Size Factor

Stresses parallel to grain for visually graded dimension lumber should be multiplied by the size factors provided in Tables 3.3a and 3.4a.

Size Factor

Compression Parallel to Grain

 

Size Factor

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Compression, T*nslon;and Shear Caused by Benohng

 

Size Factor

Tension

Parallel to Grain

 

Size Factor

Tension

Perpendicular to Gram

 

Size Factor

Figure 3.4 Forces and directions of grains.

 

When the depth d of the beam, stringer, post, or timber ex­ceeds 12 in., the tabulated design value Fb shall be multiplied by the following size factor:

 

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1/9

 

12.0

d

 

Cf =