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Oak
Worldwide, the oaks (Quercus
spp.) consist of 275 to 500 species that can be separated into three
groups based on their microanatomy: the live or evergreen oak group, the
red oak group (Erythrobalanus), and the white oak group (Leucobalanus).
Species within each group look alike microscopically. The word quercus
is the classical Latin name of oaks, said to be derived from Celtic fine
and tree.
The commercial North American species are as
follows:
Red Oak Group (Erythrobalanus)
- Quercus coccinea-bastard oak, black
oak, buck oak, red oak, scarlet oak, Spanish oak, spotted
oak
- Quercus falcata-American red oak,
bottomland red oak, cherrybark oak, Elliott oak, red oak,
Spanish oak, southern red oak, swamp red oak, swamp
spanish oak, turkeyfoot oak, water oak
- Quercus kelloggii-black oak, California
black oak, Kellogg oak, mountain black oak
- Quercus laurifolia-Darlington oak,
diamond-leaf oak, laurel oak, laurel-leaf oak, swamp laurel
oak, water oak, obtusa oak
- Quercus nigra-American red oak,
blackjack, pin oak, possum oak, punk oak, red oak, spotted oak, water
oak
- Quercus nuttallii-nuttall oak,
pin oak, red oak, red river oak, striped oak
- Quercus palustris-pin oak,
red oak, Spanish oak, Spanish swamp oak, Spanish water oak, swamp oak,
swamp Spanish oak, water oak
- Quercus phellos-black oak, laurel
oak, peach oak, pin oak, red oak, swamp willow oak, water oak, willow
oak, willow swamp oak
- Quercus rubra-American red oak,
black oak, buck oak, Canadian red oak, common red oak, gray oak, eastern
red oak, leopard oak, Maine red oak, mountain red oak, northern red
oak, red oak, Spanish oak, spotted oak, southern red oak, swamp red
oak, water oak, West Virginia soft red oak
- Quercus shumardii-American red oak,
Schneck oak, Schneck red oak, shumard oak, Shumard red oak,
southern red oak, spotted bark, spotted oak, swamp red oak, Texas oak,
Texas red oak
- Quercus velutina-American red oak,
blackjack, black oak, dyer oak, jack oak, quercitron,
quercitron oak, redbush, red oak, smoothbark oak, spotted oak, tanbark
oak, yellowbark, yellow oak, yellowbark oak
White Oak Group (Leucobalanus)
- Quercus alba-American white oak,
Arizona oak, Arizona white oak, forked-leaf white oak, Louisiana white
oak, mantua oak, ridge white oak, stave oak, true white oak, West Virginia
soft white oak, white oak
- Quercus bicolor-blue oak, cherry
oak, curly swamp oak, swamp oak, swamp white oak,
white oak
- Quercus garryana-Brewer oak, Garry
oak, Oregon oak, Oregon white oak, Pacific post oak,
Pacific white oak, post oak, prairie oak, shin oak, western oak, western
white oak, white oak
- Quercus lyrata-American white oak, overcup
oak, swamp post oak, swamp white oak, water white oak
- Quercus macrocarpa-blue oak, bur
oak, burr oak, mossycup oak, mossy-overcup oak, overcup oak, scrub
oak, white oak, white mossycup oak, white overcup oak
- Quercus michauxii-American white
oak, basket oak, cow oak, swamp oak, swamp chestnut oak
- Quercus muehlenbergii-chestnut oak,
chinkapin oak, chinquapin oak, dwarf chestnut oak, dwarf
chinkapin, pin oak, rock oak, rock chestnut oak, running white oak, scrub
oak, shrub oak, white oak, yellow oak, yellow chestnut oak
- Quercus prinus-American white oak,
basket oak, chestnut oak, chestnut rock oak, chestnut swamp
oak, cow oak, mountain oak, rock oak, rock chestnut, rock chestnut oak,
swamp oak, tanbark oak, white oak, white chestnut oak
- Quercus stellata-American post oak,
barren white oak, bastard oak, bastard white oak, box oak, box white oak,
brash oak, Delta post oak, Durand oak, iron oak, pin oak post oak,
ridge oak, rough oak, rough white oak, southern oak, turkey oak, white box
oak, white oak
Live Oak Group
- Quercus virginiana-dwarf live oak,
encino, live oak, rolfs oak, scrub live oak,
Virginia live oak, Virginia oak
Distribution
Widely distributed throughout the United States.
The Tree
Oaks can reach a height of 125 ft (38 m), with
large diameters.
The Wood
General
The sapwood of oak is white to very light brown,
while the heartwood is light to dark brown in the white oak group and
reddish brown in the red oak group. Oak wood has a course texture; it is
heavy, straight-grained, hard, tough, very stiff, and strong. Fast-grown
oak, with wide rings, is stronger and heavier than slow-grown oak.
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
|
| Red
Oak Group |
| Quercus
coccinea (scarlet oak) |
| Green |
0.60 |
1.48 |
10,400 |
4,090 |
830 |
15.0 |
1,200 |
1,410 |
| Dry |
0.67 |
1.91 |
17,400 |
8,330 |
1,120 |
20.5 |
1,400 |
1,890 |
| Quercus
falcata (southern red oak) |
| Green |
0.71 |
1.14 |
6,900 |
3,030 |
550 |
8.0 |
860 |
930 |
| Dry |
0.52 |
1.49 |
10,900 |
6,090 |
870 |
9.4 |
1,060 |
1,390 |
| Quercus
falcata var. pagodifolia (cherrybark oak) |
| Green |
0.61 |
1.79 |
10,800 |
4,620 |
760 |
14.7 |
1,240 |
1,320 |
| Dry |
0.68 |
2.28 |
18,100 |
8,740 |
1,250 |
18.3 |
1,480 |
2,000 |
| Quercus
laurifolia (laurel oak) |
| Green |
0.56 |
1.39 |
7,900 |
3,170 |
570 |
11.2 |
1,000 |
1,180 |
| Dry |
0.63 |
1.69 |
12,600 |
6,980 |
1,060 |
11.8 |
1,210 |
1,830 |
| Quercus
nigra (water oak) |
| Green |
0.56 |
1.55 |
8,900 |
3,740 |
620 |
11.1 |
1,010 |
1,180 |
| Dry |
0.63 |
2.02 |
15,400 |
6,770 |
1,020 |
11.8 |
1,210 |
2,020 |
| Quercus
palustris (pin oak) |
| Green |
0.58 |
1.32 |
8,300 |
3,680 |
720 |
14.0 |
1,070 |
1,290 |
| Dry |
0.63 |
1.73 |
14,000 |
6,820 |
1,020 |
14,800 |
1,510 |
2,080 |
| Quercus
phellos (willow oak) |
| Green |
0.56 |
1.29 |
7,400 |
3,000 |
610 |
8.8 |
980 |
1,180 |
| Dry |
0.69 |
1.90 |
14,500 |
7,040 |
1,130 |
14.6 |
1,460 |
1,650 |
| Quercus
rubra (northern red oak) |
| Green |
0.56 |
1.35 |
8,300 |
3,440 |
610 |
13.2 |
1,000 |
1,210 |
| Dry |
0.63 |
1.82 |
14,300 |
6,760 |
1,010 |
14.5 |
1,290 |
1,780 |
| Quercus
velutina ( black oak) |
| Green |
0.56 |
1.18 |
8,200 |
3,470 |
710 |
12.2 |
1,060 |
1,200 |
| Dry |
0.61 |
1.64 |
13,900 |
6,520 |
930 |
13.7 |
1,210 |
1,910 |
Mechanical Properties-continued
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|
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|
Compression |
|
|
|
|
Specific
Gravity
|
MOE
X106 lbf/in2
|
MOR
lbf/in2
|
Parallel
lbf/in2
|
Perpendicular
lbf/in2
|
WMLa
in-lbf/in3
|
Hardness
lbf
|
Shear
lbf/in2
|
| White
Oak Group |
| Quercus
alba (white oak) |
| Green |
0.60 |
1.25 |
8,300 |
3,560 |
670 |
11.6 |
1,060 |
1,250 |
| Dry |
0.68 |
1.78 |
15,200 |
7,440 |
1,070 |
13.7 |
1,210 |
1,910 |
| Quercus
bicolor (swamp white oak) |
| Green |
0.64 |
1.59 |
9,900 |
4,360 |
760 |
14.5 |
1,160 |
1,300 |
| Dry |
0.72 |
2.05 |
17,700 |
8,600 |
1,190 |
14.8 |
1,360 |
2,000 |
| Quercus
garryana (Oregon white oak) |
| Green |
0.64 |
- |
- |
- |
- |
- |
- |
- |
| Dry |
0.72 |
- |
- |
- |
- |
- |
- |
- |
| Quercus
lyrata (overcup oak) |
| Green |
0.57 |
1.15 |
8,000 |
3,370 |
540 |
12.6 |
960 |
1,320 |
| Dry |
0.63 |
1.42 |
12,600 |
6,200 |
810 |
15.7 |
1,190 |
2,000 |
| Quercus
macrocarpa (bur oak) |
| Green |
0.58 |
0.88 |
7,200 |
3,290 |
680 |
10.7 |
1,110 |
1,350 |
| Dry |
0.64 |
1.03 |
10,300 |
6,060 |
1,200 |
9.8 |
1,370 |
1,820 |
| Quercus
michauxii (swamp chestnut oak) |
| Green |
0.60 |
1.35 |
8,500 |
3,540 |
570 |
12.8 |
1,110 |
1,260 |
| Dry |
0.67 |
1.77 |
13,900 |
7,270 |
1,110 |
12.0 |
1,240 |
1,990 |
| Quercus
prinus (chestnut oak) |
| Green |
0.57 |
1.37 |
8,000 |
3,520 |
530 |
9.4 |
890 |
1,210 |
| Dry |
0.66 |
1.59 |
13,300 |
6,830 |
840 |
11.0 |
1,130 |
1,490 |
| Quercus
stellata (post oak) |
| Green |
0.60 |
1.09 |
8,100 |
3,480 |
860 |
11.0 |
1,130 |
1,280 |
| Dry |
0.67 |
1.51 |
13,200 |
6,600 |
1,430 |
13.2 |
1,360 |
1,840 |
| Live
Oak Group |
| Quercus
virginiana ( live oak) |
| Green |
0.80 |
1.58 |
11,900 |
5,430 |
2,040 |
12.3 |
- |
2,210 |
| Dry |
0.88 |
1.98 |
18,400 |
8,900 |
2,840 |
18.9 |
- |
2,660 |
aWML
= Work to maximum load.
Reference (59, 98).
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Drying and Shrinkage
| Type
of shrinkage |
Percentage
of shrinkage
(green to final moisture content) |
| 0%
MC |
6%
MC |
20%
MC |
| Red
Oak Group |
| Quercus
coccinea (scarlet oak) |
| Tangential |
10.8 |
7.8 |
3.2 |
| Radial |
4.4 |
3.7 |
1.5 |
| Volumetric |
14.7 |
11.0 |
4.6 |
| Quercus
falcata (southern red oak) |
| Tangential |
11.3 |
- |
- |
| Radial |
4.7 |
- |
- |
| Volumetric |
16.1 |
- |
- |
| Quercus
falcata var. pagodifolia (cherrybark oak) |
| Tangential |
10.6 |
- |
- |
| Radial |
5.5 |
- |
- |
| Volumetric |
16.1 |
- |
- |
| Quercus
laurifolia (laurel oak) |
| Tangential |
9.9 |
- |
- |
| Radial |
4.0 |
- |
- |
| Volumetric |
19.0 |
- |
- |
| Quercus
nigra (water oak) |
| Tangential |
9.8 |
7.4 |
3.1 |
| Radial |
4.4 |
3.4 |
1.4 |
| Volumetric |
16.1 |
13.1 |
5.5 |
| Quercus
palustris (pin oak) |
| Tangential |
9.5 |
7.6 |
3.2 |
| Radial |
4.3 |
3.4 |
1.4 |
| Volumetric |
14.5 |
11.6 |
4.8 |
| Quercus
phellos (willow oak) |
| Tangential |
9.6 |
- |
- |
| Radial |
5.0 |
- |
- |
| Volumetric |
18.9 |
- |
- |
| Quercus
rubra (northern red oak) |
| Tangential |
8.6 |
6.6 |
2.7 |
| Radial |
4.0 |
3.2 |
1.3 |
| Volumetric |
13.7 |
10.8 |
4.7 |
| Quercus
velutina ( black oak) |
| Tangential |
11.1 |
7.8 |
3.2 |
| Radial |
4.4 |
3.6 |
1.5 |
| Volumetric |
15.1 |
11.4 |
4.7 |
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Drying and Shrinkage-continued
| Type
of shrinkage |
Percentage
of shrinkage
(green to final moisture content) |
| 0%
MC |
6%
MC |
20%
MC |
| White
Oak Group |
| Quercus
alba (white oak) |
| Tangential |
10.5 |
7.2 |
3.0 |
| Radial |
5.6 |
4.2 |
1.8 |
| Volumetric |
16.3 |
12.6 |
5.3 |
| Quercus
bicolor (swamp white oak) |
| Tangential |
- |
- |
- |
| Radial |
- |
- |
- |
| Volumetric |
- |
- |
- |
| Quercus
garryana (Oregon white oak) |
| Tangential |
- |
- |
- |
| Radial |
- |
- |
- |
| Volumetric |
- |
- |
- |
| Quercus
lyrata (overcup oak) |
| Tangential |
12.7 |
- |
- |
| Radial |
5.3 |
- |
- |
| Volumetric |
16.0 |
- |
- |
| Quercus
macrocarpa (bur oak) |
| Tangential |
8.8 |
7.0 |
2.9 |
| Radial |
4.4 |
3.5 |
1.5 |
| Volumetric |
12.7 |
10.2 |
4.2 |
| Quercus
michauxii (swamp chestnut oak) |
| Tangential |
10.8 |
8.6 |
3.6 |
| Radial |
5.2 |
4.2 |
1.7 |
| Volumetric |
16.4 |
13.1 |
5.5 |
| Quercus
prinus (chestnut oak) |
| Tangential |
10.8 |
7.8 |
3.2 |
| Radial |
5.3 |
4.4 |
1.8 |
| Volumetric |
16.4 |
13.4 |
5.6 |
| Quercus
stellata (post oak) |
| Tangential |
9.8 |
7.8 |
3.3 |
| Radial |
5.4 |
4.3 |
1.8 |
| Volumetric |
16.2 |
13.0 |
5.4 |
| Live
Oak Group |
| Quercus
virginiana ( live oak) |
| Tangential |
9.5 |
7.6 |
3.2 |
| Radial |
6.6 |
5.3 |
2.2 |
| Volumetric |
14.7 |
13.0 |
5.4 |
References:
0% MC (98),
6% and 20% MC (90). |
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Kiln Drying Schedulesa
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Stock |
| Condition |
4/4,
5/4, 6/4 |
8/4 |
10/4 |
12/4 |
16/4 |
| Western
oaksb |
| Standard |
T3-B1 |
T3-B1 |
- |
- |
- |
| Upland
red oaksc |
| Standard |
T4-D2 |
T3-D1 |
T3-C1 |
T3-C1 |
|
| Lowland
red oaksd |
| Standard |
T2-C1 |
Table
113 |
- |
- |
- |
| Upland
white oakse |
| Standard |
T4-C2 |
T3-C1 |
T3-B1 |
T3-B1 |
- |
| Lowland
white oaksf |
| Standard |
T2-C1 |
Table
113 |
- |
- |
- |
aReferences
(6, 86).
b California
black, Oregon white, canyon live.
cBlack, blackjack,
cherrybark, northern pin, northern red, scarlet, Schumard,
southern red, turkey, water.
dCherrybark, laurel,
nuttall, pin, Shumard, water, willow.
eBlue, bur, chestnut,
chinkapin, Emory, Gambel, Mexican blue, post, white.
fBur, live, overcup, swamp chestnut, swamp white,
white.
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Working Properties: Oak wood has good working properties. It
machines and glues well and holds fasteners extremely well. It tends to
split when nailed, unless predrilled. Oak finishes well, but shrinks
considerably.
Durability:
The oaks are rated with respect to resistance to heartwood decay as
follows (98):
-
Very resistant--bur oak, chestnut oak, Gambel
oak, Oregon oak, post oak and white oak
-
Moderately resistant--swamp chestnut oak
-
Slightly to nonresistant--black oak and red oak
Preservation:
The heartwood of the white oak group is resistant to impregnation with
preservatives, whereas that of the red oak group is more easily
penetrated.
Uses: Ships,
railroad crossties, timber bridges, tannin dyes, fuel wood, hardwood
dimensions and flooring, furniture, veneer, plywood, barrels, kegs and
casks (white oak group), truck and trailer beds, mining timbers,
containers, pallets, caskets, boxes, paneling.
Toxicity: May
cause allergic bronchial asthma, rhinitis, and dermatitis (40, 64, 105).
Source: US Forest Service
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