TM 5-852-4/AFM 88-19, Chap. 4
Table 2-2. Specific Gravity and Strength of Wood43
Specific gravity of typical species at 12% moisture content are:
Ponderosa pine
0.40
Western hemlock
0.48
Loblolly pine
0.51
Eastern hemlock
0.41
Sitka spruce
0.40
Lodgepole pine
0.41
Douglas-fir, coast type
0.48
Englelmann spruce
0.34
White fir
0.37
Alaska cedar
0.44
(Forest Products Laboratory,
U.S. Department of Agriculture)
Specific Gravity-Strength Relation
Air-dry wood (12%
Green wood
moisture content)
Static bending:
Fiber stress at propor-
1.25
1.25
16,700G
tional limit, psi
10,200G
1.25
1.25
Modulus of rupture, psi
17,600G
25,700G
Work to maximum load,
3
1.75
1.75
35.6G
32.4G
in. lb/in.
3
2
2
Total work, in. lb/in.
103G
72.7G
Modulus of elasticity,
1000 psi
2,360G
2,800G
Impact bending, height of drop
1.75
1.75
94.6G
causing complete failure, in.
114G
Compression parallel to grain:
Fiber stress at proportional
limit, psi
5,250G
8,750G
Maximum crushing strength,
psi
6,730G
12,200G
Modulus of elasticity,
1000 psi
2,910G
3,380G
Compression perpendicular to
grain, fiber stress at propor-
2.25
2.25
4,630G
tional limit, psi
3,000G
2.25
2.25
End, lb
3,740G
4,800G
2.25
2.25
Side, lb
3,420G
3,770G
1.25
*The properties and values should be read as equations: for example, modulus of rupture for green wood = 17,600G
where G represents the specific gravity of oven-dry wood, based on the volume at the moisture condition indicated.
(Courtesy of Forest Products Laboratory USDA)
2-28
Previous Page
