What is Sheet Metal and Sheet Metal Process?

What is sheet metal?

With the development of the industry and the demand for modern rapid models, precision sheet metal fabrication services have been increasingly used to produce small batches of parts to facilitate the development and testing of new products.

1. Sheet metal definition

Sheet metal is a comprehensive cold working process for metal sheets (usually below 6mm). And the sheet metal process including shearing, punching, cutting, compounding, folding, riveting, splicing, forming, surface treatment, etc. The products processed by the sheet metal process are called sheet metal parts or sheet metal components

2, Sheet metal equipment

Generally speaking, the sheet metal process’s necessary equipment includes Shear Machine, CNC Punching Machine/Laser, Plasma, Waterjet Cutting Machine, Bending Machine, Drilling Machine, and various Auxiliary equipment such as decoiler, leveling machine, deburring machine, spot welding machine, etc.

3, Sheet metal software

In 3D software, SolidWorks, UG, Pro/E, SolidEdge, TopSolid, CATIA, etc. all of them can be used for custom sheet metal fabrication services, mainly through the editing of 3D graphics to obtain the data required for sheet metal processing (such as unfolded drawings, bending Line, etc.) and provide data for CNC Punching Machine/Laser, Plasma, Waterjet Cutting Machine (Laser, Plasma, Waterjet Cutting Machine)/Combination Machine and CNC Bending Machine, etc.

Sheet metal history

1, Before the 20th century

The development history of sheet metal technology has a long history. Starting from the ancient bronzes and ironware, people used various methods to smelt metal materials.

With the improvement of smelting technology, they gradually smelted sheet metal materials. They learned to use some tools processing these metal plate materials in the embryonic form of sheet metal technology. Before the 20th century, it was mainly handmade sheet metal.

2, From the beginning of the 20th century to the 1980s

Since the beginning of the 20th century, stamping equipment and cold stamping dies have gradually been applied in sheet metal processing. In the 1980s, CNC sheet metal began to appear.

In general, the widespread use of stamping equipment and cold stamping dies, and the popularization of CNC automation equipment are two milestones in the development of sheet metal technology. The former gave birth to stamping, and the latter gave birth to CNC sheet metal.

3, From the 1980s to the present

Since the 1980s, with the rise of the world’s manufacturing industry, stamping and sheet metal industries, one of the primary manufacturing industries, have also achieved unprecedented development.

And with the development of technology, many sheet metal services companies and industries have improved continuously, such as laser technology guidance, which is useful for developing the sheet metal processing industry.

Sheet metal materials

The materials generally used in sheet metal processing are cold rolled plate (SPCC), hot rolled plate (SHCC), galvanized plate (SECC, SGCC), copper (CU) brass, aluminum plate (6061, 5052, 1010, 1060, 6063), Duralumin, etc.), stainless steel (mirror surface, brushed surface, matte surface),

According to the different functions of the product, the choice of materials is other and generally needs to be considered from its use and cost.

1, Ordinary cold-rolled plate SPCC

SPCC refers to the continuous rolling of steel ingots through cold rolling mills into steel coils or required thickness sheets.

There is no protection on the surface of SPCC sheet metal materials, and it is easily oxidized when exposed to the air, especially in a humid environment, the oxidation speed is accelerated, and dark red rust appears. The surface should be painted, electroplated, or other protection when used.

2, The substrate of galvanized steel sheet SECC

SECC is a general cold-rolled steel coil, which becomes an electro-galvanized product after degreasing, pickling, electroplating, and various post-treatment processes on the continuous electro-galvanizing production line.

SECC sheet metal material has the mechanical properties and similar processability of general cold-rolled steel sheets and has superior corrosion resistance and decorative appearance. It is highly competitive and replaceable in the market of electronic products, home appliances, and furniture. For example, SECC is commonly used in computer cases.

3, Hot-dip galvanized steel sheet SGCC

SGCC sheet metal materials refer to the semi-finished product after hot-rolled pickling or cold-rolling, cleaned, annealed, and immersed in a molten zinc tank at a temperature of about 460°C to plate the steel. The zinc layer is then tempered, leveled, and chemically treated.

SGCC material is harder than SECC material, has low ductility (avoid deep drawing design), thicker zinc layer, and poor electric weldability.

4, The content of stainless steel SUS301

Cr (chromium) is lower than that of SUS304, and its corrosion resistance is poor, but it can get reasonable tensile force and hardness after cold working, and it has good elasticity. It is mostly used for shrapnel springs and anti-EMI.

5, Stainless steel SUS304

Stainless steel sheet metal fabrication material is one of the most widely used. Because it contains Ni (nickel), it has better corrosion resistance and heat resistance than Cr (chromium) steel. It has excellent mechanical properties, no heat treatment hardening phenomenon, and no elasticity.

Sheet metal material list

Sheet metal process

Generally, the sheet metal fabrication process include:

• sheet metal drawing
• sheet metal blanking
• sheet metal cutting
• Sheet metal stamping
• sheet metal bending
• Sheet Metal Welding
• Sheet Metal Surface Finishing

Sheet metal drawing:

After the sheet metal drawings are in hand, choose different blanking methods according to the additional unfolded pictures and batches, including laser, CNC punching, shearing, molds, etc. Then, make the corresponding unfolding to the drawings.

The CNC punch press is affected by the tool. For the processing of some special-shaped workpieces and irregular holes, large burrs will appear on the edges.

The later deburring processing must be carried out, and the accuracy of the workpiece will be affected to a certain extent; laser processing has no tools. Restrictions, flat sections, suitable for processing special-shaped workpieces, but it takes a long time to process small workpieces.

Place the worktable next to the CNC and the laser to facilitate the sheet material placement on the machine for processing and reduce lifting the board.

Sheet metal blanking

There are four main methods for sheet metal blanking:

A. Sheet metal shearing: It uses a shearing machine to cut simple material parts. It is mainly used for mold blanking and forming. The cost is low, and the accuracy is less than 0.2, but it can only process strips or blocks without holes and corners material.

B. Sheet metal punching services: It uses the punch machine to punch out the flat parts after unfolding the parts on the plate in one or more steps to form various materials. Its advantages are short working hours, high efficiency, high precision, low cost, and suitable for large quantities—production and design molds.

4. Sheet metal NC blanking. When NC blanking, you must first write an NC machining program. Use the programming software to program the drawn unfolding into a program that can be recognized by the NC machine tool, and let it punch on the plate one step at a time according to these programs.

Cut flat pieces of various shapes, but their structure is affected by the cutter’s structure, the cost is low, and the accuracy is less than 0.15.

D. Laser cutting uses the laser cutting method to cut out the flat plate’s structure and shape on a large flat plate. Like NC cutting, it is necessary to write a laser program. It can load various complex shapes of flat parts with high cost and accuracy, at 0.1.

Sheet metal stamping

The custom sheet metal stampings use molds and stamping equipment to apply pressure to the sheet metal to cause plastic deformation or separation of the sheet metal, thereby obtaining parts with a particular shape, size, and performance (stamping parts)

The custom metal stampings process can be divided into four basic processes:

• Punching: The stamping process (including punching, blanking, trimming, cutting, etc.) separates the sheet.
• Bending: A stamping process in which a sheet is bent into a certain angle and shape along the bending line.
• Deep drawing: A stamping process that transforms a flat sheet into various open hollow parts or further changes its shape and size.
• Local forming: the stamping process (including flanging, bulging, leveling and shaping processes, etc.) that uses various local deformations of different properties to change the shape of the blank or stamping part.

If you want, please check our custom metal stamping services center to get more informaiton.

Sheet metal bending

Sheet metal bending service is also called sheet metal folding services.

The bending of sheet metal refers to the use of sheet metal bending tools to change the angle of the sheet or plate.

There are two methods for sheet metal bending services:

• One method is die bending, which is used for sheet metal structures with complex structures, small volumes, and large-scale processing;
• The other is bending sheet metal by machine, which is used for structural processing dimensions. The sheet metal structure is relatively large, or the output is not too large.

Commonly used bending dies.

Commonly used bending molds, as shown below. To extend the mold’s life, round corners should be used as much as possible when designing parts.

Use the bending knife of the bending machine to bend and shape the sheet metal parts.

Below is the bending tool:

At Jita, You can get many types of custom sheet metal bending services.

Sheet Metal Welding

There are three commonly used welding methods for sheet metal: argon arc welding, carbon dioxide gas shielded welding, and laser welding.

• Argon-protected welding: The use of argon gas to protect the metal welding material, through the high current to melt the welding material into a liquid form on the welded base material to form a molten pool, so that the welded metal and welding material can achieve a metallurgical combination. Kind of welding technology.
• Carbon dioxide arc welding: a method of welding with carbon dioxide as a shielding gas.
• Laser welding: A method of welding with the heat generated by bombarding the weldment with a focused laser beam as the energy source.

Sheet Metal Finishing

The surface treatment of sheet metal parts is also an essential part of the sheet metal processing process because it prevents parts from rusting and beautifying products’ appearance.

The surface pretreatment of sheet metal parts is mainly to remove oil, oxide scale, rust, etc. It prepares for the surface post-treatment, and the post-treatment is mostly sprayed (baking) paint, plastic spray, anti-rust coating, etc.

Several standard surface treatment methods for sheet metal processing are wire drawing, sandblasting, paint spraying, powder spraying, electroplating, anodizing, and silk screen printing. To

A. Drawing

The so-called sheet metal drawing is to place the material between the upper and lower wheels of the wire drawing machine. The sand belt is attached to the wheel. Different, the thickness of the traces is also different. The primary function is to beautify the appearance.

Besides, wire drawing is also called rubbing! Commonly used materials for this surface treatment process: generally, aluminum and stainless steel plates are considered surface treatment methods of wire drawing.

B. Sandblasting

The sand particles are hit on the workpiece’s surface by the sandblasting machine’s wind, forming a dense layer of pits on the workpiece’s surface.

The primary function is to remove the dirt and rust on the workpiece’s surface, increase the adhesion of the surface of the workpiece, and do it for the subsequent surface treatment. Ready. Commonly used materials for this surface treatment process: cold-rolled sheet, hot-rolled sheet, aluminum, etc.

C. Powder coated

The powder is polarized and uniformly attached to the product’s surface with the opposite polarity under the electric field force’s action. Powder spraying can be divided into gloss, matt, and semi-glossy.

High-gloss powder spraying effect:

Matte powder spraying effect:

Semi-gloss dusting:

D. Painting

Spraying is a coating method in which spray guns or disc atomizers are dispersed into uniform and fine droplets using pressure or the centrifugal force and applied to the object’s surface to be coated.

The color effect of spray paint will be better. The paint film’s thickness is relatively thin, suitable for some precision products, and the cost is higher—common materials for this surface treatment process: cold-rolled sheet, hot-rolled sheet, etc.

E. Electroplating

A layer of other metals is attached to the material’s surface to increase the metal’s corrosion resistance and achieve a specific beautification effect through a chemical reaction. It is a commonly used surface treatment method.
Types of electroplating:

a. Galvanized:

b. Chrome plating

c. Gilded

d. Copper plating

e. Nickel plating

F. Anodized.

The metal on the workpiece’s surface is oxidized to form a thick protective film on workpiece’s surface to increase the workpiece’s corrosion resistance. Generally, there are two ways of chemical oxidation and anodic oxidation. It is a commonly used surface treatment method, usually with primary color anodizing and black anodizing—common materials for this surface treatment process: aluminum.

G. Silkscreen

The process of screen printing various logos on the material’s surface generally has two methods: flat-screen printing and pad printing. The main principle is the same as the principle of camera film imaging, and it is also an exposure process. Flat-screen printing is mainly used on available planes, but pad printing is needed to encounter deep pits. Usually used in trademarks, use signs, warning signs, etc.

Sheet metal advantages

Precision sheet metal fabrication has the characteristics of lightweight, high strength, electrical conductivity (can be used for electromagnetic shielding), low cost, and good mass production performance.

Custom Sheet metal fabrication service has been widely used in electronic appliances, communications, the automotive industry, medical equipment, and other fields, such as computer cases, mobile phones, and MP3; sheet metal is an indispensable part.

As sheet metal applications become more and more extensive, the design of sheet metal components has become an essential part of the product development process.

Mechanical engineers must be proficient in custom sheet metal parts’ design skills so that the designed sheet metal meets the product requirements. The function and appearance requirements can make the stamping die manufacturing simple and low cost.

Advantages of custom sheet metal work:

1. The material utilization rate is high, and the material cost of the workpiece is low
2. The processing technology is simple, can reduce the production cost and save the production cost

Sheet metal cost

Sheet metal cost estimator

The price of the Sheet metal parts = material cost + processing cost + surface finish cost + packaging cost. If molds are needed for sheet metal, mold costs must be added.
For the prototype part, the minimum price is $5For mass-produced products, the minimum price is $0.001.

What is the sheet metal used for

Sheet metal fabrication part has the advantages of a lightweight, high strength, electrical conductivity (can be used for electromagnetic shielding), low cost, and good mass production performance. It has been widely used in electrical appliances, communications, the automotive industry, medical equipment, and other fields.

Sheet metal applications

sheet metal applications in industry

Sheet metal parts have been widely used in various industries such as machinery manufacturing, electronics, and electrical appliances. As large as car covering parts, as small as clocks, instruments, and instrument components, most of them use sheet metal parts.

Sheet metal used in communication equipment

Wireless Communication Gateway Enclosure

Rackmount chassis

Sheet metal used in automotive

motor mount:

Automotive support bracket:

Car door body:

Sheet metal used in electronic

Stainless steel series:

EMI Shielding Case

Switch box:

Sheet metal used in consumer

Loudspeaker mesh:

A/C case:

Sheet metal used in construction

Stainless door:

Sheet metal in automation

Automation equipment

Sheet metal in healthcare

Medical equipment case:

Sheet metal in food
Stainless food case:

Sheet metal in furniture
Stainless furniture:

Sheet metal in display