HSN CODE - 7308 : STRUCTURES (EXCLUDING PREFABRICATED BUILDINGS OF HEADING 9406) AND PARTS OF STRUCTURES (FOR EXAMPLE, BRIDGES AND BRIDGE-SECTIONS, LOCK-GATES, TOWERS, LATTICE MASTS, ROOFS, ROOFING FRAMEWORKS, DOORS AND WINDOWS AND THEIR FRAMES AND THRESHOLDS FOR DOORS, SHUTTERS, BALUSTRADES, PILLARS AND COLUMNS), OF IRON OR STEEL; PLATES, RODS, ANGLES, SHAPES, SECTIONS, TUBES AND THE LIKE, PREPARED FOR USE IN STRUCTURES OF IRON OR STEEL

Harmonised System of Nomenclature (HSN Codes) 7308 are used for the STRUCTURES (EXCLUDING PREFABRICATED BUILDINGS OF HEADING 9406) AND PARTS OF STRUCTURES (FOR EXAMPLE, BRIDGES AND BRIDGE-SECTIONS, LOCK-GATES, TOWERS, LATTICE MASTS, ROOFS, ROOFING FRAMEWORKS, DOORS AND WINDOWS AND THEIR FRAMES AND THRESHOLDS FOR DOORS, SHUTTERS, BALUSTRADES, PILLARS AND COLUMNS), OF IRON OR STEEL; PLATES, RODS, ANGLES, SHAPES, SECTIONS, TUBES AND THE LIKE, PREPARED FOR USE IN STRUCTURES OF IRON OR STEEL products under Goods and Service Tax classification.

India was originally using 6 digit HSN codes to classify commodities but later two more digits were added to make the codes more precise, resulting in an 8 digit classification.