Flat-rolled steel production begins at the hot strip mill, where slabs of steel are heated and rolled through a series of stands to produce hot-rolled coils. The hot rolling process takes place above the steel’s recrystallization temperature, allowing significant reduction in thickness with relatively low rolling forces. Hot-rolled coils have a characteristic blue-grey scale surface and are used directly in structural and general engineering applications. For applications requiring tighter dimensional tolerances, smoother surfaces, or enhanced mechanical properties, hot-rolled coils are further processed by cold rolling at ambient temperature. The cold rolling process hardens the steel through work hardening, producing cold-rolled coils with a bright, smooth surface. Subsequent annealing or temper rolling restores ductility and achieves the required mechanical property balance