Introduction
Stamping, also known as pressing, is the process of placing flat sheet metal in either blank or coil form into a stamping press where a tool and die surface forms the metal into a net shape. Stamping includes a variety of sheet-metal forming manufacturing processes, such as punching using a machine press or stamping press, blanking, embossing, bending, flanging, and coining. This could be a single stage operation where every stroke of the press produces the desired form on the sheet metal part, or could occur through a series of stages. The process is usually carried out on sheet metal, but can also be used on other materials, such as polystyrene.
Types of Metal Stamping
1. Progressive Die Stamping: progressive stamping is the most automated form of metal stamping. This process involves using multiple slides on a press to feed and stamp slide-by-slide, which as a result can generate very complex parts in large quantities.
2. Fine Blanking: Fine blanking is a highly accurate and repeatable process that creates parts with smooth surfaces, tight tolerances, and flat surfaces without requiring secondary operations. Fine blanking produces parts with excellent surface finishes, and can be done in both thin and thick materials.
3. Transfer Stamping: Transfer stamping is a process that enables the production of complex parts that require multiple shapes and features. This process involves a press that moves the blank material into different machines that correspond to the desired shape and feature. The blank then moves to the next station, where it is further stamped, cut and trimmed to create the finished part.
4. Insert Molding: Insert molding is a process that allows for the assembly of components directly into a plastic part. The process requires specialized dies and fixtures which are designed to hold and inject the components into the mold cavity.
Material Selection
When selecting the best material for a stamping operation, the following criteria should be taken into consideration: Material strength, corrosion resistance, thermal conductivity, electrical conductivity, wear resistance, and formability. The material selected should be able to meet the mechanical and dimensional requirements of the application, as well as being cost efficient and reliable. Aluminium, copper alloys, mild steel, stainless steel, brass, and bronze are popular materials used in metal stamping operations.
Die Design Considerations
Designing a die is a complex task that requires consideration of the parts geometry and its manufacturing process. The die must be designed in such a way that the parts geometry is correctly formed and the tool has enough rigidity to withstand the forces generated during the stamping. Dies must also be designed to ensure that the parts produced by the stamping process have the desired dimensional accuracy and surface finish.
Safety Procedures
In metal stamping operations, safety must be given the highest priority. To ensure a safe working environment, it is important to understand the potential hazards associated with the process, and to take necessary measures to prevent injuries. The most common hazards include unguarded machines, materials that can fly off the press, hazardous noise levels, improper handling of sharp tools and materials, and heavy or awkward loads.
Conclusion
Metal stamping is a manufacturing process used to form sheet metal into parts with a desired shape and size. There are several types of metal stamping processes, such as transfer stamping, progressive die stamping, Fine blanking, and insert molding. It is important to select the right material and tooling for the desired application, and to take all necessary safety precautions when performing metal stamping operations.
