Wooden handles for hand hammers-
1989 Edition

IS 4953 references IS 620:1985 for timber specifications. Handles must be made from timber classified as Class 1, 2, or 3 depending on handle length. Class 1 includes hardwoods like Hickory, Ash, Shisham, and Teak, suitable for longer, heavy-duty handles. Class 2 covers species such as Sal, Mango, and Eucalyptus for medium-duty use. Class 3 involves other local hardwoods with moderate strength, appropriate for shorter or lighter handles. The wood must be straight-grained, free from defects like knots or cracks, and meet moisture content limits below 15% to ensure durability and safety.

According to IS 4953 Clause 5.1 and Table 1, handle lengths range from 300 mm to 900 mm depending on hammer type and weight. Dimensions labeled E, F, A, B, C, D, G, and H define the cross-sectional and grip sizes. For instance, an engineer's ball pein hammer weighing 100 g requires a handle 300 mm long with dimensions like E=10 mm, F=15 mm, A=15 mm, B=20 mm, C=10 mm, D=15 mm, G=57 mm, and H=57 mm. Larger hammers like double face sledges weighing 5-6 kg need handles about 900 mm in length with proportionally larger cross-sections. Tolerances are ±3 mm for dimensions A, B, E, and F, and ±2 mm for other dimensions to maintain quality and fit.

Post-manufacture, handles accepted after inspection should be immersed in hot raw linseed oil heated to approximately 90°C for one hour. After soaking, handles must be thoroughly drained and then wiped dry with a clean cloth. This treatment enhances resistance to moisture and wear, extending the handle's service life. Additionally, the wood should be air-seasoned to a moisture content not exceeding 15%, straight-grained with minimal defects, fulfilling the quality standards described in IS 620:1985 for workmanship and finishing.

IS 4953 ensures compatibility by explicitly referencing IS 841 (steel hammers) and IS 6546 (claw hammers) standards. It specifies handle dimensions corresponding to hammer types and nominal weights defined in these steel hammer standards, ensuring proper fit and ergonomic performance. Material quality requirements align with IS 620 for wooden handles, and terminology is consistent with IS 707. This harmonization facilitates interchangeability and safety between wooden handles and hammer heads specified in the related standards.

Quality control follows the sampling procedures and acceptance criteria outlined in IS 620:1985, which mandates representative sampling and testing to confirm dimensional and material compliance. Handles must meet specified moisture content and workmanship standards, be free from critical defects, and bear legible markings including the manufacturer's identity and year of production. The use of the BIS Standard Mark requires manufacturers to hold a license and submit to ongoing inspections by BIS to ensure consistent adherence to the standard and maintain product quality.