Species data
African Blackwood
Dalbergia melanoxylon - a hardwood from dry savanna of central and southern Africa. Also sold as mpingo, grenadilla.
Properties at a glance
| Janka hardness | 3,670 lbf |
| Stiffness (MOE) | 2,603,000 psi |
| Specific gravity | 1.27 |
| Density | 79.2 lb/ft3 (1,270 kg/m3) |
| Weight per board foot | 6.60 lb |
| Shrinkage, green to oven-dry | 4.8% tangential / 2.9% radial |
| Indicative price | $100.00 per board foot (estimated) |
Values are at about 12% moisture content. Density is specific gravity times 62.4; a board foot is one twelfth of a cubic foot, so weight per board foot is that density divided by twelve. Anything marked estimated is our own figure, not a measured one.
How African Blackwood compares
Measured against the 113 solid woods in this database: it is harder than 99% of them, heavier than 100%, and stiffer than 92%. Hard enough to be tough on edges and on machinery. At this density a full sheet or a long board gets heavy fast; check the shelf-sag and weight tools before you size anything.
What that means in the shop
A 4/4 board 8 inches wide and 8 feet long is 5.33 board feet, so in African Blackwood it weighs about 35.2 lb. A stack of ten is 352 lb - worth knowing before you load a rack or a car.
Against red oak, the trade's usual yardstick at 1,220 lbf, African Blackwood is about 3.0x as hard and 1.81x as heavy.
Its shrinkage is 4.8% tangential against 2.9% radial, a ratio of 1.7 to 1. The wider that ratio, the more unevenly a flatsawn board moves across its width as humidity changes, and the more it wants to cup; anything near or above 2 to 1 is worth quartersawing or restraining for panels and wide tops. This one moves comparatively evenly.
Woods of similar hardness
Closest to African Blackwood on hardness in this database: Ipe (3,490 lbf), Cumaru (3,330 lbf), Pink Ivory (3,230 lbf), Massaranduba (3,130 lbf). Similar hardness does not mean similar behaviour - check density and movement before substituting one for another.
Working with it
Workability. Extremely hard on tools and tough to machine, but unrivaled for fine lathe turning
Durability. Very durable against decay yet only moderately able to resist insects and borers
Typical uses. musical instruments, inlay, carving, tool handles, turned objects.
Related calculators
Sources
MOE, SG (12% MC), Janka and shrinkage from The Wood Database (citing USDA FPL and related sources). This imported species is not listed in the FPL/Hoadley dimensional change coefficient table, so CT/CR and movement source are omitted. Uses, region, durability and workability summarized from The Wood Database. Price indicative.
These calculators are for planning and estimation. Engineering results (shelf sag, wood movement) use published average material properties; real boards vary by grade, grain, moisture and defects. Verify load-bearing designs with a professional.