Jack pine
Pinus banksiana
Jack pine measures 570 lbf on the Janka scale, about 44% as hard as northern red oak.
- On the Janka scale its nearest neighbours are red pine at 560 lbf and yellow-cedar at 580 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Jack pineU.S. softwoods medianOther woods
Shrinkage across the face
6.6%radial 3.7%32nd lowest of 1553.5%12.7%Stiffness
1.35 M psi9.3 GPa33rd most flexible of 1550.54 M psi4.06 M psiDensity
0.400.43 at 12% MC36th lightest of 1550.250.96Bending strength
9,900 psi68.3 MPa36th weakest of 1554,300 psi29,900 psiJanka hardness
570 lbf2,535 N40th softest of 15513th of 37 U.S. softwoods240 lbf3,680 lbfCupping tendency
1.7870th lowest of 1551.092.90
How much it moves
Its face shrinkage of 6.6% is in the lowest quarter of the list, with an ordinary T/R ratio of 1.78.
0.40 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.22 in.
- Tangential
- 6.6%
- Radial
- 3.7%
- Volume
- 10.3%
- T/R ratio
- 1.78 (70th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Ponderosa pine
19% softer · 5% lighter · shrinks 0.4 points less across the face
- Lodgepole pine
16% softer · 5% lighter · shrinks 0.1 points more across the face
- White fir
16% softer · 8% lighter · shrinks 0.4 points more across the face
Among the pines
7th hardest of 13, lbf; the neighbours either side are shown, the rest are on the pines page.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Modulus of elasticity | 1.07M psi | 1.35M psi | +26% | 9.31GPa |
| Work to maximum load | 7.20in-lbf/in³ | 8.30in-lbf/in³ | +15% | 57.2kJ/m³ |
| Modulus of rupture | 6,000psi | 9,900psi | +65% | 68.3MPa |
| Shear parallel to grain | 750psi | 1,170psi | +56% | 8.10MPa |
| Side hardness | 400lbf | 570lbf | +42% | 2,535N |
| Compression parallel to grain | 2,950psi | 5,660psi | +92% | 39MPa |
| Compression perpendicular | 300psi | 580psi | +93% | 4.00MPa |
| Tension perpendicular | 360psi | 420psi | +17% | 2.90MPa |
| Impact bending | 26in. | 27in. | +4% | 686mm |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides