wooden packing cases
1988 Edition

Timber species used must adhere to Appendix A of IS 6662-1980, which categorizes timbers into Groups I through IV based on suitability. Battens should be selected from Groups I, II, or III, with Group IV timbers only permissible for battens if explicit purchaser approval is obtained. When Group IV timbers are used for shooks, battens must be from Group III. Ideally, a single timber species is used per case, or if multiple species are employed, they must be from the same group. Use of other timber species requires prior written consent from the purchaser to ensure adequate strength and durability.

Classes of packing cases (A, B, C) are determined by the thickness and width of boards and battens, with Class A having the thickest materials and Class C the thinnest. Styles range from 1 to 3(b), differing in battens arrangement such as vertical or horizontal placement. Selection depends on load characteristics including mass, fragility, and handling difficulty, categorized as easy, average, or difficult. Class selection aligns with load severity, while style choice corresponds to the required protection and handling conditions. Dimension tolerances are permitted within ±5 mm on internal measurements.

Boards and battens must adhere to a thickness tolerance of ±2 mm. They are required to have smooth, uniform surfaces with rectangular cross-sections and square-trimmed ends. The grain should be oriented along the longest dimension to enhance strength and stability. These criteria ensure consistent quality and reliable performance of the timber components used in packing case construction.

Nails should be steel wire with countersunk heads conforming to IS:723-1972, featuring a minimum shank diameter of 2.00 mm. Nail length must be at least the combined thickness of boards and battens plus 6 mm. For boards up to 100 mm wide, at least two nails are required, placed 25 mm from edges; wider boards require a minimum of three nails spaced no more than 75 mm apart. Nails should be staggered and evenly spaced. Battens at the bottom, top, sides, and ends must be properly positioned and nailed, with all nails firmly clinched to ensure structural integrity according to IS 1503.

Preservative treatment is not compulsory for every wooden packing case under IS 1503. Clause 8.1 specifies that shooks should be treated as necessary and as agreed between the manufacturer and purchaser. When applied, treatment should follow IS 401-1982 guidelines to protect timber against decay and insect damage. The need for preservation depends on the intended usage, environmental conditions, and mutual agreement, ensuring durability without imposing unnecessary treatment costs.