Black spruce
Picea mariana
Black spruce measures 530 lbf on the Janka scale, about 41% as hard as northern red oak.
- Of the three spruces in the handbook, none is harder, heavier or stiffer, and none shrinks less across the face or has a T/R ratio closer to 1.
- Across all 155 woods it falls in the bottom fifth for density.
- On the Janka scale its nearest neighbours are Sitka spruce at 510 lbf and American chestnut at 540 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Black spruceU.S. softwoods medianOther woods
Density
0.380.42 at 12% MC28th lightest of 1550.250.96Janka hardness
530 lbf2,358 N34th softest of 15516th of 37 U.S. softwoods240 lbf3,680 lbfShrinkage across the face
6.8%radial 4.1%40th lowest of 1553.5%12.7%Bending strength
10,800 psi74.5 MPa48th weakest of 1554,300 psi29,900 psiCupping tendency
1.6651st lowest of 1551.092.90Stiffness
1.61 M psi11.1 GPa71st most flexible of 1550.54 M psi4.06 M psi
For its weight: stiffness-to-weight 4.24 (14th of 155).
How much it moves
Both its face shrinkage (6.8%) and its T/R ratio (1.66) sit in the middle half of the list.
0.41 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.25 in.
- Tangential
- 6.8%
- Radial
- 4.1%
- Volume
- 11.3%
- T/R ratio
- 1.66 (51st most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Red pine
6% harder · 8% heavier · shrinks 0.4 points more across the face
- Sitka spruce
4% softer · 3% lighter · shrinks 0.7 points more across the face
- Western hemlock
2% harder · 10% heavier · shrinks 1.0 points more across the face
Among the spruces
1st hardest of 3, lbf.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Side hardness | 340lbf | 530lbf | +56% | 2,358N |
| Compression perpendicular | 240psi | 550psi | +129% | 3.80MPa |
| Impact bending | 24in. | 23in. | −4% | 584mm |
| Shear parallel to grain | 740psi | 1,230psi | +66% | 8.50MPa |
| Modulus of rupture | 6,100psi | 10,800psi | +77% | 74.5MPa |
| Compression parallel to grain | 2,840psi | 5,960psi | +110% | 41.1MPa |
| Work to maximum load | 7.40in-lbf/in³ | 10.5in-lbf/in³ | +42% | 72.4kJ/m³ |
| Modulus of elasticity | 1.38M psi | 1.61M psi | +17% | 11.1GPa |
| Tension perpendicular | 100psi | not tested | — | — |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides