Wood species
Magnolia wood
Magnolia is a hardwood; this page covers the magnolia, led by southern magnolia (Magnolia grandiflora). At 12% moisture content it has a Janka hardness of 1,020 lbf (4,537 N) and it weighs about 35 lb/ft³ (560 kg/m³), 2.9 lb (1.32 kg) per board foot.
Names and species on this page: southern magnolia, cucumbertree, sweetbay.
Key numbers
- Janka hardness, 12% MC
- 1,020 lbf (4,537 N)
- Green: 740 lbf (3,292 N)
- Weight at 12% MC
- 35 lb/ft³ (560 kg/m³)
- 2.9 lb per board foot
- Specific gravity (oven-dry weight)
- 0.50 at 12% MC volume
- 0.46 on green volume
- Shrinkage, green to oven-dry
- 6.6% tangential
- Radial 5.4%, volumetric 12.3%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; magnolia's density is worked from its specific gravity with the Handbook's own equation.
How much magnolia moves
A 12 in wide flatsawn board of southern magnolia that goes from 6% to 12% moisture content swells about 0.17 in (about 5/32 in, 4.2 mm). Quartersawn, the same board moves about 0.13 in (about 1/8 in, 3.4 mm). Flatsawn faces move 1.2 times as much as quartersawn ones, because the wood shrinks 6.6% around the growth rings but only 5.4% across them.
Worked with the Wood Handbook's dimensional change coefficients for southern magnolia (Table 13-5: 0.0023 tangential, 0.00187 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
- Yellowish white sapwood and light to dark brown heartwood with a yellow or green tinge.
- Grain and texture
- Close, uniform texture, generally straight; it closely resembles yellow-poplar.
- Working and character
- Moderately heavy and moderately hard, fairly low in shrinkage and in bending strength.
- Uses
- Furniture, boxes, pallets, venetian blinds, sashes, doors, veneer and millwork.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-8.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of southern magnolia 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) | 6,800 psi (47 MPa) | 11,200 psi (77 MPa) |
| Stiffness (MOE) | 1,110,000 psi (7.7 GPa) | 1,400,000 psi (9.7 GPa) |
| Crushing strength (compression parallel to grain) | 2,700 psi (19 MPa) | 5,460 psi (38 MPa) |
| Compression perpendicular to grain | 460 psi (3 MPa) | 860 psi (6 MPa) |
| Shear parallel to grain | 1,040 psi (7 MPa) | 1,530 psi (11 MPa) |
| Tension perpendicular to grain | 610 psi (4 MPa) | 740 psi (5 MPa) |
A dash means the Handbook prints no value; none is filled in.
The magnolia
The Handbook tests each species separately; they are sold together as magnolia. Across the 2 species measured, Janka hardness at 12% runs from 700 to 1,020 lbf.
| Species | Janka, 12% MC | Weight, 12% MC | Tangential shrinkage |
|---|---|---|---|
| Southern magnoliaMagnolia grandiflora | 1,020 lbf | 35 lb/ft³ | 6.6% |
| CucumbertreeMagnolia acuminata | 700 lbf | 34 lb/ft³ | 8.8% |
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 southern magnolia at 1,020 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 × 0.50 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 35 lb/ft³, or 2.9 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources