Charlotte Bat Company
...continuing the tradition.
Made in the U.S.A.
Compressive Stress Perpendicular to
Grain: Reported as stress at proportional limit. There is no clearly defined ultimate stress for this property.
Shear Strength Parallel to Grain: Ability to resist internal slipping of one part upon another along the grain. Values presented are average strength in radial and tangential shear planes.
Impact bending: In the impact bending test, a hammer of given weight is dropped upon a beam from successively increased heights until rupture occurs or the beam deflects 152 mm (6 in.) or more. The height of the maximum drop, or the drop that causes failure, is a comparative value that represents the ability of wood to absorb shocks that cause stresses beyond the proportional limit.
Tensile Strength Perpendicular to Grain: Resistance of wood to forces acting across the grain that tends to split a member. Values presented are the average of radial and tangential observations.
Hardness: Generally defined as resistance to indentation using a modified Janka hardness test, measured by the load required to embed an 11.28-mm (0.444-in.) ball to one-half its diameter. Values presented are the average of radial and tangential penetrations.
Tensile Strength Parallel to Grain: Maximum tensile stress sustained in direction parallel to grain. Relatively few data are available on the tensile strength of various species of clear wood parallel to grain. Table 4–7 lists average tensile strength values for a limited number of specimens of a few species. In the absence of sufficient tension test data, modulus of rupture values are sometimes substituted for tensile strength of small, clear, straight grained pieces of wood. The modulus of rupture is considered to be low or conservative estimates of tensile strength for clear specimens (this is not true for lumber).
Shear Strength Parallel to Grain: Ability to resist internal slipping of one part upon another along the grain. Values presented are average strength in radial and tangential shear planes.
Impact bending: In the impact bending test, a hammer of given weight is dropped upon a beam from successively increased heights until rupture occurs or the beam deflects 152 mm (6 in.) or more. The height of the maximum drop, or the drop that causes failure, is a comparative value that represents the ability of wood to absorb shocks that cause stresses beyond the proportional limit.
Tensile Strength Perpendicular to Grain: Resistance of wood to forces acting across the grain that tends to split a member. Values presented are the average of radial and tangential observations.
Hardness: Generally defined as resistance to indentation using a modified Janka hardness test, measured by the load required to embed an 11.28-mm (0.444-in.) ball to one-half its diameter. Values presented are the average of radial and tangential penetrations.
Tensile Strength Parallel to Grain: Maximum tensile stress sustained in direction parallel to grain. Relatively few data are available on the tensile strength of various species of clear wood parallel to grain. Table 4–7 lists average tensile strength values for a limited number of specimens of a few species. In the absence of sufficient tension test data, modulus of rupture values are sometimes substituted for tensile strength of small, clear, straight grained pieces of wood. The modulus of rupture is considered to be low or conservative estimates of tensile strength for clear specimens (this is not true for lumber).
Strength Properties
Common Properties
Mechanical properties most commonly measured and represented as “strength properties” for design include modulus of rupture in bending, maximum stress in compression parallel to grain, compressive stress perpendicular to grain, and shear strength parallel to grain.
Additional measurements are often made to evaluate work to maximum load in bending, impact bending strength, tensile strength perpendicular to grain, and hardness. These properties, grouped according to the broad forest tree categories of hardwood and softwood (not correlated with hardness or softness), are given in Tables 4–3 to 4–5 for many of the commercially important species. Average coefficients of variation for these properties from a limited sampling of specimens are reported in Table 4–6.
Modulus of Rupture: Reflects the maximum load carrying capacity of a member in bending and is proportional to maximum moment borne by the specimen. Modulus of rupture is an accepted criterion of strength, although it is not a true stress because the formula by which it is computed is valid only to the elastic limit.
Work to Maximum Load in Bending: Ability to absorb shock with some permanent deformation and more or less injury to a specimen. Work to maximum load is a measure of the combined strength and toughness of wood under bending stresses. Compressive strength parallel to grain: Maximum stress sustained by a compression parallel-to-grain specimen having a ratio of length to least dimension of less than 11.
Compressive Stress Perpendicular to Grain: Reported as stress at proportional limit. There is no clearly defined ultimate stress for this property.
Additional measurements are often made to evaluate work to maximum load in bending, impact bending strength, tensile strength perpendicular to grain, and hardness. These properties, grouped according to the broad forest tree categories of hardwood and softwood (not correlated with hardness or softness), are given in Tables 4–3 to 4–5 for many of the commercially important species. Average coefficients of variation for these properties from a limited sampling of specimens are reported in Table 4–6.
Modulus of Rupture: Reflects the maximum load carrying capacity of a member in bending and is proportional to maximum moment borne by the specimen. Modulus of rupture is an accepted criterion of strength, although it is not a true stress because the formula by which it is computed is valid only to the elastic limit.
Work to Maximum Load in Bending: Ability to absorb shock with some permanent deformation and more or less injury to a specimen. Work to maximum load is a measure of the combined strength and toughness of wood under bending stresses. Compressive strength parallel to grain: Maximum stress sustained by a compression parallel-to-grain specimen having a ratio of length to least dimension of less than 11.
Compressive Stress Perpendicular to Grain: Reported as stress at proportional limit. There is no clearly defined ultimate stress for this property.