Yellow-poplar
Liriodendron tulipifera
Yellow-poplar measures 540 lbf on the Janka scale, about 42% as hard as northern red oak.
- American chestnut and western hemlock have exactly the same Janka figure.
- On the Janka scale its nearest neighbours are black spruce at 530 lbf and hura at 550 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
Yellow-poplarU.S. hardwoods medianOther woods
Janka hardness
540 lbf2,402 N35th softest of 15547th of 53 U.S. hardwoods; 53% below the U.S. hardwoods median240 lbf3,680 lbfDensity
0.400.42 at 12% MC36th lightest of 1550.250.96Bending strength
10,100 psi69.6 MPa40th weakest of 1554,300 psi29,900 psiShrinkage across the face
8.2%radial 4.6%64th highest of 1553.5%12.7%Stiffness
1.58 M psi10.9 GPa65th most flexible of 1550.54 M psi4.06 M psiCupping tendency
1.7870th lowest of 1551.092.90
How much it moves
Both its face shrinkage (8.2%) and its T/R ratio (1.78) sit in the middle half of the list.
0.49 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.28 in.
- Tangential
- 8.2%
- Radial
- 4.6%
- Volume
- 12.7%
- T/R ratio
- 1.78 (70th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Ilomba
13% harder · same density · shrinks 0.2 points more across the face
- Red alder
9% harder · 8% lighter · shrinks 0.9 points less across the face
- Light red meranti
15% softer · 15% lighter · shrinks 0.3 points more across the face
Woods of similar hardness
The eight nearest on the Janka scale, lbf.
Laboratory values
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Compression perpendicular | 270psi | 500psi | +85% | 3.40MPa |
| Side hardness | 440lbf | 540lbf | +23% | 2,402N |
| Compression parallel to grain | 2,660psi | 5,540psi | +108% | 38.2MPa |
| Modulus of rupture | 6,000psi | 10,100psi | +68% | 69.6MPa |
| Shear parallel to grain | 790psi | 1,190psi | +51% | 8.20MPa |
| Work to maximum load | 7.50in-lbf/in³ | 8.80in-lbf/in³ | +17% | 60.7kJ/m³ |
| Impact bending | 26in. | 24in. | −8% | 610mm |
| Tension perpendicular | 510psi | 540psi | +6% | 3.70MPa |
| Modulus of elasticity | 1.22M psi | 1.58M psi | +30% | 10.9GPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides