Sheet metal refers to a thin, flat piece of metal that can be formed and manipulated into various shapes and sizes. Sheet metal can be made from a variety of metals, including steel, aluminum, copper, brass, and nickel.

Sheet metal can be produced in a range of thicknesses, typically ranging from 0.006 inches to 0.25 inches, depending on the material and application. It can be produced in coils or sheets and can be cut, stamped, bent, or welded to create a variety of parts and products.

Sheet metal is commonly used in the manufacturing of a wide range of products, including:

1. Automotive parts: Sheet metal is used to make a variety of automotive parts, including body panels, bumpers, doors, and roofs.

2. Aerospace parts: Sheet metal is used to make components for aerospace structures, including wings, fuselages, and landing gear.

3. HVAC systems: Sheet metal is used in the fabrication of ductwork, air conditioning units, and furnace components.

4. Building construction: Sheet metal is used in the construction of roofs, gutters, and façades.

Sheet metal fabrication involves working with the metal to cut, form, and assemble it into the desired shape. Common sheet metal fabrication processes include cutting, punching, bending, and welding. These processes can be performed manually or using automated equipment, depending on the complexity of the part and the required production volume.

Sheet metal can be made from a range of different metals and alloys, each with their own unique properties, advantages, and disadvantages. Here are some of the most commonly used materials in sheet metal fabrication:

1. Steel: Steel is the most commonly used metal in sheet metal fabrication. It is a strong, durable, and cost-effective material that can be easily formed and welded. Steel is used to make a wide range of products, including automotive parts, appliances, and building materials.

2. Aluminum: Aluminum is a lightweight and corrosion-resistant metal, making it ideal for use in the aerospace, automotive, and construction industries. Aluminum is also readily available and easy to work with, making it a popular choice for sheet metal fabrication.

3. Copper: Copper is a highly conductive and corrosion-resistant metal that is often used in electrical and plumbing applications. It is also commonly used to make decorative objects and home furnishings.

4. Brass: Brass is a copper-based alloy that is often used in decorative applications due to its attractive golden color. It is also commonly used in the manufacture of musical instruments and plumbing fixtures.

5. Nickel: Nickel is a strong and corrosion-resistant metal that is often used in high-temperature applications, such as aerospace and industrial manufacturing. It is also used in the manufacture of coins and jewelry.

6. Titanium: Titanium is a lightweight, strong, and corrosion-resistant metal that is commonly used in the aerospace, military, and biomedical industries.

The choice of material used in sheet metal fabrication depends on the specific application, required properties of the finished product, and the cost.

Sheet metal typically refers to metal that is less than 6mm in thickness, while plate metal refers to metal that is 6mm or thicker.

Sheet metal bending and sheet metal folding are both methods of shaping sheet metal into various forms, but they differ in the way that the metal is manipulated.

Sheet Metal Bending: Sheet metal bending is a process of forming sheet metal into a desired shape by bending the metal around a straight axis, using a press brake machine. A press brake is a machine that consists of upper and lower dies, which clamp the sheet metal securely and apply pressure to bend the material to the desired angle.

The bending process generally produces a V-shape, U-shape, or channel-shape in the sheet metal. The bend radius and angle can be controlled precisely using specialized tooling and bending dies.

Sheet Metal Folding: Sheet metal folding, also known as edge bending, is a process of forming sheet metal using a folding machine. The folding machine bends the metal along a straight axis or a curved line, producing a crisp and clean fold. The fold is typically created using a punch and a die, which grip and bend the metal along a straight or curved line, creating a fold range that can be limited to 180°.

Sheet metal folding is ideal for producing shapes with folded edges such as panels with flanges or boxes.

The choice between sheet metal bending and sheet metal folding will depend on the specific requirements of the part, including the desired shape, bend angle, and production volume. For larger volumes or parts requiring more precise and complex bends, sheet metal bending is often the preferred choice, while sheet metal folding is ideal for parts with straight edges and simple bends.

The minimum bend radius for sheet metal depends on several factors, including the material thickness, the type of material, and the tooling used to make the bend. As a general rule, the minimum bend radius for sheet metal should be at least equal to the material thickness.

For example, if the sheet metal is 1 mm thick, then the minimum bend radius should be 1 mm. However, certain materials may require a larger bend radius due to their physical properties. Materials that are more brittle or have a greater yield strength may require a larger bend radius to prevent cracking or deformation.

The tooling used to make the bend also plays a critical role in determining the minimum bend radius. The punch and die used to make the bend should be designed with a radius that matches the minimum bend radius of the material, ensuring that the bend is consistent and does not cause damage to the metal.

It's important to note that the minimum bend radius is not the same as the maximum bend angle. The maximum bend angle for sheet metal is generally around 180 degrees, although this can vary depending on the thickness and type of material being used. The minimum bend radius is a key consideration in sheet metal bending to ensure that the bend is precise, consistent and does not result in defects in the finished part.