Elm (Ulmus spp.) contains about 45 species native to Asia [11], Europe and the Mediterranean [6], South and Central America [7] and North America [7]. All species look alike microscopically. The word ulmus is the classical Latin name.
Soft Elms
Ulmus americana American elm, American soft elm, American weeping elm, American white elm, Florida elm, gray elm, gray hard elm, rock elm, springwood, soft elm, swamp elm, water elm, white elm
Ulmus rubra gray elm, Indian elm, it slips ooo-hoosk-ah, moose elm, red elm, red wooded elm, rock elm, slippery elm, soft elm, sweet elm
Hard Elms
Ulmus alata cork elm, mountain elm, red elm, southern elm, wahoo, wahoo elm, water elm, whahoo, winged elm, witch elm
Ulmus crassifolia American red elm, basket elm, cedar elm, red elm, rock elm, small leaved elm, southern rock elm, Texas elm, water elm
Ulmus serotina Red elm, September elm
Ulmus thomasii Canadian rock elm, cliff elm, cork elm, corkbark elm, corky elm, corky barked elm, hickory elm, northern cork elm, northern corkbark elm, rock elm, swamp elm, Thomas elm, wahoo, white elm, white corky elm
Distribution: The eastern to midwest United States.
The Tree: Elm trees can reach a height of 100 ft (30 m), with a diameter of 3 ft (1 m). They may be infected with the Dutch elm disease, caused by a fungus (Ceratocystis ulmi), especially in shade trees.
General Wood Characteristics: The sapwood of elm is nearly white, while the heartwood is light brown to brown with a reddish tinge. The wood has no characteristic odor or taste.
Weight
Weight
Species MC SG lb/ft3 kg/m3
Ulmus alata Green 0.60 60 960
(winged elm)a 12% 0.66 42 673
Ovendry 0.73 NA NA
Ulmus americana Green 0.46 54 865
(American elm)b 12% 0.50 35 561
Ovendry 0.55 NA NA
Ulmus crassifolia Green 0.59 59 945
(cedar elm)a 12% 0.64 41 657
Ovendry 0.70 NA NA
Ulmus rubra Green 0.48 56 897
(slippery elm)b 12% 0.53 37 593
Ovendry 0.57 NA NA
Ulmus thomasii Green 0.57 53 849
(rock elm)b 12% 0.63 44 705
Ovendry 0.66 NA NA
aReference (90).
bReferences: specific gravity, green and
12%, (98); specific gravity, ovendry (59);
weight, (59).
Mechanical propertiesa
Property Green Dry
Ulmus alata (winged elm)a
MOE 1.21 106 8.343 GPa 1.65 106 11.377 GPa
lbf/in2 lbf/in2
MOR 9.20 103 63.434 MPa 14.8 103 102.046 MPa
lbf/in2 lbf/in2
C| | 3.70 103 25.512 MPa 6.78 103 46.748 MPa
lbf/in2 lbf/in2
C 0.63 103 4.344 MPa 1.02 103 7.033 MPa
lbf/in2 lbf/in2
WML 21.7 149.622 23.1 159.275
in-lbf/in3 kJ/m3 in-lbf/in3 kJ/m3
1,1140lbf 5,070.72 N 1,540 lbf 6,849.92 N
Hardness
1.30 103 8.963 MPa 2.37 103 16.341 MPa
Shear| | lbf/in2 lbf/in2
Ulmus Americana (American elm)b
MOE 1.11 106 7.653 GPa 1.34 106 9.239 GPa
lbf/in2 lbf/in2
MOR 7.20 103 49.644 MPa 11.8 103 81.361 MPa
lbf/in2 lbf/in2
C| | 2.91 103 20.064 MPa 5.52 103 38.060 MPa
lbf/in2 lbf/in2
C 0.36 103 2.482 MPa 0.69 103 4.758 MPa
lbf/in2 lbf/in2
WML 11.8 81.361 13.0 89.635
in-lbf/in3 kJ/m3 in-lbf/in3 kJ/m3
620 lbf 2,757.76 N 830 lbf 3,691.84 N
Hardness
Shear| 1.00 103 6.895 MPa 1.51 103 10.411 MPa
| lbf/in2 lbf/in2
Ulmus crassifolia (cedar elm)a
MOE 1.17 106 8.067 GPa 1.48 106 10.205 GPa
lbf/in2 lbf/in2
MOR 9.20 103 63.434 MPa 13.5 103 93.083 MPa
lbf/in2 lbf/in2
C| | 3.37 103 23.236 MPa 6.02 103 41.508 MPa
lbf/in2 lbf/in2
C 0.60 103 4.137 MPa 0.95 103 6.550 MPa
lbf/in2 lbf/in2
WML 20.0 137.900 18.6 128.247
in-lbf/in3 kJ/m3 in-lbf/in3 kJ/m3
1,100 lbf 4,892.80 N 1,320 lbf 5,871.36 N
Hardness
Shear| 1.32 103 9.101 MPa 2.24 103 15.444 MPa
| lbf/in2 lbf/in2
Ulmus rubra (slippery elm)b
MOE 1.23 106 8.481 GPa 1.49 106 10.274 GPa
lbf/in2 lbf/in2
MOR 8.00 103 55.160 MPa 13.0 103 89.635 MPa
lbf/in2 lbf/in2
C| | 3.32 103 22.891 MPa 6.36 103 43.852 MPa
lbf/in2 lbf/in2
C 0.42 103 2.896 MPa 0.82 103 5.654 MPa
lbf/in2 lbf/in2
WML 15.4 106.183 16.9 116.526
in-lbf/in3 kJ/m3 in-lbf/in3 kJ/m3
660 lbf 2,935.68 N 860 lbf 3,825.28 N
Hardness
Shear| 1.11 103 7.653 MPa 1.63 103 11.238 MPa
| lbf/in2 lbf/in2
Ulmus thomasii (rock elm)b
MOE 1.19 106 8.205 GPa 1.54 106 10.618 GPa
lbf/in2 lbf/in2
MOR 9.50 103 65.503 MPa 14.8 103 102.046 MPa
lbf/in2 lbf/in2
C| | 3.78 103 26.063 MPa 7.05 103 48.610 MPa
lbf/in2 lbf/in2
C 0.61 103 4.206 MPa 1.23 103 8.481 MPa
lbf/in2 lbf/in2
WML 19.8 136.521 19.2 132.384
in-lbf/in3 kJ/m3 in-lbf/in3 kJ/m3
940 lbf 4,181.12 N 1,320 lbf 5,871.36 N
Hardness
Shear| 1.27 103 8.756 MPa 1.92 103 13.238 MPa
| lbf/in2 lbf/in2
aReference (90).
bReference (98).
Drying and shrinkagea
Percentage of shrinkage
(green to final
moisture content)
Type of shrinkage 0% MC 6% MC 20% MC
Tangential
Ulmus alata (winged elm) 11.6 NA NA
Ulmus americana 9.5 7.6 3.2
(American elm)
Ulmus crassifolia (cedar 10.2 NA NA
elm)
Ulmus rubra (slippery 8.9 7.1 3.0
elm)
Ulmus thomasii (rock 8.1 6.5 2.7
elm)
Radial
Ulmus alata (winged elm) 5.3 NA NA
Ulmus americana (American 4.2 3.4 1.4
elm)
Ulmus crassifolia (cedar 4.7 NA NA
elm)
Ulmus rubra (slippery 4.9 3.9 1.6
elm)
Ulmus thomasii (rock elm) 4.8 3.8 1.6
Volumetric
Ulmus alata (winged elm) 17.7 NA NA
Ulmus americana (American 14.6 11.7 4.9
elm)
Ulmus crassifolia (cedar 15.4 NA NA
elm)
Ulmus rubra (slippery 13.8 11.0 4.6
elm)
Ulmus thomasii (rock elm) 14.9 11.3 4.7
aReferences: 0% MC, (98); 6% and 20%, (90).
Kiln drying schedulea
4/4, 5/4, 8/4 10/4 12/4 16/4
Species 6/4 stock stock stock stock
stock
Standard T6-B3 T3-B2 T3-B2 T3-B1 T3-A1
aReferences (6, 86).
Working Properties: Elm is moderately heavy, hard and stiff, with excellent bending and shock resistance. It is difficult to split because of its interlocked grain.
Durability: Rated as slightly or nonresistant to heartwood decay.
Preservation: Slippery elm is classed as permeable to preservatives,
and rock elm,
resistant.
Uses: Boxes, baskets, crates, cheese boxes, slack cooperage, furniture, caskets, hockey sticks, veneer, pulp and paper manufacture.
Toxicity: No information available at this time.
Additional Reading: 16, 29, 55, 68, 74. 55, 66, 68, 74, 79. 28, 29, 42, 43, 44, 48, 50, 55, 56, 68, 72, 73, 74, 79, 92, 97, 102. 74, 75, 77, 99, 106. 101. 82, 104.