Black Ash wood movement, board-foot & weight calculator
- Janka
- 850lbf
- Density
- 34.2lb/ft³
- T/R ratio
- 1.6
- Spec. gravity
- 0.49
Black Ash is a North American hardwood. It has a Janka side hardness of 850 lbf, a specific gravity of 0.49, and an air-dry density near 34 lb/ft³ (548 kg/m³) (mechanical values at 12% moisture content). It shrinks 7.8% tangentially and 5% radially from green to oven-dry (T/R ratio 1.6), so a 12-inch flatsawn board moves about 0.19 in (≈ 3/16 in) across a 6-point moisture swing (about 6%→12% MC).
Compute Black Ash: movement, weight & board footage
Every number below is worked from Black Ash's own shrinkage and density figures, not looked up from a table — change the width, moisture swing, or board size in the calculators linked alongside.
Cross-grain movement by board width
| Board width | Flatsawn (tangential) | Quartersawn (radial) |
|---|---|---|
| 2″ | 0.031″ (≈ 1/32 in) | 0.02″ (≈ 1/32 in) |
| 3″ | 0.047″ (≈ 1/32 in) | 0.03″ (≈ 1/32 in) |
| 4″ | 0.062″ (≈ 1/16 in) | 0.04″ (≈ 1/32 in) |
| 6″ | 0.094″ (≈ 3/32 in) | 0.06″ (≈ 1/16 in) |
| 8″ | 0.125″ (≈ 1/8 in) | 0.08″ (≈ 3/32 in) |
| 10″ | 0.156″ (≈ 5/32 in) | 0.1″ (≈ 3/32 in) |
| 12″ | 0.187″ (≈ 3/16 in) | 0.12″ (≈ 1/8 in) |
| 16″ | 0.25″ (≈ 1/4 in) | 0.16″ (≈ 5/32 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with Black Ash. At a T/R ratio of 1.56, Black Ash is stable — it moves moderately more across the face than through the thickness — normal behaviour for a furniture hardwood, and predictable if boards are acclimatised before milling.
Board footage & weight, standard sizes
| Nominal size × length | Board feet | Weight |
|---|---|---|
| 1×4 × 8′ | 2.67 bd ft | 7.6 lb |
| 1×6 × 8′ | 4 bd ft | 11.4 lb |
| 1×8 × 8′ | 5.33 bd ft | 15.2 lb |
| 1×10 × 8′ | 6.67 bd ft | 19 lb |
| 1×12 × 8′ | 8 bd ft | 22.8 lb |
| 2×4 × 8′ | 5.33 bd ft | 15.2 lb |
| 2×6 × 8′ | 8 bd ft | 22.8 lb |
| 2×8 × 8′ | 10.67 bd ft | 30.4 lb |
Different length or size? Run the board foot calculator or the weight calculator, both preloaded with Black Ash.
Seasonal movement by city
| City | Driest month (EMC) | Most-humid month (EMC) | EMC swing | 12″ board movement |
|---|---|---|---|---|
| Phoenix, AZ | Jun · 4.4% | Dec · 9% | 4.6 pts | 0.144″ (≈ 5/32 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.087″ (≈ 3/32 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.069″ (≈ 1/16 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.041″ (≈ 1/32 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.078″ (≈ 1/16 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.153″ (≈ 5/32 in) |
Driven by Black Ash's tangential shrinkage of 7.8%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How Black Ash compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Hardness: at 850 lbf, Black Ash is harder than 44% of the 157 species with a Janka figure.
- Weight: at 34.2 lb/ft³ it is heavier than 40% of the 170 species measured — an 8-foot 1×6 board weighs about 11.4 lb.
- Stability: its T/R ratio of 1.56 is more even than 79% of the 196 species here — as humidity changes, 21% of them hold their shape more evenly.
See Black Ash plotted against every species we carry: the full Janka hardness chart and the full density chart .
Species with a similar working profile
Closest matches on hardness, weight and stability together — useful when Black Ash is unavailable or priced out.
- Coast Douglas-fir is a common substitute for Black Ash : 16% softer, about the same weight, and similarly stable in service.
- Eastern Redcedar is a common substitute for Black Ash : 24% softer, about the same weight, and similarly stable in service.
- American Sycamore is a common substitute for Black Ash : 9% softer, about the same weight, and similarly stable in service.
- Black Walnut is a common substitute for Black Ash : 19% harder, 12% heavier, and similarly stable in service.
| Species | Janka | Density | T/R |
|---|---|---|---|
| Coast Douglas-fir | 710 lbf | 33.5 | 1.58 |
| Eastern Redcedar | 650 lbf | 32.8 | 1.52 |
| American Sycamore | 770 lbf | 34.2 | 1.68 |
| Black Walnut | 1,010 lbf | 38.4 | 1.42 |
About Black Ash
The Wood Handbook describes Black Ash as part of the Ash (Black Ash Group); the account below is of that group, which Black Ash belongs to.
The black ash group includes black ash (Fraxinus nigra) and pumpkin ash (F. profunda). Black ash grows in the Northeast and Midwest, and pumpkin ash in the South. Due to the spread of the emerald ash borer, both species are considered critically endangered by the IUCN. In an effort to curtail the problem, widespread harvesting of both live and dead trees is ongoing. The heartwood of black ash is a darker brown than that of American white ash; the sapwood is light-colored or nearly white. The wood of the black ash group is lighter in weight (basic specific gravity of 0.45 to 0.48) than that of the white ash group (basic specific gravity greater than 0.50). Pumpkin ash, American white ash (F. americana), and green ash (F. pennsylvanica) that grow in southern river bottoms, especially in areas frequently flooded for long periods, produce buttresses that contain relatively lightweight and brash wood. Principal uses for the black ash group are decorative veneer, cabinets, millwork, furniture, cooperage, and crates.
Durability & sustainability
CITES status: not listed on any CITES Appendix — no international-trade restriction applies to Black Ash.
Properties
| Specific gravity | 0.49 |
|---|---|
| Janka hardness (side) | 850 lbf |
| Density (air-dry, 12% MC) | 34.2 lb/ft³ (548 kg/m³) ovendry-weight basis: 30.6 lb/ft³ |
| Weight per board foot (air-dry) | 2.85 lb |
| Radial shrinkage (green→oven-dry) | 5% |
| Tangential shrinkage (green→oven-dry) | 7.8% |
| Volumetric shrinkage (green→oven-dry) | 15.2% |
| T/R ratio (stability indicator) | 1.6 |
Shrinkage is total green-to-oven-dry (Table 4-3); strength values are at 12% MC. Full bases and the derivation formulas are on the methodology page.
Data: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), public domain.