Maximizing customer value is our highest priority!
Call: +86 510 83853889 Email:
Sheet metal processing material selection method and conventional process flow
- 2020-08-02 12:13:26 -

With the rapid development of the manufacturing industry, the sheet metal processing industry has also developed and grown. Now sheet metal involves various fields, such as environmental protection, medicine, engineering, IT, etc., but for any sheet metal product, it has a certain Process flow, sheet metal processing process flow and material substitution are determined by the quality and arrangement of sheet metal products, so how to select materials for products has become a top priority.

Material selection

Sheet metal processing generally uses cold-rolled plates, hot-rolled plates, galvanized plates, aluminum plates, aluminum profiles, stainless steel plates, etc. Depending on the role of the product, the selection of materials is different, and generally needs to be considered from the product, its use and cost. , You can refer to the following instructions:

Cold rolled plate: mainly used for electroplating and baking varnish parts, low cost, easy to form, material thickness 0.2-4mm;

Cold rolled plate pictures

Hot-rolled plate: material T≥3.0mm, also used for electroplating and baking paint parts, low cost, but difficult to form, mainly flat parts;

Hot-rolled plate pictures

Galvanized sheet: mainly used in automobile manufacturing, refrigerated containers, construction, ventilation and heating facilities, furniture manufacturing and other fields;

Galvanized sheet picture

Aluminum plate: generally used surface chromate, oxidation, silver plating, nickel plating, high cost, suitable for home appliances and electronic product enclosures;

Aluminum plate picture

Aluminum profile: materials with complex cross-section structure, widely used in various plug-in boxes, and the surface treatment is the same as that of aluminum plate;

 Aluminum profile picture

Stainless steel: mainly used for any surface treatment, high cost. Mainly used in daily life, food industry, pharmaceuticals, etc.

Stainless steel picture

01 Cutting

There are mainly the following ways of cutting materials:

Shearing machine: Use a shearing machine to cut out the shape of the unfolded drawing. If the length and width dimensions are punched and cut corners, then the punching machine is combined with the die to punch and cut corners to form;

Punch: It uses a punch to punch the unfolded flat parts on the plate in one or more steps into various shapes. Its advantages are short man-hours, high efficiency, high precision, low cost, and it is suitable for mass production;

NC blanking: When NC blanking, you must first write a NC machining program. Use the programming software to program the drawn expanded diagram into a program that can be recognized by the NC data processing machine tool, and then punch it out on the plate step by step according to these programs. Flat pieces of various structural shapes;

Laser cutting: Use laser cutting to cut out the structure and shape of the flat plate on a large flat plate. It needs to write a program like NC blanking. It can cut various complex shapes of flat parts with high cost and accuracy greater than 0.1mm;

Sawing machine: mainly use aluminum profiles, square tubes, round tubes, round bars, etc., with low cost and low precision;

Plasma cutting: mainly for non-ferrous metals (stainless steel, aluminum, copper, titanium, nickel) cutting effect is better.

02 Flanging

It is also called hole extraction, which is to draw a slightly larger hole on a smaller base hole, and then tap it. It is mainly used for thin plate thickness and normal shallow flanging around the hole. The thickness will basically not change. Then you can tap directly.

03 punch

It is a processing procedure that uses mold forming. Generally, punch processing includes punching, corner cutting, blanking, punching, punching and tearing, punching, forming and other processing methods. The processing requires corresponding molds to complete the operation, such as punching Hole blanking die, convex mold, tearing die, hole punching die, forming die, etc.

04 Pressure riveting

Pressure riveting mainly includes pressure riveting nuts, screws, and so on. The operation is completed by hydraulic pressure riveting machine or punching machine, riveting them to the sheet metal parts, and the expansion riveting method. Pay attention to the directionality.

05 Bend

It is a part that folds a flat piece into the required curvature or curvature. The processing needs to be completed with a folding bed and corresponding bending molds, and it also has a certain bending sequence. The principle is that the first bending does not interfere with the next cut, and the interference second bending will occur.

06 welding

Welding, also known as fusion, is a manufacturing process and technology for joining metals or other thermoplastic materials by heating, high temperature or high pressure.


Fusion welding: argon arc welding, submerged arc welding, electroslag welding, gas welding;

Pressure welding: heating and pressing, cold pressing;

Brazing: electric chromium welding, copper wire.

Welding method:

CO₂ gas shielded welding;

Argon arc welding;

Spot welding, etc.;

Robot welding.

07 Surface treatment

Surface treatments generally include phosphating film, electroplating colorful zinc, chromate, baking varnish, oxidation, etc. Phosphating film is generally used for cold-rolled plates and electrolytic plates; electroplated multicolored zinc is generally used for surface treatment of cold-rolled plates; chromate and oxidation are generally used for surface treatment of aluminum plates and aluminum profiles; the specific surface treatment methods are based on customers Depending on the requirements.

08 assembly

Assembling is to assemble multiple accessories or electronic components together according to the assembly process to make it a complete product. During the assembly process, pay attention to the protection of the materials and ensure that the product is intact and undamaged.

Quality control elements of sheet metal processing products

To understand the needs of customers, to have a full understanding of the customer's products when there is a new product or new order, and to understand the customer's requirements for the appearance and size of the product, and the purpose of the product, it needs to be signed and confirmed by both parties;

According to the customer's requirements for the product, plan different product processes, and explain the precautions on the process drawings;

The process department gets the drawings to make process drawings (expanded drawings). The drawings drawn by the technicians must be inspected by another technician and passed the process project review. After the review, the person in charge will sign and confirm and send it to the workshop;

The first piece of CNC blanking must undergo a full inspection, including size, appearance, etc., in mass production, all the first pieces must be inspected before they can be mass produced;

When bending, it is necessary to confirm the bending direction and bending size of the first piece, and start mass production after the confirmation is completed, and re-inspection is required to change the operator or change the mold;

When riveting, consider the height of the stud to select different molds, and then adjust the pressure of the press to ensure that the surface of the stud and the workpiece are flush, and then perform batch bending after confirmation to avoid scrapping of the workpiece;

For welded or bent finished products, carry out sampling inspections on the dimensions according to the requirements of the drawings. During the sampling inspection, each dimension should be confirmed, and the appearance should be fully inspected. The unqualified accessories should be adjusted in time, and the inspection report should be filled in at the same time;

The appearance of surface-treated products must be inspected to ensure that there are no scratches on the surface. Surface treatment is an important guarantee for prolonging the service life of the product;

Products that fail the inspection must not be shipped and should be overhauled. Serious problems need to be reprocessed.