A light, machinable straight, coarse-grained fast-growing hardwood, supposedly known as "The Aluminum of Hardwoods". Supposedly bug and water resistant, Sounds almost too good to be true...
Common Name(s): Paulownia, Royal Paulownia, Princess Tree, Kiri
Scientific Name: Paulownia tomentosa
Distribution: Native to eastern Asia; also planted in eastern North America
Tree Size: 30-65 ft (10-20 m) tall, 2-4 ft (.6-1.2 m) trunk diameter
Average Dried Weight: 18 lbs/ft3 (280 kg/m3) (Aluminum: 168.48 lbs/ft3)
Specific Gravity (Basic, 12% MC): .25, .28 (Aluminum 2.7)
Janka Hardness: 300 lbf (1,330 N)
Modulus of Rupture: 5,480 lbf/in2 (37.8 MPa)
Elastic Modulus: 635,000 lbf/in2 (4.38 GPa)
Crushing Strength: 3,010 lbf/in2 (20.7 MPa)
Shrinkage: Radial: 2.4%, Tangential: 3.9%, Volumetric: 6.4%, T/R Ratio: 1.6
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Sitka spruce – physical properties
Common Name(s): Paulownia, Royal Paulownia, Princess Tree, Kiri
Scientific Name: Paulownia tomentosa
Distribution: Native to eastern Asia; also planted in eastern North America
Tree Size: 30-65 ft (10-20 m) tall, 2-4 ft (.6-1.2 m) trunk diameter
Average Dried Weight: 18 lbs/ft3 (280 kg/m3) (Aluminum: 168.48 lbs/ft3)
Specific Gravity (Basic, 12% MC): .25, .28 (Aluminum 2.7)
Janka Hardness: 300 lbf (1,330 N)
Modulus of Rupture: 5,480 lbf/in2 (37.8 MPa)
Elastic Modulus: 635,000 lbf/in2 (4.38 GPa)
Crushing Strength: 3,010 lbf/in2 (20.7 MPa)
Shrinkage: Radial: 2.4%, Tangential: 3.9%, Volumetric: 6.4%, T/R Ratio: 1.6
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Sitka spruce – physical properties
| Density (kg/m3) | Green | 347 |
| Air dry | 387 | |
| Specific gravity (12% m.c.) | Standard | 0.35 |
| Hardness (N) | Side | 2200 |
| End | 3090 | |
| MOE (Mpa) | Green | 9450 |
| Air dry | 11200 | |
| MOR (Mpa) | Green | 37.4 |
| Air dry | 69.8 | |
| Compression parallel (Mpa) | Air dry | 37.4 |
| Compression perpendicular (Mpa) | Air dry | 4.10 |
| Shear (Mpa) | Air dry | 6.78 |
| Cleavage (N/mm width) | Air dry | 38.0 |
| Shrinkage OD = oven dry air = air dry 12% | Radial (OD) | 4.6% |
| Tangential (OD) | 7.8% | |
| Volumetric (OD) | 11.7% | |
| Volumetric (air) | 6.0% | |
| Tang / rad ratio | 1.7 |
