Hackberry
Celtis occidentalis
Hackberry measures 880 lbf on the Janka scale, 32% softer than northern red oak.
- Water tupelo has exactly the same Janka figure.
- Across all 155 woods it falls in the bottom fifth for stiffness.
- On the Janka scale its nearest neighbours are longleaf pine at 870 lbf and sande at 900 lbf.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
HackberryU.S. hardwoods medianOther woods
Stiffness
1.19 M psi8.2 GPa17th most flexible of 15526% below the U.S. hardwoods median0.54 M psi4.06 M psiShrinkage across the face
8.9%radial 4.8%44th highest of 1553.5%12.7%Bending strength
11,000 psi75.8 MPa51st weakest of 1554,300 psi29,900 psiCupping tendency
1.8572nd highest of 1551.092.90Janka hardness
880 lbf3,914 N73rd softest of 15535th of 53 U.S. hardwoods240 lbf3,680 lbfDensity
0.490.53 at 12% MC76th lightest of 1550.250.96
For its weight: stiffness-to-weight 2.43 (150th of 155); strength-to-weight 22,449 psi (138th of 155).
How much it moves
Both its face shrinkage (8.9%) and its T/R ratio (1.85) sit in the middle half of the list.
0.53 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.29 in.
- Tangential
- 8.9%
- Radial
- 4.8%
- Volume
- 13.8%
- T/R ratio
- 1.85 (83rd most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Black tupelo
8% softer · 6% lighter · shrinks 0.2 points less across the face
- American sycamore
12% softer · 6% lighter · shrinks 0.5 points less across the face
- American elm
6% softer · 6% lighter · shrinks 0.6 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 |
|---|---|---|---|---|
| Modulus of elasticity | 0.95M psi | 1.19M psi | +25% | 8.20GPa |
| Impact bending | 48in. | 43in. | −10% | 1,092mm |
| Compression parallel to grain | 2,650psi | 5,440psi | +105% | 37.5MPa |
| Modulus of rupture | 6,500psi | 11,000psi | +69% | 75.8MPa |
| Compression perpendicular | 400psi | 890psi | +123% | 6.10MPa |
| Tension perpendicular | 630psi | 580psi | −8% | 4.00MPa |
| Work to maximum load | 14.5in-lbf/in³ | 12.8in-lbf/in³ | −12% | 88.3kJ/m³ |
| Side hardness | 700lbf | 880lbf | +26% | 3,914N |
| Shear parallel to grain | 1,070psi | 1,590psi | +49% | 11MPa |
Wood Handbook Table 5-3b, Table 4-3. Data & method · Guides