IS 4621:1975 is the Indian Standard (BIS) for indicating bolts for use in public baths and lavatories. This standard lays down the requirements regarding materials, dimensions, manufacture, and finish for indicating bolts (showing 'VACANT' or 'ENGAGED') meant for use on the doors of public baths and lavatories.
Specification for indicating bolts for use in public baths and lavatories
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Primary Material (Brass) | Specifies brass conforming to IS 319 (e.g., Cu 56-60%, Pb 2-3.5%, Zn Remainder). | No specific composition; material must pass performance tests for strength and corrosion. | BS EN 16337:2013 |
| Durability (Cyclic Test) | Not specified. Compliance is based on material and dimensional checks. | Required. Classified by grades, e.g., Grade 3 = 50,000 cycles, Grade 4 = 100,000 cycles. | BS EN 16337:2013 |
| Corrosion Resistance | Specified by plating finish, e.g., Chromium plating to Service Grade No. 2 of IS 1068. | Performance-based. Classified by grades (1-5) based on hours in salt spray test (e.g., Grade 3 = 96 hours). | BS EN 16337:2013 (ref. EN 1670) |
| Bolt Throw (Projection) | Minimum 12 mm. | Minimum 10 mm (for a single throw latch/bolt). | BS EN 12209:2016 |
| Indicator Letter Height | Minimum 6 mm for 'VACANT' and 'ENGAGED'. | Not typically specified in modern performance standards; this is left to manufacturer design within the product's function. | BS EN 16337:2013 |
| Emergency Release | Design includes a slot for emergency opening, but no performance is specified. | Performance is specified, e.g., max operating force for emergency release device ≤ 80 N. | BS EN 16337:2013 |