battened plywood cases
1988 Edition

As per IS 2674 (1988), plywood used for cases must comply with Type AB, Grade MR or BWR according to IS 303:1989, with the grade mutually agreed upon by buyer and supplier. Timber for battens should belong to Group I or II species as defined in IS 6662:1980. Group III species are acceptable only if batten dimensions are increased by 3 mm thickness or 5 mm width. Group IV timber is prohibited for battens, and all other timbers require purchaser approval. Nails must be clout nails with a minimum shank diameter of 2.00 mm and length at least equal to the sum of plywood and batten thickness plus 5 mm, with clinched ends if protruding.

IS 2674 categorizes loads into three types based on density, fragility, and support characteristics: Easy loads are low to moderate density items that fully support the case faces and require lighter battens; Average loads have moderate density, providing partial support and needing medium-strength battens; Difficult loads include concentrated forces or delicate items that do not support case faces and necessitate heavy-duty battens with additional internal bracing and bolting. This classification determines the plywood thickness, batten size, and reinforcement needed to ensure safe handling and transport.

According to IS 2674 Clause 4.3 and related tables, plywood case styles and thicknesses are selected based on the mass of the contents and load category. For loads up to 25 kg, styles 1 and 2 with 4 mm plywood and 40x12 mm battens are recommended. For 26 to 50 kg, styles 2, 3, and 4 use 4 mm plywood for easy/average and 8 mm for difficult loads with 40x15 mm battens. Loads of 51 to 100 kg utilize styles 3, 4, and 5 with 4 or 5 mm plywood and 50x20 mm battens. For 101 to 150 kg, styles 4, 5, and 6 with 6 mm plywood and 60x20 mm battens are used. Finally, 151 to 250 kg loads use styles 6 and 7 with plywood thickness between 6 to 9 mm and 75x25 mm battens. Case length must not exceed 2.5 times the width or depth, and nail or staple spacing varies with load and mass as per the standard.

IS 2674 mandates the use of clout nails having a minimum shank diameter of 2.00 mm and length not less than the combined thickness of plywood and batten plus 5 mm. Nail sizes vary depending on batten dimensions, e.g., 40x12 mm battens use 40 mm nails with 2.00 mm diameter. Nails must be driven flush without over-penetration and clinched if protruding. Staples must be made of steel wire with at least 0.90 mm diameter, and the crown length must exceed the combined thickness of plywood and batten by at least 3 mm. Nail and staple spacing is prescribed based on load type and mass to ensure structural integrity.

Per IS 2674 Clauses 6.2 and 6.2.1, unassembled plywood case components must be securely bundled using string or iron hoops to ensure safe transportation. Each bundle should contain only one type of part, such as all sides or all ends. The weight of each bundle must not exceed 40 kg to facilitate safe handling. This bundling approach helps maintain component integrity and simplifies logistics.