Common Name(s): Rock Elm, Cork Elm
Scientific Name: Ulmus thomasii
Distribution: Midwestern United States
Tree Size: 65-100 ft (20-30 m) tall, 2-4 ft (.6-1.2 m) trunk diameter
Average Dried Weight: 47 lbs/ft3 (755 kg/m3)
Specific Gravity (Basic, 12% MC): .57, .75
Janka Hardness: 1,320 lbf (5,870 N)
Modulus of Rupture: 14,800 lbf/in2 (102.1 MPa)
Elastic Modulus: 1,540,000 lbf/in2 (10.62 GPa)
Crushing Strength: 7,050 lbf/in2 (48.6 MPa)
Shrinkage: Radial: 4.8%, Tangential: 8.1%, Volumetric: 14.9%, T/R Ratio: 1.7
Color/Appearance: Heartwood is light to medium reddish brown. Paler sapwood is usually well defined.
Grain/Texture: Grain is interlocked (making it very resistant to splitting). With a somewhat coarse, uneven texture.
Rot Resistance: Rated as non-durable; susceptible to insect attack. Living trees are susceptible to Dutch elm disease.
Workability: Can be a challenge to work because of interlocked grain, especially on quartersawn surfaces. Planing can cause tearout and/or fuzzy surfaces. Poor dimensional stability. Glues, stains, and finishes well. Responds well to steam bending, and holds nails and screws well.
Odor: Elm usually has a strong, unpleasant smell when green; though once dried has very little odor.
Allergies/Toxicity: Although severe reactions are quite uncommon, Elm in the Ulmus genus has been reported as a sensitizer. Usually most common reactions simply include eye and skin irritation. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.
Pricing/Availability: Should be moderately priced, though availability from mature trees has been greatly diminished by Dutch elm disease.
Sustainability: This wood species is not listed in the CITES Appendices or on the IUCN Red List of Threatened Species.
Common Uses: Boxes, baskets, furniture, hockey sticks, veneer, wood pulp, and papermaking.
Comments: Elm trees are commonly infected with Dutch elm disease, a fungal disease spread by elm bark beetles. D.E.D. has wiped out millions of Elm trees worldwide.
- American Elm (Ulmus americana)
- Carpathian Elm (Ulmus procera)
- Cedar Elm (Ulmus crassifolia)
- Dutch Elm (Ulmus x hollandica)
- English Elm (Ulmus procera)
- Red Elm (Ulmus rubra)
- Winged Elm (Ulmus alata)
- Wych Elm (Ulmus glabra)