Sheet Metal stamping is a cold-forming process that uses dies and stamping pressing machines to shape sheet metal into various forms. Pieces of flat sheet metal typically referred to as blanks, are fed into a sheet metal stamping press that uses a tool and dies surface to transform the metal into a new shape. The material is placed to be stamped between die sections, where the use of pressure will form and shear the material into the desired final shape for the product or component.
Types of Stamping Operations
progressive stamping process uses a type of tooling called a progressive die, which contains multiple stamping stations to carry out simultaneous operations on a sheet metal strip. By combining all the necessary tools into one die set, progressive die stamping is a great solution for high-volume production runs.
Transfer die stamping is similar to progressive die stamping, but the part is separated from the metal trip early on in the process and is transferred from one stamping station to the next by another mechanical transport system, such as a conveyor belt. This process is usually used on larger parts that may need to be transferred to different presses.
Four-slide stamping is also called multi-slide or four-way stamping. This technique is best-suited for crafting complex components that have numerous bends or twists. It uses four sliding tools, instead of one vertical slide, to shape the workpiece through multiple deformations. Two slides, or rams, strike the workpiece horizontally to shape it, and no dies are used. Multi-slide stamping can also have more than four moving slides.
Four-slide stamping is a very versatile type of stamping, as different tools can be attached to each slide. It also has a relatively low cost, and production is fast.
Fine blanking, also known as fine-edge blanking, is valuable for providing high accuracy and smooth edges. Usually done on a hydraulic or mechanical press, or by a combination of the two, fine blanking operations consist of three distinct movements:
Fine blanking presses operate at higher pressures than those used in conventional stamping operations, hence tools and machinery need to be designed with these higher operating pressures in mind.
The edges produced from fine blanking avoid fractures as produced with conventional tooling and surface flatness can exceed that of other stamping methods. Since it is a cold extrusion technique, fine blanking is a single-step process, reducing the overall costs of fabrication.
Deep drawing involves pulling a sheet metal blank into the die via a punch, forming it into a shape. The method is referred to as “deep drawing” when the depth of the drawn part exceeds its diameter. This type of forming is ideal for creating components that need several series of diameters and is a cost-effective alternative to turning processes, which typically require using up more raw materials. Common applications and products made from deep drawing include:
Short-run stamping sheet metal product requires minimal upfront tooling expenses and can be an ideal solution for prototypes or small projects. After the blank is created, manufacturers use a combination of custom tooling components and die inserts to bend, punch or drill the part. The custom forming operations and smaller run size can result in a higher per-piece charge, but the absence of tooling costs can make short-run more cost-efficient for many projects, especially those requiring fast turnaround.
Stamping Advantages and Disadvantages
Stamping metal parts sheet metal fabrication has several advantages including lower die costs, lower secondary costs, and a high level of automation compared to other processes. Metal stamping dies are less costly to make and maintain than dies used in other typical operations. Cleaning and plating are also less expensive than identical treatments for other metal manufacturing techniques. Stamping machines are generally simple to automate and may use sophisticated computer-control systems to give more precision, faster output, and shorter turnaround times. The high level of automation also reduces labor costs.
One of the disadvantages of stamping is the higher cost of presses. The dies must also be acquired or created and producing custom sheet metal stamping dies is a longer pre-production process. Dies can also be difficult to change if the design must be altered during production.