Wood species
Basswood wood
Basswood is a hardwood (Tilia americana). At 12% moisture content it has a Janka hardness of 410 lbf (1,824 N) and it weighs about 26 lb/ft³ (414 kg/m³), 2.2 lb (0.98 kg) per board foot.
Also called: American basswood, linden, white basswood.
Key numbers
- Janka hardness, 12% MC
- 410 lbf (1,824 N)
- Green: 250 lbf (1,112 N)
- Weight at 12% MC
- 26 lb/ft³ (414 kg/m³)
- 2.2 lb per board foot
- Specific gravity (oven-dry weight)
- 0.37 at 12% MC volume
- 0.32 on green volume
- Shrinkage, green to oven-dry
- 9.3% tangential
- Radial 6.6%, volumetric 15.8%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; basswood's density is worked from its specific gravity with the Handbook's own equation.
How much basswood moves
A 12 in wide flatsawn board of American basswood that goes from 6% to 12% moisture content swells about 0.24 in (about 1/4 in, 6 mm). Quartersawn, the same board moves about 0.17 in (about 5/32 in, 4.2 mm). Flatsawn faces move 1.4 times as much as quartersawn ones, because the wood shrinks 9.3% around the growth rings but only 6.6% across them.
Worked with the Wood Handbook's dimensional change coefficients for American basswood (Table 13-5: 0.0033 tangential, 0.0023 radial per 1% change in moisture content), which hold between 6% and 14%. Individual boards vary: the Handbook gives shrinkage a coefficient of variation of about 15% (p. 4-11).
Color, grain and working
- Color
- Pale yellowish brown heartwood, sometimes with darker streaks, and wide creamy white to pale brown sapwood.
- Grain and texture
- Fine, even texture and straight grain.
- Working and character
- Soft and light, easy to work with hand tools, odorless and tasteless when dry. It shrinks a lot while drying but seldom warps in use.
- Uses
- A favorite of wood carvers; also venetian blinds, sashes and door frames, molding, beekeeping supplies, wooden ware and boxes.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-4 to 2-5.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of American basswood tested by the Forest Products Laboratory (Wood Handbook Table 5-3b). Knots and cross grain make lumber weaker than these clear samples (Handbook Chapter 5).
| Property | Green | 12% MC |
|---|---|---|
| Bending strength (MOR) | 5,000 psi (34 MPa) | 8,700 psi (60 MPa) |
| Stiffness (MOE) | 1,040,000 psi (7.2 GPa) | 1,460,000 psi (10.1 GPa) |
| Crushing strength (compression parallel to grain) | 2,220 psi (15 MPa) | 4,730 psi (33 MPa) |
| Compression perpendicular to grain | 170 psi (1 MPa) | 370 psi (3 MPa) |
| Shear parallel to grain | 600 psi (4 MPa) | 990 psi (7 MPa) |
| Tension perpendicular to grain | 280 psi (2 MPa) | 350 psi (2 MPa) |
A dash means the Handbook prints no value; none is filled in.
Dust and health
- Wood dust is classed as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer, chiefly for cancers of the nose and sinuses.
- NIOSH recommends keeping wood dust exposure to 1 mg/m³ of total dust, as quoted in OSHA's sawmill guidance.
This is what the named authorities publish, not medical advice.
Compare with
Why these numbers
Why these numbers?
The situation
The USDA Forest Products Laboratory measured American basswood at 410 lbf of side hardness at 12% moisture content, on clear, straight-grained samples (Wood Handbook Table 5-3b).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
What that means
Side hardness (Janka) is the load needed to press a 0.444 in (11.28 mm) steel ball halfway into the wood across the grain; a higher number dents less (Handbook p. 5-5).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
So
Density at 12% is water's density × specific gravity × (1 + 0.12) (Handbook Eq. 4-14): 62.43 × 0.37 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 26 lb/ft³, or 2.2 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources