats. In short: lowest-density structural wood; highest stiffness-to-weight timber; standard end-grain sandwich core.
What is the tensile strength of Balsa?
Balsa has a typical tensile strength of 24 MPa (3.48 ksi) — stronger than 55% of natural material grades. Strength varies by condition: see the 4 listed tempers.
Is Balsa easy to machine?
Yes — machinability is rated excellent (90/100, better than 86% of natural material grades). Cuts easily with sharp tooling at high spindle speed and light feed; blunt edges or excessive clamping pressure crush the cell structure, and laser cutting and steel-rule die cutting are both common.
Can Balsa be welded?
Not weldable; structural joints rely on epoxy, polyurethane or PVA adhesive, and end-grain core is co-cured bonded to the skins.
What surface finishes work on Balsa?
Seal the surface first with sanding sealer, thinned epoxy or heat-shrink film, otherwise the wood absorbs large amounts of water and resin and will not sand to a flat surface.
Can Balsa be formed, bent or molded?
Thin sheet softened with steam or hot water bends to small radii; thicker stock is shaped by block jointing or by laminating and gluing layers.
What is the maximum service temperature of Balsa?
Balsa is rated for continuous use to about 90°C (194 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Balsa cost?
Balsa is a premium-cost natural material ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Wood Handbook — Wood as an Engineering Material, FPL-GTR-190 — USDA Forest Products Laboratory (2021)
- ASTM D143 — Standard Test Methods for Small Clear Specimens of Timber — ASTM International (2022)
- BALTEK SB / AL End-Grain Balsa Core Data Sheets — 3A Composites Core Materials (2021)
- Cellular Solids: Structure and Properties — Gibson & Ashby, Cambridge University Press (1997)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.