sheet metal fabrication

1. Bending is a process by which metal can be deformed by plastically deforming the material and changing its shape. The material is stressed beyond the yield strength but below the ultimate tensile strength. The surface area of the material does not change much. Bending usually refers to deformation about one axis. 2. Laser cutting machines can accurately produce complex exterior contours. The laser beam is typically 0.2 mm (0.008 in) diameter at the cutting surface with a power of 1000 to 2000 watts. Laser cutting can be complementary to the CNC/Turret process. The CNC/Turret process can produce internal features such as holes readily whereas the laser cutting process can produce external complex features easily. Laser cutting takes direct input in the form of electronic data from a CAD drawing to produce flat form parts of great complexity. With 3-axis control, the laser cutting process can profile parts after they have been formed on the CNC/Turret process. Lasers work best on materials such as carbon steel or stainless steels. Metals such as aluminum and copper alloys are more difficult to cut due to their ability to reflect the light as well as absorb and conduct heat. This requires lasers that are more powerful. 3. The Computer Numerical Control (CNC) fabrication process offers flexible manufacturing runs without high capital expenditure dies and stamping presses. High volumes are not required to justify the use of this equipment. Tooling is mounted on a turret which can be as little as 10 sets to as much as 100 sets. This turret is mounted on the upper part of the press, which can range in capacity from 10 tons to 100 tons in capacity. The turret travels on lead screws, which travel in the X and Y direction and are computer controlled. Alternatively, the workpiece can travel on the lead screws, and move relative to the fixed turret. The tooling is located over the sheet metal, the punch is activated, and performs the operation, and the turret is indexed to the next location of the workpiece. After the first stage of tooling is deployed over the entire workpiece, the second stage is rotated into place and the whole process is repeated. This entire process is repeated until all the tooling positions of the turret are deployed. 4. Welding is the process of permanently joining two or more metal parts, by melting both materials. The molten materials quickly cool, and the two metals are permanently bonded. Spot welding and seam welding are two very popular methods used for sheet metal parts. Spot welding is primarily used for joining parts that normally upto 3 mm (0.125 in) thickness. Spot-weld diameters range from 3 mm to 12.5 mm (0.125 to 0.5 in) in diameter. 5. Welding is the process of permanently joining two or more metal parts, by melting both materials. The molten materials quickly cool, and the two metals are permanently bonded. Spot welding and seam welding are two very popular methods used for sheet metal parts. Spot welding is primarily used for joining parts that normally upto 3 mm (0.125 in) thickness. Spot-weld diameters range from 3 mm to 12.5 mm (0.125 to 0.5 in) in diameter. 6. The operations associated with stamping are blanking, piercing, forming, and drawing. These operations are done with dedicated tooling also known as hard tooling. This type of tooling is used to make high volume parts of one configuration of part design. (By contrast, soft tooling is used in processes such as CNC turret presses, laser profilers and press brakes). All these operations can be done either at a single die station or multiple die stations performing a progression of operations, known as a progressive die.