Wood species
Bigleaf maple wood
Bigleaf maple is a hardwood (Acer macrophyllum). At 12% moisture content it has a Janka hardness of 850 lbf (3,781 N) and it weighs about 34 lb/ft³ (538 kg/m³), 2.8 lb (1.27 kg) per board foot.
Also called: Oregon maple, Acer macrophyllum.
Key numbers
- Janka hardness, 12% MC
- 850 lbf (3,781 N)
- Green: 620 lbf (2,758 N)
- Weight at 12% MC
- 34 lb/ft³ (538 kg/m³)
- 2.8 lb per board foot
- Specific gravity (oven-dry weight)
- 0.48 at 12% MC volume
- 0.44 on green volume
- Shrinkage, green to oven-dry
- 7.1% tangential
- Radial 3.7%, volumetric 11.6%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; bigleaf maple's density is worked from its specific gravity with the Handbook's own equation.
How much bigleaf maple moves
A 12 in wide flatsawn board of bigleaf maple that goes from 6% to 12% moisture content swells about 0.18 in (about 3/16 in, 4.5 mm). Quartersawn, the same board moves about 0.09 in (about 3/32 in, 2.3 mm). Flatsawn faces move 1.9 times as much as quartersawn ones, because the wood shrinks 7.1% around the growth rings but only 3.7% across them.
Worked with the Wood Handbook's dimensional change coefficients for bigleaf maple (Table 13-5: 0.00248 tangential, 0.00126 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
- Looks like the other maples; the sapwood is somewhat lighter than the heartwood.
- Working and character
- The Handbook counts bigleaf maple among the soft maples, the one that grows on the Pacific Coast; its own figures are in the table.
- Uses
- Soft maple goes into crossties, boxes, pallets, crates, furniture, veneer, wooden ware and novelties.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-8 to 2-9.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of bigleaf maple 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) | 7,400 psi (51 MPa) | 10,700 psi (74 MPa) |
| Stiffness (MOE) | 1,100,000 psi (7.6 GPa) | 1,450,000 psi (10 GPa) |
| Crushing strength (compression parallel to grain) | 3,240 psi (22 MPa) | 5,950 psi (41 MPa) |
| Compression perpendicular to grain | 450 psi (3 MPa) | 750 psi (5 MPa) |
| Shear parallel to grain | 1,110 psi (8 MPa) | 1,730 psi (12 MPa) |
| Tension perpendicular to grain | 600 psi (4 MPa) | 540 psi (4 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
Buying and finishing bigleaf maple
Work it out for your project
- Rank woods for furniture with the species picker
Weigh bigleaf maple against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.
- Plan a finish for furniture in bigleaf maple
The finishes whose makers name that use, and a dated coat schedule from each product’s own sheet.
Why these numbers
Why these numbers?
The situation
The USDA Forest Products Laboratory measured bigleaf maple at 850 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 × 0.48 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 34 lb/ft³, or 2.8 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources