What is Metal Sheet ?
Sheet metal is metal that has been formed into thin, flat pieces, usually through an industrial process. It is generally produced in sheets less than 6 mm thick. Sheet metal is one of the fundamental shapes used in metallurgy and can be cut and bent into many different shapes.
Sheet metal is available in a variety of materials, standard sizes and thicknesses, typically ranging from 0.5 to 6 millimeters. It is commonly used in a wide range of applications, from automobile bodies and airplane wings to building roofs and HVAC ducts.
Creating objects from sheet metal involves specialized tools and techniques such as hammers, cutouts, digital imaging, and laser welding. Sheet metal work requires skill and skill to shape the metal into desired shapes.
properties
Sheet metal is known for ductility , allowing it to be molded into various shapes without breaking or cracking. This malleability is essential when manufacturing, as it allows the material to be folded, stretched and printed during the production process.
The thickness of the sheet metal is also an important factor and can vary from extremely thin to several centimeters. Thickness is usually specified using a gauge number, where a lower gauge represents thicker material. The use of different thicknesses makes the sheet metal suitable for a variety of applications, from lightweight electronics enclosures to heavy machinery parts.
Another important property of sheet metal is its strength-to-weight ratio . This means that it maintains its strength even when the thickness is reduced, allowing for lightweight but robust designs.
Materials
There are several materials that can be used to produce sheet metal:
- Aluminum : Lightweight and corrosion-resistant, aluminum is commonly applied in the aerospace and automotive industries.
- Steel : Carbon steel is a popular choice because of its balance of strength and ductility. Stainless steel has greater resistance to corrosion, making it ideal for environments prone to rust.
- Copper : With its excellent thermal and electrical conductivity, copper is often used in electrical components and heat exchangers.
- Brass and Bronze : These copper alloys have an attractive aesthetic appearance and maintain excellent corrosion resistance, making them perfect for decorative components.
Different materials have unique properties that make them suitable for specific applications, allowing sheet metal to be a versatile and widely used material in many industries.
Types of Sheet Metal
Commonly used sheet metal materials can be divided into two categories, which are:
- Galvanized steel
- Stainless steel
Galvanized steel
Galvanized steel can be mainly divided into:
- Electrogalvanized sheet
- Hot dip metal coated sheet
Let's compare the above two galvanized steel sheets through a table.
| Electrogalvanized sheet (EG/SECC) | Hot dip metal coated sheet (GI) | |
| Base metal | Cold rolled annealed steel | Cold rolled hard steel sheet |
| Pretreatment | Electroplating | Hot sauce |
| Zinc plating | Hard coating for thickness | Hard to thin coating |
| plating surface | The zinc layer is adsorbed on the surface of the steel, and the surface is smooth and free from zinc spangles. | Solidified structure of zinc layer, which may or may not contain zinc sequins. |
| Plating organization | Pure zinc coating | The outermost layer is pure zinc and the inner layer is iron-zinc alloy. |
| Mechanical performance | Same as base metal | After annealing, it shows aging hardening; the material is soft. |
| Maximum material thickness | The common thickness of the material can be seen | 0.6-1.5mm |
| Corrosion resistance | Thin, poor coating | The coating is thick and good. Can be added with anti-fingerprint coating |
| Price | Dear | Cheap |
Stainless steel
It is a general term for acid-resistant stainless steel, which resists atmospheric corrosion, acid, alkali, salt and other media.
To achieve stainless corrosion resistance, the amount of chromium (Cr) should not be less than 13%. Additionally, nickel (Ni) or molybdenum (Mo) can be added to enhance the effect.
Due to the various types and alloy content, there are many types of acid-resistant stainless steel.
See too:
- Definitive Guide to Stainless Steel Grades
Stainless Steel Features:
- Good corrosion resistance
- Good shine
- High strength
- Has a certain degree of elasticity
- Dear
Stainless steel material properties:
Ferritic stainless steel:
- High chromium (Cr) content
- Good properties and resistance to high temperature oxidation
Austenitic Stainless Steel:
- Typical grades: Cr18Ni9 and Cr18Ni9T1
- Non-magnetic
- Good corrosion resistance
- Good temperature resistance and high temperature oxidation resistance
- Good plasticity
- Good impact resistance
- No gap effect
- Excellent weldability
- Widely used
- Generally has low strength and low yield point
- It cannot be strengthened by heat treatment, but after cold pressing the tensile strength is high and the elasticity improves
- The strength obtained through cold drawing at high temperatures is easily weakened and should not be used for high load applications
Martensitic Stainless Steel:
- Typical grades: 2Cr13 and GX-8
- Magnetic property
- Excellent shock absorption and good thermal conductivity
- High strength and yield limit
- Good comprehensive mechanical properties after heat treatment and strengthening
- High carbon content requires tempering after welding to eliminate stress
- Mainly used for load-bearing parts.
See too:
- Why Stainless Steel Rusts and How to Prevent It From Rusting
- Type of metal
Features of sheet metal
Sheet metal is characterized by its light weight, high strength, conductivity (which makes it suitable for electromagnetic shielding), low cost and good production efficiency.
It has found wide use in various industries such as electronics, communications, automobiles, and medical devices. For example, it is a crucial component in computer cases, cell phones, and MP3 players.
As the application of sheet metal continues to expand, the design of sheet metal parts has become a critical aspect of product development. Mechanical engineers must be well versed in the design of sheet metal components to ensure parts meet necessary functional and aesthetic requirements while keeping stamping die production simple and cost-effective.
Main Applications of Sheet Metal
There are many sheet metal materials suitable for stamping processing, which are widely used in the electronics and electrical industry. These include:
Common Cold Rolled Sheet (SPCC) – SPCC is a steel material produced by continuously rolling steel ingots into steel coils or sheets of desired thickness using a cold rolling mill. However, the SPCC surface is not protected and can easily oxidize when exposed to air, particularly in humid environments where rust appears more quickly. To prevent this, the surface must be painted, coated or otherwise protected during use.
SECC Galvanized Steel Plate – SECC is a type of galvanized steel produced from general cold-rolled steel coils. After undergoing degreasing, pickling, electroplating and other post-treatment processes, it becomes an electrogalvanized product that offers excellent corrosion resistance and decorative appearance. It is widely used in the electronics, household appliances and furniture industries, for example in computer chassis.
Hot Dip Galvanized Steel Plate (SGCC) – SGCC is a material produced by hot or cold rolling, washing and annealing the semi-finished product. The material is then immersed in a bath of molten zinc at a temperature of about 460°C to produce a zinc-coated material. SGCC is harder than SECC, but has low ductility, a thicker zinc layer and poor weldability.
SUS301 stainless steel – This type of steel has lower chromium content compared to SUS304 and has low corrosion resistance. However, it can be cold processed to obtain good tensile strength and hardness and has good elasticity, making it ideal for use in elastic springs and anti-EMI applications.
SUS304 Stainless Steel – SUS304 is one of the most widely used stainless steels and contains nickel, which provides better corrosion and heat resistance than chromium-containing steels. It has very good mechanical properties and does not harden during heat treatment and does not have elasticity.
Sheet Metal Process
Generally speaking, the basic equipment for sheet metal processing includes a cutting machine, a CNC punching machine, a laser cutting machine, a plasma cutting machine, a waterjet cutting machine, a bending machine, a drilling machine and various auxiliary equipment, such as unwinder, leveling machine, deburring machine and spot welding machine.
Typically, the four most important steps in sheet metal processing are shearing, punching/cutting/bending/rolling, welding and surface treatment.
Sheet metal is also sometimes called “plate metal”. The process of molding metal plates into the desired shape and size is carried out through plastic deformation by manual or die stamping. More complex parts can be formed through welding or a small amount of mechanical processing. Examples of sheet metal parts include chimneys, sheet metal furnaces, and automobile bodies.
Sheet metal processing involves using metal plates to create parts such as chimneys, iron drums, oil tanks, ventilation pipes, elbows, round places, funnel shapes, and more. This process requires certain geometric knowledge and involves cutting, bending and buckling, bending and forming, welding and riveting.
Sheet metal parts are thin pieces of hardware that can be processed by stamping, bending, stretching and other means. They have a constant thickness throughout processing and are different from cast, forged or machined parts. Examples of sheet metal parts include the iron shell of an automobile and some stainless steel kitchen appliances.
Modern sheet metal technology includes filament winding, laser cutting, heavy processing, metal gluing, metal drawing, plasma cutting, precision welding, forming, sheet metal bending, forging, waterjet cutting and welding precision.
Surface treatment is an important part of the sheet metal processing process because it prevents rust and improves the appearance of the product. Surface pre-treatment removes oil stains, oxide scale and rust, prepares the surface for post-treatment, and post-treatment mainly includes spray painting (baking), plastic spraying and coating with an anti-rust layer.
3D software such as Solidworks, UG, Pro/E, SolidEdge, Topsolid and CATIA feature sheet metal parts and are mainly used to obtain data required for sheet metal processing through editing 3D graphics. This data provides information for CNC punch/laser, plasma, waterjet cutting machine/combination machine and CNC press brake.
Manufacturing processes
Cut
In the sheet metal manufacturing process, the first step to be performed is cutting. Various techniques are used to cut sheet metal, such as shearing, laser cutting, plasma cutting, and waterjet cutting. Shearing is a simple mechanical process that uses a blade to trim edges or make straight cuts. In contrast, laser cutting employs a focused laser beam that melts easily through metal, resulting in precise cuts and minimal material waste.
Doubling
After cutting, bend the sheet to create the desired shape. Some common bending methods include air bending, nesting, and coining. Air bending, the most popular technique, involves applying force to metal through a punch and die, and offers high precision and flexibility. Laying and coining, on the other hand, require more force but ensure that the metal bends precisely at predefined angles.
Stamping
Stamping is another crucial step in the manufacturing process, where a die and press are used to create raised or cut-out sections in sheet metal. Techniques such as embossing, coining, and flanging are common in stamping. These methods add intricate details and patterns to the metal surface. Stamping can also be combined with cutting, offering versatility and expanding the range of final products I can create.
Forming
Lastly, perform forming to further shape the sheet metal. Forming processes include roll forming, stretch forming and deep drawing. Roll forming involves passing the metal through a series of rollers to create a continuous profile while maintaining the integrity of the material. During stretch forming, attach the sheet metal to a tensioned machine and apply pressure to obtain the desired shape without causing defects. Deep drawing, on the other hand, pulls the metal into the die cavity, creating deep, hollow shapes with uniform walls.
Overall, these manufacturing processes allow me to efficiently create a wide range of sheet metal products that serve a variety of industries and applications.
Advantages and disadvantages
Pros
In my experience, working with sheet metal offers several advantages. First, it provides a remarkable weight-to-strength ratio, making it ideal for various industries such as aerospace, automotive, and construction. Additionally, sheet metal is highly customizable, allowing for easy manipulation and modification to meet specific project requirements. This flexibility contributes to minimal waste generation during the manufacturing process, making it an environmentally friendly choice.
Another advantage I discovered is that sheet metal offers excellent conductive properties, making it efficient for electrical and thermal applications. It is also highly resistant to corrosion, ensuring long-term durability and reliability.
Cons
Despite its advantages, there are some disadvantages to using sheet metal. A major concern I have encountered is their susceptibility to warping and distortion during the manufacturing process. High temperatures and mechanical stresses can potentially compromise its structural integrity, leading to costly repairs or product failure.
Another problem I faced is the risk of injury during handling and manufacturing due to sharp edges and burrs. Proper safety protocols must be implemented to minimize the chances of accidents while working with sheet metal.
Lastly, although sheet metal provides versatility in manufacturing, it may not be suitable for all applications. Its thin walls can limit its strength and rigidity, making it unsuitable for heavy or high-pressure projects.
