The common materials for sheet metal addition include cold rolled steel plate (SPCC), hot rolled plate (SHCC), galvanized steel plate (SECC, SGCC), copper (Cu) brass, copper, aluminum and aluminum profiles。

1.Cold rolled steel plate, mainly used for electroplating and drying coating, has the advantages of low cost, easy forming and material thickness ≤ 3.2mm。

二、Hot rolled steel sheet, material t ≥ 3.0 mm, also used for electroplating and coating parts, low cost, but not easy to form, mainly flat parts。

3.Galvanized sheet SECC, SGCC. SECC electrolytic plate is divided into N kinds of materials, P materials, N kinds of materials are mainly without surface treatment, high cost, P material is used for spraying parts。

Copper; mainly used in conductive materials, surface treatment for chromium, chromium, or untreated, high cost。

5.Aluminum plate; generally used surface chromate (j11 ≤ a), oxidation (conductive oxidation, chemical oxidation), high cost silver plating, nickel plating。

In the process of sheet metal processing, after blanking, input the next process, and different workpieces enter the corresponding processing process according to the processing requirements. There are bending, pressing, riveting, flanging and tapping, spot welding, protruding packaging, cross-section difference, etc. sometimes the nut or nut is pressed after bending once or twice. The processing of the convex bag and section difference center should be considered first, so as not to process other processes first and then intervene, and the required processing cannot be completed. When there are hooks on the upper cover or lower shell, if the welding cannot be contacted after bending, it should be treated before bending。

The bending tool and groove should be determined according to the drawing size and the thickness of the data. The key to choose the upper die is to prevent the deformation caused by the collision between the product and the tool (in the same product, different models of the upper die can be used), and the selection of the lower die should be determined according to the thickness of the plate. The second is to determine the bending sequence. The general bending law is first internal, then external, first small, then large, first special, and then ordinary. For the workpiece with blank holder, bend the workpiece to 30 ° to 40 ° first, and then press the workpiece to death with flat die。