What is a sheet metal part?

Sheet Metal Parts: Sheet metal is a comprehensive cold-working process applied to thin metal sheets—typically less than 6 mm thick—and encompasses operations such as shearing, punching/cutting/combined punching and cutting, bending, welding, riveting, splicing, and forming (e.g., for automobile bodies). A defining characteristic is the uniform thickness of each part. Products manufactured through sheet-metal processes are referred to as sheet-metal parts. The specific meaning of “sheet-metal part” can vary across industries, often serving as a term used during assembly or component integration. Sheet-Metal Materials: A wide variety of sheet-metal materials are suitable for stamping and other forming processes. In the electronics and electrical appliance industry, common sheet-metal materials include: 1. Ordinary Cold-Rolled Steel Sheet SPCC SPCC refers to steel ingots that are continuously rolled by a cold-rolling mill into steel coils or sheets of the desired thickness. SPCC has no surface protection, making it highly susceptible to oxidation when exposed to air—especially in humid environments, where oxidation accelerates, leading to the formation of dark-red iron rust. Therefore, SPCC surfaces typically require painting, electroplating, or other protective coatings before use. 2. Electro-Galvanized Steel Sheet SECC SECC is made from standard cold-rolled steel coils, which undergo degreasing, pickling, electro-galvanizing, and various post-treatment processes on an automated continuous galvanizing line to produce electro-galvanized products. SECC not only retains the mechanical properties and similar formability of ordinary cold-rolled steel sheets but also offers superior corrosion resistance and an aesthetically pleasing finish. As a result, it is highly competitive and increasingly replacing traditional materials in the electronics, home-appliance, and furniture markets. For example, SECC is widely used in computer cases. 3. Hot-Dip Galvanized Steel Sheet SGCC Hot-dip galvanized steel coils are produced by first cleaning and annealing semi-finished hot-rolled or cold-rolled steel, then immersing the material in a molten zinc bath at approximately 460°C to coat the steel surface with a layer of zinc. The material is subsequently tempered, leveled, and subjected to chemical treatments. Compared with SECC, SGCC is harder, less ductile (making it unsuitable for deep-drawing applications), has a thicker zinc coating, and exhibits poorer weldability. 4. Stainless Steel SUS301 SUS301 contains a lower chromium content than SUS304, resulting in slightly poorer corrosion resistance. However, after cold working, it achieves excellent tensile strength and hardness, along with good elasticity, making it ideal for applications such as spring clips and EMI shielding. 5. Stainless Steel SUS304 One of the most widely used stainless steels, SUS304 owes its superior corrosion and heat resistance to its nickel content. It also boasts outstanding mechanical properties, does not harden through heat treatment, and lacks significant elasticity.

Sheet metal parts: Sheet metal is a comprehensive cold-working process applied to thin metal sheets (typically less than 6 mm thick), encompassing operations such as shearing, punching/cutting/combined cutting, bending, welding, riveting, splicing, and forming (e.g., for automotive body panels). A defining characteristic of sheet metal is the uniform thickness of individual parts. Products manufactured using sheet-metal processes are referred to as sheet-metal parts. The specific meaning of “sheet-metal part” can vary across industries and is often used as a term of reference during assembly or component integration.

Sheet metal materials: A wide variety of sheet metal materials are suitable for stamping, and those commonly used in the electronics and electrical appliance industry 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, after undergoing degreasing, pickling, electro-galvanizing, and a series of post-treatment processes on a continuous electro-galvanizing line, becomes 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 increasingly substitutive in markets for electronic products, home appliances, and furniture. For instance, SECC is widely used 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 sheets, then immersing them in a molten zinc bath at approximately 460°C to deposit a zinc coating. The coated strips are subsequently stress-relieved, leveled, and subjected to 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 suitable 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.