24. Mechanical Properties and Wood Drying Behaviour of Dalbergia sissoo

Dalbergia sissoo is an important Indian handicrafts timber species with a hard, moderately heavy heartwood ranging from golden brown to deep brown with distinct yellowish-white sapwood. When the comparative suitability index of the wood in terms of teak is taken as 100; D. sissoo outpaces even teak wood in certain properties like shock resistance ability, surface hardness, nail and screw holding property, and is near to teak in properties like strength as beam, suitability as posts, etc. The species wood strength properties like modulus of elasticity (MOE) values (6549 to 11,790 MPa), compressive strength (29,616–69,000 kPa in parallel to grain and 6668–14,824 kPa in perpendicular to grain), shear strength (9756–15,099 kPa in radial and 9894–13,858 kPa tangential directions), average tensile strength in perpendicular to grain (5394–9032 kPa and 4792–9135 kPa in radial and tangential directions), and hardness (5916–8118 kPa in radial, 6050–8874 kPa in tangential directions) show the uniqueness of the timber which makes it suitable for various end uses. Relatively lower fibre saturation point (FSP), equilibrium moisture content (EMC), volumetric shrinkage, etc. make this wood dimensionally stable and suitable for high-quality handicrafts. The wood can be satisfactorily dried using kiln drying schedule No. IV using a steam-heated kiln. Wood can also be dried using solar kilns and dehumidification kilns. This chapter discusses the mechanical and drying properties of Dalbergia sissoo wood in detail.