Machine Stress Rated Lumber Producers Council

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The Six Engineering Characteristics of Wood

The Big E and the Five Little f ’s Download as PDF

Engineering TermMeaning
E (Modulus of Elasticity)How much this sample will deflect under a given load.
Fb (Extreme fiber stress before failure occurs)How much we can stress a member in bending before permanently rupturing fibers.
fcii (Compressive strength when loaded parallel to grain)How much load we can put on the member when loaded like this before rupturing fibers.
fv (Horizontal shear)How much load we can apply as shown before material will fail along the indicated failure plane.
ft (Tensile strength parallel to grain)How much tension we can put this member under before failure.
Fc (Compressive strength loaded perpendicular to grain)How much load we can apply in this manner before actual crushing.