Wood species
Sassafras wood
Sassafras is a hardwood (Sassafras albidum). It weighs about 32 lb/ft³ (515 kg/m³), 2.7 lb (1.22 kg) per board foot.
Key numbers
- Janka hardness, 12% MC
- Not measured
- Weight at 12% MC
- 32 lb/ft³ (515 kg/m³)
- 2.7 lb per board foot
- Specific gravity (oven-dry weight)
- 0.46 at 12% MC volume
- 0.42 on green volume
- Shrinkage, green to oven-dry
- 6.2% tangential
- Radial 4.0%, volumetric 10.3%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; sassafras's density is worked from its specific gravity with the Handbook's own equation.
How much sassafras moves
A 12 in wide flatsawn board of sassafras that goes from 6% to 12% moisture content swells about 0.16 in (about 5/32 in, 4 mm). Quartersawn, the same board moves about 0.1 in (about 3/32 in, 2.5 mm). Flatsawn faces move 1.6 times as much as quartersawn ones, because the wood shrinks 6.2% around the growth rings but only 4.0% across them.
Worked with the Wood Handbook's dimensional change coefficients for sassafras (Table 13-5: 0.00216 tangential, 0.00137 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
- Light yellow sapwood; heartwood dull grayish brown to dark brown, sometimes reddish.
- Grain and texture
- Looks much like black ash in color, grain and texture. Fresh-cut surfaces have a distinctive smell.
- Working and character
- Moderately heavy and moderately hard, quite high in shock resistance, and decay resistant.
- Uses
- Small boats, fence posts and rails, and general millwork.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-9.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of sassafras 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) | 6,000 psi (41 MPa) | 9,000 psi (62 MPa) |
| Stiffness (MOE) | 910,000 psi (6.3 GPa) | 1,120,000 psi (7.7 GPa) |
| Crushing strength (compression parallel to grain) | 2,730 psi (19 MPa) | 4,760 psi (33 MPa) |
| Compression perpendicular to grain | 370 psi (3 MPa) | 850 psi (6 MPa) |
| Shear parallel to grain | 950 psi (7 MPa) | 1,240 psi (9 MPa) |
| Tension perpendicular to grain | — | — |
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 Wood Handbook prints no side hardness for sassafras (Table 5-3b shows "—"), so none is given here.
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 × 0.46 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 32 lb/ft³, or 2.7 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources