What are the types of sheet metal materials?

　　A wide variety of sheet-metal materials are suitable for stamping, and those commonly used in the electronics and electrical industries include:

　　1. Common cold-rolled sheet SPCC

　　SPCC refers to steel ingots that are continuously cold-rolled on a rolling mill to produce steel sheet coils or sheets of the required thickness. The surface of SPCC is completely unprotected and readily oxidizes when exposed to air; this oxidation accelerates in humid environments, leading to the formation of dark reddish-brown rust. Therefore, prior to use, the surface must be coated with paint, electroplated, or otherwise protected.

　　2. SECC Galvanized Steel Sheet

　　SECC is manufactured from standard cold-rolled steel coil, which undergoes degreasing, pickling, electro-galvanizing, and a series of post-treatment processes on a continuous electro-galvanizing line to produce an electro-galvanized product. SECC not only exhibits the mechanical properties and comparable formability of conventional cold-rolled steel sheet but also boasts superior corrosion resistance and an aesthetically pleasing finish. As a result, it is highly competitive and often used as a substitute in the electronics, home appliance, and furniture markets. For example, SECC is widely employed in computer cases.

　　3. Hot-Dip Galvanized Steel Sheet SGCC

　　Hot-dip galvanized steel coil is produced by first cleaning and annealing hot-rolled, pickled, or cold-rolled semi-finished steel strips, then immersing them in a molten zinc bath at approximately 460°C to deposit a zinc coating. The coated strip is subsequently subjected to tempering and leveling, followed by chemical treatment. Compared with SECC, SGCC material is harder and exhibits poorer ductility (therefore unsuitable for deep-drawing applications), has a thicker zinc coating, and demonstrates inferior weldability.

　　4. Stainless Steel SUS301

　　Cr (chromium) content is lower than that of SUS304, resulting in poorer corrosion resistance; however, cold working can impart excellent tensile strength and hardness, along with good elasticity, making it well suited for applications such as spring clips and EMI shielding.

　　5. Stainless Steel SUS304

　　One of the most widely used stainless steels, it exhibits superior corrosion and heat resistance compared with chromium-containing steels due to its nickel content, while also boasting excellent mechanical properties. It does not harden through heat treatment and lacks elasticity.