Hura
Hura crepitans
Hura measures 550 lbf on the Janka scale, about 43% as hard as northern red oak.
- Of the 155 woods, only five shrink less across the face and six lose less volume on drying.
- It is soft and steady at once, in the lowest quarter of the list for both hardness and shrinkage across the face.
- Its bending strength is 48% below the median for imported woods.
U.S. hardwoodsU.S. softwoodsImported woodsNorthern red oak
Six measures
HuraImported woods medianOther woods
Shrinkage across the face
4.5%radial 2.7%6th lowest of 15543% below the imported woods median3.5%12.7%Stiffness
1.17 M psi8.1 GPa14th most flexible of 15542% below the imported woods median0.54 M psi4.06 M psiBending strength
8,700 psi60.0 MPa19th weakest of 15548% below the imported woods median4,300 psi29,900 psiDensity
0.3828th lightest of 15538% below the imported woods median0.250.96Janka hardness
550 lbf2,447 N38th softest of 15558th of 65 imported woods; 58% below the imported woods median240 lbf3,680 lbfCupping tendency
1.6754th lowest of 1551.092.90
How much it moves
Its face shrinkage of 4.5% is in the lowest quarter of the list, with an ordinary T/R ratio of 1.67.
0.27 in.
off a 6-inch flatsawn board, green to oven-dry; quartersawn 0.16 in.
- Tangential
- 4.5%
- Radial
- 2.7%
- Volume
- 7.3%
- T/R ratio
- 1.67 (54th most stable of 155)
End view, shrinkage drawn 3× life size.
Closest substitutes
- Cativo
14% harder · 5% heavier · shrinks 0.8 points more across the face
- Primavera
20% harder · 5% heavier · shrinks 0.6 points more across the face
- African mahogany
51% harder · 10% heavier · same face shrinkage
Woods of similar hardness
The eight nearest on the Janka scale, lbf.
Laboratory values
Its most unusual laboratory figure is stiffness (modulus of elasticity): 14th lowest of the 155 woods with a published value.
| Property | Green | Dry, 12% MC | Change when dried | Metric, 12% MC |
|---|---|---|---|---|
| Modulus of elasticity | 1.04M psi | 1.17M psi | +12% | 8.07GPa |
| Compression parallel to grain | 2,790psi | 4,800psi | +72% | 33.1MPa |
| Work to maximum load | 5.90in-lbf/in³ | 6.70in-lbf/in³ | +14% | 46.2kJ/m³ |
| Modulus of rupture | 6,300psi | 8,700psi | +38% | 60MPa |
| Shear parallel to grain | 830psi | 1,080psi | +30% | 7.40MPa |
| Side hardness | 440lbf | 550lbf | +25% | 2,447N |
Wood Handbook Table 5-5b, Table 4-4. Data & method · Guides