YOUNG'S MODULUS (MODULUS OF ELASTICITY) OF WOOD


Average Young's modulus values of wood along the longitudinal axis (EL) obtained from bending tests are given in the following table. 


Young's Modulus of Wood

Young's Modulus of Woods Along the Longitudinal Axis
Kind of Wood Moisture content Young's Modulus
(Modulus of Elasticity)
MPa 106 psi
Hardwoods
Alder, red Green 8100 1.17
12% 9500 1.38
Ash, white Green 9900 1.44
12% 12000 1.74
Basswood, American Green 7200 1.04
12% 10100 1.46
Beech, American Green 9500 1.38
12% 11900 1.72
Birch, yellow Green 10300 1.50
12% 13900 2.01
Cherry, black Green 9000 1.31
12% 10300 1.49
Cottonwood, eastern Green 7000 1.01
12% 9400 1.37
Elm, American Green 7700 1.11
12% 9200 1.34
Elm, rock Green 8200 1.19
12% 10600 1.54
True Hickory, shagbark Green 10800 1.57
12% 14900 2.16
Maple, sugar Green 10700 1.55
12% 12600 1.83
Oak, red, northern Green 9300 1.35
12% 12500 1.82
Oak, white Green 8600 1.25
12% 12300 1.78
Sweetgum Green 8300 1.20
12% 11300 1.64
Tupelo, black Green 7100 1.03
12% 8300 1.20
Walnut, black Green 9800 1.42
12% 11600 1.68
Softwoods
Baldcypress Green 8100 1.18
12% 9900 1.44
Cedar, northern white Green 4400 0.64
12% 5500 0.80
Cedar, western red Green 6500 0.94
12% 7700 1.11
Douglas-fir, coast Green 10800 1.56
12% 13400 1.95
Douglas-fir, interior west Green 10400 1.51
12% 12600 1.83
Douglas-fir, interior north Green 9700 1.41
12% 12300 1.79
Douglas-fir, interior south Green 8000 1.16
12% 10300 1.49
Fir, balsam Green 8600 1.25
12% 10000 1.45
Hemlock, eastern Green 7400 1.07
12% 8300 1.20
Hemlock, mountain Green 7200 1.04
12% 9200 1.33
Hemlock, western Green 9000 1.31
12% 11300 1.63
Larch, western Green 10100 1.46
12% 12900 1.87
Pine, eastern white Green 6800 0.99
12% 8500 1.24
Pine, ponderosa Green 6900 1.00
12% 8900 1.29
Pine, red Green 8800 1.28
12% 11200 1.63
Pine, shortleaf Green 9600 1.39
12% 12100 1.75
Pine, Virginia Green 8400 1.22
12% 10500 1.52
Pine, western white Green 8200 1.19
12% 10100 1.46
Redwood, old-growth Green 8100 1.18
12% 9200 1.34
Redwood, young-growth Green 6600 0.96
12% 7600 1.10
Spruce, black Green 9500 1.38
12% 11100 1.61
Spruce, Engelmann Green 7100 1.03
12% 8900 1.30
Spruce, red Green 9200 1.33
12% 11400 1.66
Spruce, sitka Green 8500 1.23
12% 10800 1.57
Spruce, white Green 7900 1.14
12% 9600 1.43
Spruce, sitka Green 8500 1.23
12% 10800 1.57

Average coefficients of variation of EL is 22% based on results of bending tests of clear & green wood from approximately 50 species. Values for wood adjusted to 12% moisture content may be assumed to be approximately of the same magnitude.

Average values of elastic moduli along the tangential (ET) and radial (ER) axes of wood for samples from a few species are given in the following table as ratios with elastic moduli along the longitudinal (EL) axis. Since the modulus of elasticity values are determined from bending, the tabulated values given above includes an effect of shear deflection. EL values from bending can be increased by 10% to remove this effect approximately.

Elastic ratios for various woods at approximately 12% moisture content
Kind of Wood ET/EL ER/EL
Hardwoods
Ash, white 0.080 0.125
Basswood 0.027 0.066
Birch, yellow 0.050 0.078
Cherry, black 0.086 0.197
Cottonwood, eastern 0.047 0.083
Maple, sugar 0.065 0.132
Oak, red 0.082 0.154
Oak, white 0.072 0.163
Sweetgum 0.050 0.115
Walnut, black 0.056 0.106
Softwoods
Baldcypress 0.039 0.084
Cedar, northern white 0.081 0.183
Cedar, western red 0.055 0.081
Douglas-fir 0.050 0.068
Hemlock, western 0.031 0.058
Larch, western 0.065 0.079
Pine, ponderosa 0.083 0.122
Pine, red 0.044 0.088
Pine, western white 0.038 0.078
Redwood 0.089 0.087
Spruce, sitka 0.043 0.078
Spruce, Engelmann 0.059 0.128

Reference:

  • Wood Handbook: Wood as an Engineering Material. United States Department of Agriculture, Forest Service, Forest Products Laboratory, 2010.
  • Baumeister, Theodore, et al. Marks' Standard Handbook for Mechanical Engineers. McGraw-Hill, 2007.
  • Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H. Machinery's Handbook . 30th edition.  Industrial Press Inc., 2016.