Cocobolo wood movement calculator
- Janka
- —
- Density
- —
- T/R ratio
- 1.6
- Spec. gravity
- —
Cocobolo (Dalbergia retusa) is an imported species. The Wood Handbook strength tables list no matched specific gravity or hardness for it, so those fields are shown as “—”. It shrinks 4.3% tangentially and 2.7% radially from green to oven-dry (T/R ratio 1.6), so a 12-inch flatsawn board moves about 0.1 in (≈ 3/32 in) across a 6-point moisture swing (about 6%→12% MC).
Compute Cocobolo: movement, weight & board footage
Every number below is worked from Cocobolo'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″ | 0.017″ (≈ 1/32 in) | 0.011″ (≈ 0 in) |
| 3″ | 0.026″ (≈ 1/32 in) | 0.016″ (≈ 1/32 in) |
| 4″ | 0.034″ (≈ 1/32 in) | 0.022″ (≈ 1/32 in) |
| 6″ | 0.052″ (≈ 1/16 in) | 0.032″ (≈ 1/32 in) |
| 8″ | 0.069″ (≈ 1/16 in) | 0.043″ (≈ 1/32 in) |
| 10″ | 0.086″ (≈ 3/32 in) | 0.054″ (≈ 1/16 in) |
| 12″ | 0.103″ (≈ 3/32 in) | 0.065″ (≈ 1/16 in) |
| 16″ | 0.138″ (≈ 1/8 in) | 0.086″ (≈ 3/32 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with Cocobolo. At a T/R ratio of 1.59, Cocobolo 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 and weight aren't shown for Cocobolo — the Wood Handbook strength tables carry no matched density for it, so a weight figure here would be invented rather than computed. The board foot calculator still works without a species; board feet don't depend on density.
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 | 0.079″ (≈ 3/32 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.048″ (≈ 1/16 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.038″ (≈ 1/32 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.022″ (≈ 1/32 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.043″ (≈ 1/32 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.084″ (≈ 3/32 in) |
Driven by Cocobolo's tangential shrinkage of 4.3%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How Cocobolo compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Stability: its T/R ratio of 1.59 is more even than 73% of the 196 species here — as humidity changes, 27% of them hold their shape more evenly.
Durability & sustainability
CITES status: Cocobolo is listed on CITES Appendix II, which restricts international trade. Cocobolo (Dalbergia retusa) falls under the genus-wide Dalbergia CITES Appendix II listing (added 2017).
Properties
| Specific gravity | — |
|---|---|
| Janka hardness (side) | — |
| Density (air-dry, 12% MC) | — |
| Weight per board foot (air-dry) | — |
| Radial shrinkage (green→oven-dry) | 2.7% |
| Tangential shrinkage (green→oven-dry) | 4.3% |
| Volumetric shrinkage (green→oven-dry) | 7% |
| T/R ratio (stability indicator) | 1.6 |
Shrinkage is total green-to-oven-dry (Table 4-4); strength values are at 12% MC. Full bases and the derivation formulas are on the methodology page. Values shown as “—” have no matched entry in the Wood Handbook strength tables (5-3b/5-5b).
Data: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), public domain.