Studies on Variation of Strength Properties in Wood

Variation from pith to periphery in specific gravity, fibre stress at elastic limit, modulus of rupture, modulus of elasticity and maximum crushing stress (Compression Parallel to grain) for the species Cedrus deodara (deodar), Dipterocarpus grandiflorus (gurjan), Machilus macrantha (Machilus), Pinus roxburghii (chir), Shorea robusta (sal) and Tectona grandis (teak) were studied. In general it was found that in conformity with other workers the strength increases with distance from the pith but near the periphery it again decreases. However there were certain exceptions. Variations in strength of the material due to North, East, South and West directions were also studied but no significant differences were observed.