Sitka spruce
Picea sitchensis
Sitka spruce measures 510 lbf on the Janka scale, about 40% as hard as northern red oak.
- Of the three spruces in the handbook, none shrinks more across the face.
- Banak has exactly the same Janka figure.
- Across all 155 woods it falls in the bottom fifth for density.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Sitka spruceU.S. softwoods medianOther woods
Density
0.370.40 at 12% MC23rd lightest of 1550.250.96Janka hardness
510 lbf2,269 N32nd softest of 15517th of 37 U.S. softwoods240 lbf3,680 lbfBending strength
10,200 psi70.3 MPa41st weakest of 1554,300 psi29,900 psiStiffness
1.57 M psi10.8 GPa63rd most flexible of 1550.54 M psi4.06 M psiShrinkage across the face
7.5%radial 4.3%65th lowest of 1553.5%12.7%Cupping tendency
1.7466th lowest of 1551.092.90
For its weight: stiffness-to-weight 4.24 (12th of 155).
How much it moves
Both its face shrinkage (7.5%) and its T/R ratio (1.74) sit in the middle half of the list.
0.45 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.26 in.
- Tangential
- 7.5%
- Radial
- 4.3%
- Volume
- 11.5%
- T/R ratio
- 1.74 (66th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- California red fir
2% softer · 3% lighter · shrinks 0.4 points more across the face
- Black spruce
4% harder · 3% heavier · shrinks 0.7 points less across the face
- Western white pine
18% softer · 5% lighter · shrinks 0.1 points less across the face
Among the spruces
2nd hardest of 3, lbf.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Side hardness | 350lbf | 510lbf | +46% | 2,269N |
| Shear parallel to grain | 760psi | 1,150psi | +51% | 7.90MPa |
| Compression parallel to grain | 2,670psi | 5,610psi | +110% | 38.7MPa |
| Modulus of rupture | 5,700psi | 10,200psi | +79% | 70.3MPa |
| Compression perpendicular | 280psi | 580psi | +107% | 4.00MPa |
| Tension perpendicular | 250psi | 370psi | +48% | 2.60MPa |
| Work to maximum load | 6.30in-lbf/in³ | 9.40in-lbf/in³ | +49% | 64.8kJ/m³ |
| Impact bending | 24in. | 25in. | +4% | 635mm |
| Modulus of elasticity | 1.23M psi | 1.57M psi | +28% | 10.8GPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides