Species data
American Elm
Ulmus americana - a hardwood from eastern and Midwestern North America. Also sold as white elm, soft elm, water elm.
Properties at a glance
| Janka hardness | 830 lbf |
| Stiffness (MOE) | 1,340,000 psi |
| Specific gravity | 0.56 |
| Density | 34.9 lb/ft3 (560 kg/m3) |
| Weight per board foot | 2.91 lb |
| Shrinkage, green to oven-dry | 9.5% tangential / 4.2% radial |
| Indicative price | $4.00 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 American Elm compares
Measured against the 113 solid woods in this database: it is harder than 36% of them, heavier than 38%, and stiffer than 21%.
What that means in the shop
A 4/4 board 8 inches wide and 8 feet long is 5.33 board feet, so in American Elm it weighs about 15.5 lb. A stack of ten is 155 lb - worth knowing before you load a rack or a car.
Against red oak, the trade's usual yardstick at 1,220 lbf, American Elm is about 68% as hard and 80% as heavy.
Its shrinkage is 9.5% tangential against 4.2% radial, a ratio of 2.3 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 sits in that range.
Woods of similar hardness
Closest to American Elm on hardness in this database: Western Larch (830 lbf), African Mahogany (850 lbf), Bigleaf Maple (850 lbf), Black Ash (850 lbf). Similar hardness does not mean similar behaviour - check density and movement before substituting one for another.
Working with it
Workability. Interlocked grain causes tearout that complicates machining; stains, finishes, glues and steam-bends well
Durability. Non-durable; offers little defense, and insects attack it readily
Typical uses. furniture, boxes, baskets, hockey sticks, veneer.
Related calculators
Sources
MOE, SG (12% MC), Janka and shrinkage from The Wood Database (cites USDA FPL Wood Handbook). Uses, region, durability and workability summarized from The Wood Database. American Elm is not listed in the FPL/Hoadley dimensional change coefficient table, so CT/CR are omitted. 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.