The IS 5187:1972 standard outlines the specifications for flush bolts designed to secure doors and cupboard panels so they sit flush within their frames. It details the requirements for materials, dimensions, finishes, marking, and testing to guarantee consistent quality and functionality. This standard is crucial for manufacturers and users requiring dependable and standardized flush bolt hardware in construction.
Overview
The IS 5187:1972 standard outlines the specifications for flush bolts designed to secure doors and cupboard panels so they sit flush within their frames. It details the requirements for materials, dimensions, finishes, marking, and testing to guarantee consistent quality and functionality. This standard is crucial for manufacturers and users requiring dependable and standardized flush bolt hardware in construction.
Audience
Contents
Structure
Defines the coverage of flush bolts including dimensions, tolerances, workmanship, and compliance requirements. Emphasizes mutual agreement between manufacturer and purchaser on specific clauses and references IS 2:1960 for rounding test results.
Tables 2 and 3 illustrate dimensional tolerances for Type 1 and Type 2 flush bolts.
Details the acceptable materials for flush bolt components such as cast brass, cast and extruded aluminum alloys, and phosphor bronze or steel springs. Material specifications ensure robustness, corrosion resistance, and mechanical integrity.
Includes a flowchart mapping components to their respective IS grades.
Describes Type 1 and Type 2 flush bolts with their standard sizes and shapes, including face plate dimensions, throw distances, bolt diameters, lip extensions, and screw hole specifications, all in millimeters.
Notes on material usage and illustrative component diagrams are included.
Specifies the materials, dimensional tolerances, workmanship quality, surface finish requirements, and marking norms essential for producing flush bolts conforming to the standard.
Lists detailed measurements for flush bolts covering face plate size, bolt throw, diameter, lip extension, number and size of screw holes, and socket plate dimensions. Emphasizes the 45-degree taper on bolt tops for smooth operation.
Explains finishing processes including satin or bright polishing, nickel and chromium plating for brass bolts, copper oxidation, and anodizing for aluminum bolts, to enhance durability and appearance.
Describes marking requirements such as the optional ISI certification mark indicating compliance, manufacturer identification, and the importance of marking for traceability and quality assurance.
Outlines sampling sizes and acceptance criteria based on lot quantities, detailing permissible defective flush bolts, testing methods, and rounding off of results per IS 2-1960 for quality control.
Defines the conditions under which a batch of flush bolts is deemed conforming or non-conforming based on defect counts in sampled lots, with rejection and rework guidelines.
Summarizes dimension tables, material specifications, and sampling plans to assist manufacturers and inspectors in verifying compliance with IS 5187 requirements.
Frequently Asked
IS 5187 prescribes specific materials for flush bolt manufacturing as per Table 1, Clause 2.1. The body and plate components may be made from cast brass (Grade 3 per IS:292-1961), or cast/extruded aluminum alloys conforming to IS:617-1959 and IS:733-1967. Bolts can also be fabricated from cast brass, extruded brass (IS:319-1968), or extruded aluminum alloys (IS:733-1967). Springs should be phosphor bronze (PCuSn 4, IS:1385-1968) or steel strip (any grade per IS:2507-1965). Typically, a single material type is used throughout all components except springs. Brass bolts can be satin or bright polished, nickel or chromium plated as per IS:4827-1968, or copper oxidized per IS:1378-1967. Aluminum bolts require anodizing with a finish grade no less than AC 10 according to IS:1868-1968, ensuring durability, corrosion resistance, and smooth function.
IS 5187 specifies the dimensions for flush bolts in Tables 2 and 3 for Type 1 and Type 2 respectively, referenced in Clause 5.1 and illustrated in Figure 1. Key dimensions include face plate lengths (100, 150, 200 mm for Type 1; 100 to 300 mm for Type 2), face plate breadth of 20 mm minimum, thickness of 4 mm minimum, throw of bolt ranging 20-30 mm for Type 1 and 15 mm for Type 2, bolt diameter fixed at 8 ± 1 mm, and lip extension varying from 20 to 50 mm depending on type and size. Screw holes range from 2 to 5, sized for 6 mm wood screws. The socket plates have thicknesses and dimensions corresponding to these parameters, ensuring correct fit and function.
Flush bolts manufactured under IS 5187 must have suitable surface finishes to ensure longevity and aesthetics. Brass flush bolts can be satin or bright polished, or alternatively plated with nickel or chromium following IS 4827-1968 standards. Copper oxidized finishes per IS 1378-1967 are also permitted upon purchaser’s request. Aluminum flush bolts are required to be anodized with a minimum finish grade of AC 15 as per IS 1868-1968. All finishes must provide smooth operation and corrosion resistance. Additionally, each bolt should bear the manufacturer’s name or trademark for identification.
IS 5187 recommends that flush bolts may carry the ISI Certification Mark as per Clause 7.1.1, signifying that the product complies with Indian Standards under regulated inspection and quality control by the Bureau of Indian Standards. This mark assures buyers that the flush bolts undergo continuous conformity assessment during production and marketing. Bolts failing to meet dimensional or finish criteria should not bear this certification. The marked identification aids traceability and enforces quality assurance.
According to Clause 9.1 and Appendix A of IS 5187, sampling for quality control depends on the lot size. Sample sizes and permissible defective quantities are defined in Table 4: for lots up to 200 units, 15 samples with zero defects allowed; for 201-300 units, 20 samples with 1 defective allowed; for 301-500, 30 samples with 2 defective; for 501-800, 40 samples with 2 defective; and for lots above 800, 55 samples with up to 3 defective bolts permissible. Testing involves checking dimensions and finish per Clauses 5 and 6. Test results are rounded following IS 2-1960. Lots exceeding allowed defective counts must be rejected or reworked. This procedure ensures adherence to the standard while balancing inspection effort.
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