Hackberry (Celtis occidentalis) in numbers: hardness, weight, strength, shrinkage, movement and decay resistance, taken from the tables of the USDA Forest Products Laboratory’s Wood Handbook, followed by what the wood is like to work and what it is used for. The values are averages from small, clear, straight-grained test specimens; real boards with knots, sloping grain or a different moisture content will differ.
| Property | Hackberry |
|---|---|
| Janka side hardness, 12% moisture | 880 lbf (3,914 N) |
| Janka side hardness, green | 700 lbf |
| Hardness rank | harder than 79 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 37.1 lb/ft³ (594 kg/m³) |
| Weight per board foot (12%) | 3.09 lb |
| Specific gravity (ovendry weight, green volume) | 0.49 |
| Specific gravity at 12% moisture | 0.53 |
| Bending strength (modulus of rupture), 12% | 11,000 psi |
| Stiffness (modulus of elasticity), 12% | 1.19 million psi |
| Crushing strength (compression parallel to grain), 12% | 5,440 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 4.8% / 8.9% / 13.8% |
| Tangential / radial shrinkage ratio | 1.85 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00165 / 0.00315 |
| Impact bending (drop height to failure), 12% | 43 in. |
| Heartwood decay resistance | slightly or nonresistant |
What it is
The lumber sold as hackberry comes from two trees: hackberry (Celtis occidentalis) and sugarberry (C. laevigata). Hackberry grows east of the Great Plains from Alabama, Georgia, Arkansas and Oklahoma northward, except along the Canadian boundary. Sugarberry overlaps the southern part of that range and grows throughout the Southern and South Atlantic States.
The sapwood of both species varies from pale yellow to greenish or grayish yellow, and the heartwood is commonly darker. The wood resembles elm in structure.
Working properties
Hackberry lumber is moderately heavy. It is moderately strong in bending, moderately weak in compression parallel to the grain, moderately hard to very hard and high in shock resistance, but low in stiffness. It has high shrinkage (8.9% tangentially from green to ovendry) but keeps its shape well during drying.
Weight and density
At 12% moisture content hackberry weighs about 37.1 lb per cubic foot, so one board foot (144 cubic inches) weighs about 3.09 lb. An 8 ft board of actual size 3/4 × 5-1/2 in. (a 1×6) holds 0.229 cubic feet and weighs about 8.5 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 10.8 lb. Green wood is much heavier because of the water it holds.
Density here is ovendry weight plus 12% water, divided by volume at 12% moisture content (Wood Handbook Eq. 4-12: density = specific gravity at 12% × 62.43 lb/ft³ × 1.12).
Wood movement
The Wood Handbook gives dimensional change coefficients for each species: the fraction of its width a board gains or loses for every 1% change in moisture content, between about 6% and 14%. For hackberry they are 0.00315 across a flatsawn face (tangential) and 0.00165 across a quartersawn face (radial).
Worked example: a flatsawn board 7-1/4 in. wide (a nominal 1×8) that goes from 6% moisture content in a heated winter house to 12% in a humid summer changes width by 7.25 × 0.00315 × 6 = 0.137 in. (about 1/8 in.). The same board quartersawn moves 0.072 in. (about 1/16 in.). Allow for this in panels, tabletops and floors; the wood movement calculator works it out for any size and moisture range.
How it compares
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Tangential shrink (%) | Decay resistance |
|---|---|---|---|---|---|---|
| Hackberry | 880 | 37.1 | 11,000 | 1.19 | 8.9 | slightly or nonresistant |
| American elm | 830 | 35.0 | 11,800 | 1.34 | 9.5 | slightly or nonresistant |
| White ash | 1,320 | 42.0 | 15,000 | 1.74 | 7.8 | slightly or nonresistant |
| Northern red oak | 1,290 | 44.1 | 14,300 | 1.82 | 8.6 | slightly or nonresistant |
| Red maple | 950 | 37.8 | 13,400 | 1.64 | 8.2 | slightly or nonresistant |
| Sweetgum | 850 | 36.4 | 12,500 | 1.64 | 10.2 | slightly or nonresistant |
Uses
Most hackberry is cut into lumber; small amounts are used for furniture parts, dimension stock and veneer.
Frequently asked questions
How hard is hackberry?
Hackberry averages 880 lbf (3,914 N) on the Janka test at 12% moisture content and 700 lbf green, a little softer than red maple (950 lbf).
Is hackberry like elm?
The Wood Handbook says hackberry resembles elm in structure, and in the tables it is close to American elm in hardness and weight (see the comparison table).
Does hackberry warp when it dries?
It shrinks a lot, 8.9% tangentially from green to ovendry, but the Handbook says it keeps its shape well during drying. In service a flatsawn board changes width by about 0.315% for each 1% change in moisture content.
Can hackberry be used outdoors?
Not untreated. Its heartwood is in the slightly or nonresistant decay class, so it needs preservative treatment or a protected location outdoors.
Sources
- USDA Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material. General Technical Report FPL-GTR-190, 2010. Chapter 2 (species descriptions), Chapter 4 (Tables 4-3, 4-4 shrinkage; Eq. 4-7, 4-9, 4-12 density), Chapter 5 (Tables 5-3b, 5-5b strength and hardness), Chapter 13 (Table 13-5 dimensional change coefficients), Chapter 14 (Table 14-1 decay resistance)
- USDA Forest Products Laboratory. Wood Handbook, 2021 edition (FPL-GTR-282)
Last reviewed: 24 October 2026. Numbers are generated from our parsed copy of the Handbook tables, so every page uses the same data. Values marked * are estimates computed with the Handbook’s own equations. Spotted an error? Please let us know.