This specification outlines the criteria for hot rolled steel bars and flats utilized in manufacturing volute, helical, and laminated springs for automotive suspension. The steel must conform to one of the five specified grades detailed in the standard. IS 8910:1978 lays down the general material supply requirements.

Steel should be manufactured using open-hearth, electric, or a combination of these processes. To ensure quality, for each size of finished steel product, the ingots, billets, or continuous cast billets must be sized to allow for a minimum reduction ratio of 16:1 from the minimum cross-sectional area of the ingot or continuous cast billets to the maximum cross-sectional area of the product. Steel meeting this standard must be supplied in accordance with specified modes of delivery. The material must be devoid of harmful defects such as pipe, heavy scale, rust, blisters, laminations, cracked edges and seams, and other rolling defects that may compromise spring durability.

TESTS

The subsequent test must be conducted for Steel For Volute, Helical and Laminated Springs.

• Chemical composition

• Hardenability

• Mechanical properties

• Freedom from defects

• Straightness

MARKING:

Marking and packaging procedures must adhere to Indian standards. Every bar should bear the manufacturer's name or trademark, grade, and a cast number or any other identification mark enabling traceability to its origin. Additionally, the standard mark (ISI Mark) may be applied to the material.

Manufacturers are required to acquire a BIS license from the Bureau of Indian Standards in order to utilize the standard mark (ISI Mark). The Bureau issues licenses following a thorough evaluation of manufacturing infrastructure, production processes, and quality control and testing capabilities conducted during an on-site visit to the manufacturing premises.

PROCESS FOR BIS ISI MARK CERTIFICATION