Sheet metal fabrication, provided by sheet metal part manufacturers, is a comprehensive cold working process for thin metal sheets (usually less than 6mm), including shearing, punching, cutting, laminating, folding, welding, riveting, splicing, forming (e.g. auto body), etc. The distinguishing feature is the consistent thickness of the same part. 

1. Materials used in sheet metal fabrication

The materials used in sheet metal fabrication are generally cold-rolled sheet (SPCC), hot-rolled sheet (SHCC), galvanized sheet (SECC, SGCC), copper (CU), brass, red copper, beryllium copper, aluminum (6061, 5052, 1010, 1060, 6063, hard aluminum, etc.), stainless steel (mirror, brushed surface, matte surface). The choice of materials depends on the functions of the product and costs. Detailed introduction of the materials is as follows:

(1) Cold-rolled plate SPCC

The material thickness is ≤ 3.2mm. They are mainly manufactured into electroplating and baking painted parts with the features of low cost and easy to shape. 

(2) Hot rolled sheet SHCC

Its material thickness is ≥ 3.0mm. Same as SPCC, they also are mainly manufactured into electroplating and baking painted parts. They are low-cost, but difficult to form and primarily used for flat parts.

(3) Galvanized sheet SECC & SGCC

SECC electrolytic sheet is divided into N material and P material. The parts made by N material won’t do surface treatment, and the cost is relatively high. The P material is for painted parts.

(4) Copper

It is mainly used for conductive parts, usually with its nickel-plating surface treatment, chromium-plated, or no finishing. The cost of copper is also relatively high.

(5) Aluminum plate

They are generally with chromate (J11-A), and oxidation (conductive oxidation and chemical oxidation), which is costly. They can also be silver-plated and nickel-plated.

(6) Aluminum profile

Aluminum profiles have complex cross-sectional structures. They are widely used for plug-in boxes. The surface treatment is the same as for aluminum plates.

(7) Stainless steel

They are mainly manufactured without any surface treatment. The price is relatively high.

2. Processing steps of sheet metal fabrication

There are a variety of processes used to fabricate sheet metal parts today, including filament winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, metal sheet bending and forming, die forging, and water jet cutting. Usually, the three most important steps in sheet metal manufacturers are shearing, punching or cutting, and folding.

To be specific, the whole sheet metal fabrication process is as follows: 

Sheet metal parts design → technical drawing → making unfolding diagram (CNC programming) → undercutting (punching) → bending → riveting → welding → surface treatment (as per requirement) → assembly → packaging and shipment.

The equipment of sheet metal part manufacturers involved includes shear machines, CNC punching machines, laser/plasma/waterjet cutting machines or combination machines, bending machines, and various auxiliary equipment such as uncoilers, leveling machines, deburring machines, spot welders, etc.

Sheet metal manufacturers usually decide the specific processes and machines based on the actual designs of the product.

3. Commonly used surface treatments of sheet metal fabrication

(1) Electroplating

Via electroplating, the charged ions are attached to the part’s surface under the action of the electric field to form a plating layer. It is a chemical change, including galvanizing, chromium plating, gold plating, copper plating, nickel plating, etc. All the metals can be electroplated if you want.

(2) Powder painting

The powder is polarized and evenly attached to the product's surface with opposite polarity under the action of the electric field force. It is a physical change.

(3) Electrophoresis

Under the action of cathodes and anodes, the electrophoretic paints with charged paint ions move to the surface of the part and deposit to form a coating. It is a chemical change.

4. Applications of sheet metal fabrication

Sheet metal parts are widely applied in electronic appliances, communication, automotive, and medical devices industries because of their lightweight, high strength, electrical conductivity (able to be used for electromagnetic shielding), and low costs. For instance, sheet metal parts are essential components of computer cases, cell phones, and MP3s. 

As one of the sheet metal part manufacturers, X Rapid Technologies provides one-stop sheet metal manufacturing services for prototypes and low-volume production. Feel free to get in touch with us and discuss your requirements. You will get free quotes within 24 hours and kick-start your projects soon.