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Ulmus spp. |
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Family: Ulmaceae |
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Elm |
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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
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.
The Wood
General
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.
Mechanical
Properties (2-inch standard)
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Compression |
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Specific gravity |
MOE X106 lbf/in2 |
MOR lbf/in2 |
Parallel lbf/in2 |
Perpendicular lbf/in2 |
WMLa in-lbf/in3 |
Hardness lbf |
Shear lbf/in2 |
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Ulmus alata (winged elm) |
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Green |
0.60 |
1.21 |
9,200 |
3,700 |
630 |
21.7 |
1,1140 |
1,30 |
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Dry |
0.66 |
1.65 |
14,800 |
6,780 |
1,020 |
23.1 |
1,540 |
2,370 |
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Ulmus americana (American elm) |
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Green |
0.46 |
1.11 |
7,200 |
2,910 |
360 |
11.8 |
620 |
1,000 |
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Dry |
0.50 |
1.34 |
11,800 |
5,520 |
690 |
13.0 |
830 |
1,510 |
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Ulmus crassifolia (cedar elm) |
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Green |
0.59 |
1.17 |
9,200 |
3,370 |
600 |
20.0 |
1,100 |
1,320 |
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Dry |
0.64 |
1.48 |
13,500 |
6,020 |
950 |
18.6 |
1,320 |
2,240 |
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Ulmus rubra (slippery elm) |
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Green |
0.48 |
1.23 |
8,000 |
3,320 |
420 |
15.4 |
660 |
1,110 |
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Dry |
0.53 |
1.49 |
13,000 |
6,360 |
820 |
16.9 |
860 |
1,630 |
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Ulmus thomasii (rock elm) |
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Green |
0.57 |
1.19 |
9,500 |
3,780 |
610 |
19.8 |
940 |
1,270 |
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Dry |
0.63 |
1.54 |
14,800 |
7,050 |
1,230 |
19.2 |
1,320 |
1,920 |
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aWML = Work to maximum load.
bReference (90). cReference (98). |
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Drying and
Shrinkage
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Type of shrinkage |
Percentage of
shrinkage |
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0% MC |
6% MC |
20% MC |
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Ulmus alata (winged elm) |
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Tangential |
11.6 |
— |
— |
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Radial |
5.3 |
— |
— |
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Volumetric |
17.7 |
— |
— |
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Ulmus americana (American elm) |
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Tangential |
9.5 |
7.6 |
3.2 |
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Radial |
4.2 |
3.4 |
1.4 |
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Volumetric |
14.6 |
11.7 |
4.9 |
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Ulmus crassifolia (cedar elm) |
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Tangential |
10.2 |
— |
— |
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Radial |
4.7 |
— |
— |
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Volumetric |
15.4 |
— |
— |
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Ulmus rubra (slippery elm) |
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Tangential |
8.9 |
7.1 |
3.0 |
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Radial |
4.9 |
3.9 |
1.6 |
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Volumetric |
13.8 |
11.0 |
4.6 |
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Ulmus thomasii (rock elm) |
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Tangential |
8.1 |
6.5 |
2.7 |
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Radial |
4.8 |
3.8 |
1.6 |
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Volumetric |
14.9 |
11.3 |
4.7 |
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References: 0% MC (98), |
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Kiln Drying
Schedulesa
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Stock |
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Condition |
4/4, 5/4, 6/4 |
8/4 |
10/4 |
12/4 |
16/4 |
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Standard |
T6-B3 |
T3-B2 |
T3-B2 |
T3-B1 |
T3-A1 |
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aReferences
(6, 86). |
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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 and References Cited (in parentheses)
6.?Boone,
R.S.; Kozlik, C.J.; Bois, P.J.; Wengert, E.M. 1988. Dry kiln schedules for
commercial woods-temperate
and tropical. Gen. Tech. Rep. FPL-GTR-57. Madison, WI: U.S.
Department of Agriculture, Forest Service, Forest Products Laboratory.
16.?Chen,
Y.S.; Schlesinger, R.C. 1973. Elm, an American wood. FS-233.
Washington, DC: U.S. Department of Agriculture, Forest Service.
29.?Elias,
T.S. 1980. The complete trees of North America, field guide and natural
history. New York: van Nostrand Reinhold Company.
55.
?Little, Jr., E.L. 1979. Checklist of United States trees (native and
naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of
Agriculture, Forest Service. U.S. Government Printing Office.
59.
Markwardt, L.J.; Wilson, T.R.C. 1935. Strength and related properties of woods
grown in the United States. Tech. Bull. 479. Washington, DC: U.S. Department of
Agriculture, Forest Service. U.S. Government Printing Office.
68.
Panshin, A.J.; de Zeeuw, C. 1980. Textbook of wood technology, 4th ed. New
York: McGraw—Hill Book Co..
74.
Record, S.J.; Hess R.W. 1943. Timbers of the new world. New Haven, CT: Yale
University Press.
86.
Simpson, W.T. 1991. Dry kiln operator's manual. Ag. Handb. 188. Madison, WI:
U.S. Department of Agriculture, Forest Service, Forest Products Laboratory.
90.
Summitt, R.; Sliker, A. 1980. CRC handbook of materials science. Boca Raton, FL:
CRC Press, Inc. Vol. 4.
98.
U.S. Department of Agriculture. 1987. Wood handbook: wood as an engineering
material. Agric. Handb. 72. (Rev.) Washington, DC: U.S. Department of
Agriculture. 466 p.