Galvanized Sheet VS Hot Rolled Sheet

GI (Galvanized Iron) sheets and HR (Hot Rolled) sheets are two different types of metal sheets with distinct properties and applications:

Material Composition:

GI Sheets: GI sheets are made from cold-rolled steel coils or mild steel that is coated with a layer of zinc through a process called galvanization. This zinc coating provides corrosion resistance, making GI sheets suitable for outdoor applications.

HR Sheets: HR sheets are made from hot-rolled steel coils. These sheets have not undergone any coating process like galvanization and are primarily made of iron.

Surface Finish:

GI Sheets: GI sheets have a shiny, metallic appearance due to the zinc coating. They have a smooth surface.

HR Sheets: HR sheets have a rough, scaly surface due to the hot rolling process. They may have mill scale or oxide layers on their surface.

Strength and Durability:

GI Sheets: Due to the zinc coating, GI sheets offer better corrosion resistance and durability compared to HR sheets. They are suitable for outdoor applications where exposure to moisture or corrosive elements is a concern.

HR Sheets: HR sheets are strong and durable but are more susceptible to corrosion and rusting compared to GI sheets. They are commonly used in indoor applications or where corrosion resistance is not a critical requirement.

Applications:

GI Sheets: GI sheets are commonly used in roofing, fencing, gutters, and other outdoor structures where corrosion resistance is essential.

HR Sheets: HR sheets are used in various applications such as automotive body panels, structural components, pipes, and industrial machinery where a smooth surface finish is not necessary, or where subsequent coating or treatment can be applied to enhance corrosion resistance.

In summary, while both GI sheets and HR sheets are made from steel, their properties, surface finishes, and applications differ significantly due to the presence or absence of zinc coating and the manufacturing processes involved.