This standard outlines the specifications for rolled structural steel plates, sections, flats, and bars utilized in ship hull construction. Grade I is designed for general purposes, while Grade II and Grade III serve special applications. It's important to note that this standard excludes rivet bars used in ship construction.

The steel must be produced utilizing methods such as open hearth, electric furnace, basic oxygen, or any other process approved by the purchaser. For steel produced by the basic oxygen process, the nitrogen content must not exceed 0.007 percent. Grade I steel may be either killed or semi-killed. Grade II steel must be of the killed type, incorporating fine grain practice and the application of aluminium or other grain refiners. Additionally, Grade II steel may be supplied in a semi-killed state for thicknesses up to and including 35 mm, provided that steel over 25 mm thickness undergoes normalization. Grade III steel should be provided in fully killed conditions, manufactured with fine grain practice, and incorporating aluminium and other grain refining elements like Nb, V, and Ti.

All materials must be devoid of cracks, surface flaws, segregation, lamination, pipe, and any other defects that could negatively impact the material's performance. Surface defects may be eliminated through chipping or grinding, ensuring that the material's thickness remains at least 93 percent of the nominal thickness, with no more than a 3 mm reduction at the dressed location.

TESTS

The subsequent test must be conducted for Structural Steel.

• Tensile test

• Impact test

• Chemical composition

• Tolerance

MARKING:

Each finalized product must bear the inspecting authority's brand in at least one area designated by the manufacturer. Unless specified otherwise, the following details must also be visibly marked on every product:

• Manufacturers name or trade mark

• Grade of steel

• Cast number

• Purchaser identification mark, if required by the purchaser.

Manufacturers have the option to apply the ISI mark to the material. However, to use the standard mark (ISI Mark), they must first obtain a BIS license from the Bureau of Indian Standards. This license is awarded after a thorough assessment of manufacturing infrastructure, production processes, and quality control and testing capabilities during an inspection conducted at the manufacturing premises by the Bureau.

PROCESS FOR BIS ISI MARK CERTIFICATION