Wood species
Black maple wood
Black maple is a hardwood (Acer nigrum). At 12% moisture content it has a Janka hardness of 1,180 lbf (5,249 N) and it weighs about 40 lb/ft³ (638 kg/m³), 3.3 lb (1.51 kg) per board foot.
Also called: black sugar maple, Acer nigrum.
Key numbers
- Janka hardness, 12% MC
- 1,180 lbf (5,249 N)
- Green: 840 lbf (3,737 N)
- Weight at 12% MC
- 40 lb/ft³ (638 kg/m³)
- 3.3 lb per board foot
- Specific gravity (oven-dry weight)
- 0.57 at 12% MC volume
- 0.52 on green volume
- Shrinkage, green to oven-dry
- 9.3% tangential
- Radial 4.8%, volumetric 14.0%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; black maple's density is worked from its specific gravity with the Handbook's own equation.
How much black maple moves
A 12 in wide flatsawn board of black maple 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 0.12 in (about 1/8 in, 3 mm). Flatsawn faces move 1.9 times as much as quartersawn ones, because the wood shrinks 9.3% around the growth rings but only 4.8% across them.
Worked with the Wood Handbook's dimensional change coefficients for black maple (Table 13-5: 0.0033 tangential, 0.00165 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
- Usually light reddish brown heartwood, sometimes much darker; white sapwood with a slight reddish tinge.
- Grain and texture
- Fine, uniform texture.
- Working and character
- One of the two hard maples, with sugar maple: heavy, strong, stiff, hard and shock resistant, with high shrinkage.
- Uses
- Hard maple goes into flooring, furniture, cabinets, cutting boards, pianos, handles, bowling alleys and gym floors.
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 black 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) | 7,900 psi (54 MPa) | 13,300 psi (92 MPa) |
| Stiffness (MOE) | 1,330,000 psi (9.2 GPa) | 1,620,000 psi (11.2 GPa) |
| Crushing strength (compression parallel to grain) | 3,270 psi (23 MPa) | 6,680 psi (46 MPa) |
| Compression perpendicular to grain | 600 psi (4 MPa) | 1,020 psi (7 MPa) |
| Shear parallel to grain | 1,130 psi (8 MPa) | 1,820 psi (13 MPa) |
| Tension perpendicular to grain | 720 psi (5 MPa) | 670 psi (5 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 black maple
Work it out for your project
- Rank woods for furniture with the species picker
Weigh black maple against other woods on hardness, weight, movement and color, every figure from the Wood Handbook.
- Plan a finish for furniture in black 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 black maple at 1,180 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 × 0.57 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 40 lb/ft³, or 3.3 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources