How to distinguish between galvanized sheet and cold-rolled sheet

1. Surface Observation

A galvanized sheet has a silver-white zinc layer on its surface, while a cold-rolled sheet has a gray surface. If no zinc layer is observed, it is likely a cold-rolled sheet.

2. Using a Magnet

Because there is a layer of zinc on the galvanized sheet, a magnet cannot attract it. Cold-rolled sheets are iron-based materials and can be attracted by magnets.

3. Measuring Thickness

Due to the zinc layer, galvanized sheets are thicker than cold-rolled sheets. You can use calipers or a thickness gauge to measure the thickness of the sheet to determine if it has been galvanized.

Summary: Distinguishing between galvanized and cold-rolled sheets requires observing the surface, using a magnet, and measuring the thickness. When choosing sheet metal, different materials should be selected according to specific uses and requirements to ensure project quality and safety.