Redwood (old-growth)
Sequoia sempervirens
Redwood (old-growth) measures 480 lbf on the Janka scale, about 37% as hard as northern red oak.
- Only macawood loses less volume on drying, and only four woods shrink less across the face and eight shrink less through the thickness.
- It is soft and steady at once, in the lowest quarter of the list for both hardness and shrinkage across the face.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Redwood (old-growth)U.S. softwoods medianOther woods
Shrinkage across the face
4.4%radial 2.6%5th lowest of 15538% below the U.S. softwoods median3.5%12.7%Janka hardness
480 lbf2,135 N24th softest of 15521st of 37 U.S. softwoods240 lbf3,680 lbfDensity
0.380.40 at 12% MC28th lightest of 1550.250.96Stiffness
1.34 M psi9.2 GPa30th most flexible of 1550.54 M psi4.06 M psiBending strength
10,000 psi68.9 MPa38th weakest of 1554,300 psi29,900 psiCupping tendency
1.6958th lowest of 1551.092.90
How much it moves
Its face shrinkage of 4.4% is in the lowest quarter of the list, with an ordinary T/R ratio of 1.69.
0.26 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.16 in.
- Tangential
- 4.4%
- Radial
- 2.6%
- Volume
- 6.8%
- T/R ratio
- 1.69 (58th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Redwood (young-growth)
12% softer · 10% lighter · shrinks 0.5 points more across the face
- Sugar pine
21% softer · 10% lighter · shrinks 1.2 points more across the face
- Yellow-cedar
21% harder · 10% heavier · shrinks 1.6 points more across the face
Woods of similar hardness
The eight nearest on the Janka scale, lbf.
Laboratory values
Its most unusual laboratory figure is tension across the grain: 5th lowest of the 73 woods with a published value.
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Tension perpendicular | 260psi | 240psi | −8% | 1.70MPa |
| Shear parallel to grain | 800psi | 940psi | +18% | 6.50MPa |
| Impact bending | 21in. | 19in. | −10% | 483mm |
| Work to maximum load | 7.40in-lbf/in³ | 6.90in-lbf/in³ | −7% | 47.6kJ/m³ |
| Side hardness | 410lbf | 480lbf | +17% | 2,135N |
| Modulus of elasticity | 1.18M psi | 1.34M psi | +14% | 9.24GPa |
| Modulus of rupture | 7,500psi | 10,000psi | +33% | 68.9MPa |
| Compression parallel to grain | 4,200psi | 6,150psi | +46% | 42.4MPa |
| Compression perpendicular | 420psi | 700psi | +67% | 4.80MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides