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Pinus jeffreyi |
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Family: Pinaceae |
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Jeffrey Pine |
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The genus Pinus is composed of about 100 species native
to temperate and tropical regions of the world. Wood of pine can be separated
microscopically into the white, red and yellow pine groups. The word pinus is the classical Latin name. The word jeffreyi is used in honor of the trees
discoverer, John Jeffrey (1826-1853), Scotch botanical explorer who collected
seeds and plants in Oregon and California (1850-1853) for introduction in
Scotland. Jeffrey pine was first classified as a variety of ponderosa pine, and
has identical wood properties of ponderosa pine.
Other Common Names: Blackbark pine, blackwood pine, bull
pine, Jeffrey pijn, Jeffrey pine, Jeffrey's pine, Jeffrey-tall, peninsula black
pine, peninsula pine, pin de Jeffrey, pino de Jeffrey, pino di Jeffrey, pino
negro, pinos, ponderosa pine, redbark pine, redbark sierra pine, sapwood pine,
truckee pine, western black pine, western yellow pine.
Distribution: Jeffrey pine is native to the mountains
of southwestern Oregon south in California through the Sierra Nevada to western
Nevada and to southern California. Also in northern Mexico.
The Tree: Jeffrey pine trees reach heights of 200
feet, with diameters of 6 feet. A survivor of early timber harvests was
measured at 175 feet tall and 7.5 feet in diameter. Jeffrey pines trees may
live to 500 years of age.
General Wood Characteristics: Jeffrey pine is identical to ponderosa
pine, with respect to its mechanical and physical properties. Both are in the
Yellow Pine Group. The following general information is for ponderosa pine. The
heartwood is yellowish to light reddish brown or orange and the wide sapwood is
nearly white to pale yellow. In young trees, the sapwood can make up over half
of the volume, while in older trees, the sapwood may be two inches or more
wide. The wood of the outer portions of saw timber size is moderately light in
weight, moderately low in strength, moderately soft, moderately stiff, and
moderately low in shock resistance. It is moderately weak in bending and in
endwise compression. It is straight grained (but can be dimpled on the
tangential surface) and has moderately small shrinkage. It is quite uniform in
texture and has little tendency to warp and twist.
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 |
Green |
0.37 |
.98 |
5000 |
2370 |
350 |
4.7 |
340 |
690 |
Dry |
0.42 |
1.24 |
9300 |
5530 |
790 |
6.6 |
500 |
1210 |
aWML = Work to maximum load.
Reference (153). |
Drying and Shrinkage
Type of shrinkage |
Percentage of
shrinkage |
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0% MC |
6% MC |
20% MC |
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Tangential |
6.7 |
5.0 |
2.1 |
Radial |
4.4 |
3.1 |
1.3 |
Volumetric |
9.9 |
7.7 |
3.2 |
References: (153, 192). |
Kiln Drying Schedulesa
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Conventional
temperature/moisture content-controlled schedulesa |
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4/4,
5/4 |
6/4
stock |
8/4 |
10/4 |
12/4 |
British
schedule |
Standard |
T9-C6 |
T7-C5 |
T7-C5 |
T7-A4 |
T7-A4 |
L |
Anti-brown stain |
T7-E6 |
NA |
T7-E5 |
NA |
NA |
NA |
aReference
(28, 185). |
Conventional
temperature/time-controlled schedulesa |
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Lower
grades |
Upper
grades |
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4/4,
5/4 stock |
6/4
stock |
8/4
stock |
4/4,
5/4 stock |
6/4
stock |
8/4
stock |
12/4,
16/4 stock |
Standard |
291 |
291 |
291 |
299 |
300 |
301 |
302 |
aReferences
(28, 185). |
High temperaturea |
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4/4,
5/4 stock |
6/4
stock |
8/4
stock |
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Standard |
400 |
400 |
400 |
NA |
aReferences
(28, 185). |
Working Properties: Jeffrey pine (ponderosa pine) works
easily with both hand and machine tools. It finishes and glues well, but the
presence of knots make painting difficult. It is resistant to splitting when
nailed, but is rated average in nail holding ability.
Durability: Jeffrey pine (ponderosa pine) is not
durable unless treated with a preservative, under conditions favorable to
decay. It is rated as slightly to nonresistant to decay. Can be susceptible to
attack by drywood termites, ambrosia (pinhole borer) beetles, longhorn beetles
and Buprestid beetles.
Preservation: Like ponderosa pine, the sapwood of
Jeffrey pine is permeable to preservatives, while the heartwood is moderately
resistant to preservative treatments.
Uses: Jeffrey pine (ponderosa pine) is used
mainly for lumber and to a lesser extent for piles, poles, posts, mine timbers,
veneer, and railroad crossties. The clear wood is especially well suited for
millwork, such as window frames, doors, shelving, moldings, sash doors, blinds,
paneling, mantels, trim, and built-in cases and cabinets. Lower grade lumber is
used for boxes and crates. Much of the lumber of intermediate or lower grades
goes into sheathing, subflooring, and roof boards. Knotty Jeffrey pine is used
for interior finish. A considerable amount now goes into particleboard and
paper.
Toxicity: In general, working with pine wood may
cause dermatitis, allergic bronchial asthma or rhinitis in some individuals
(4,9&12).
Additional Reading and
References Cited (in
parentheses)
1. Boone, R. S.;
Kozlik, C. J.; Bois, P. J., and Wengert, E. M. Dry kiln schedules for
commercial woods - temperate and tropical. Madison, WI: USDA Forest Service,
FPL-GTR-57; 1988.
2. Dallimore,
W.; Jackson, A. B., and Harrison, S. G. A handbook of Coniferae and
Ginkgoaceae. London, UK: Edward Arnold Ltd.; 1966.
3. Elias, T. S.
The complete trees of North America, field guide and natural history. New York,
NY: van Nostrand Reinhold Co.; 1980.
4. Hausen, B. M.
Woods injurious to human health. A manual. New York, NY: Walter de Gruyter;
1981.
5. Jenkinson, J.
L. Pinus
jeffrey
Grev. & Balf. Jeffrey Pine. in: Burns, R. M. and Honkala, B. H., tech.
coords. Silvics of North America. Volume 1, Conifers. Washington, DC: USDA
Forest Service; 1990; pp. 359-369.
6. Little, jr.
E. L. Checklist of United States trees (native and naturalized). Washington,
DC: USGPO, USDA Forest Service, Ag. Handbook No. 541; 1979.
7. Lowrey, D. P.
Ponderosa pine, an American wood. Washington, DC: USDA Forest Service, FS-254;
1984.
8. Markwardt, L.
J. and Wilson, T. R. C. Strength and related properties of woods grown in the
United States. Washington, DC: USGPO, USDA Forest Service, Tech. Bull. No. 479;
1935.
9. Mitchell, J.
and Rook, A. Botanical dermatology: plants and plant products injurious to the
skin. Vancouver, BC: Greenglass Ltd.; 1979.
10. Simpson, W.
T. Dry kiln operator's manual. Madison, WI: USDA Forest Service, FPL Ag.
Handbook No. 188; 1991.
11. Summitt, R.
and Sliker, A. CRC handbook of materials science. Vol. 4. Boca Raton, FL: CRC
Press, Inc.; 1980.
12. Woods, B.
and Calnan, C. D. Toxic woods. British Journal of Dermatology. 1976;
95(13):1-97.