Metal stamping is one of the processes involved in the conversion of flat metal sheets into required or desired shapes. It is a manufacturing process that can produce a high volume of similar metal components. The stamping process is ideal for both short-term and long-term production. There are many manufacturing firms across the globe offering metal stamping service. Some of the components of metal stamping include:
- Punching and blanking- This simply refers to the use of a die to cut the metal into required forms. In this process, a scrap piece of the workpiece is removed to allow the punch to get some die. This ends up leaving a hole in the workpiece. Blanking involves getting rid of the workpiece from the primary material making the removed part the required workpiece.
- Coining- This is a bending technique whereby the metal is stamped when being placed between a press and die. Coining helps the punch tip penetrate the metal hence getting accurate and even repeatable bends. Deep coining helps in getting rid of the spring back effects of the workpiece.
- Bending- This is the overall technique of modeling meals into desired shapes. Some of the shapes include the U, V, and even the L. This process takes place around a single axis.
- Flagging- Flagging involves putting a flange or a flare onto a metal. This is done by the use of the dies, specialized flagging machinery, and even presses.
- Embossing- Embossing is the process of forming a raised or even a recessed design on a sheet of metal. This can also be achieved by passing material blank through a roller die.
Types of metal stamping processes
1. Progressive die stamping
Progressive die stamping is one of the processes that use a chain of stamping points. The process is suitable for long runs. This is because it uses a die that lasts for long without getting damaged. The process is also repeatable to save on the production cost. In these operations; a metallic coil is inserted into a spinning stamping press. Both the die and the press will move and when the press moves downwards, the die will close to stamp the metal and eventually form the part. If the press moves upwards, the metal will move horizontally to the next station. It is always advisable to ensure that the movements in the stations are aligned. This is because the metal part is still connected to the metal strip. The last station separates the newly created part from the entire part of the metal. Every station in the progressive die stamping process performs a different role or task. This helps in getting the desired metal shape and design at the end. The process is fast and there is minimal wastage of resources. This is because the amount of wasted scrap is less.
2. Transfer die stamping
In this process, the part is detached from the metal trip and moved from one stamping point to the next. A mechanical transport system for instance a conveyor belt is used to transfer the metal. The process is ideal for larger parts that need to be transferred to different presses.
3. Four-slide stamping
The four-side stamping is also known as the multi-slide or even four-way stamping. It is ideal for metals that have complex bends and twists. Four sliding tools are used in this operation. This helps to shape the workpiece through multiple deformations. Two slides are used to strike the workpiece horizontally. This helps in shaping the metal into the required shape and design. No dies are used in this operation. The process can also use more than four moving slides. Four–slide stamping is believed to be more versatile because different tools can be attached to it. It is a fast manufacturing process and also helps in saving the cost of production.
4. Fine blanking
The operation is also known as fine–edge blanking. It is ideal for producing smooth edges on metals without any fractures. Fine blanking is commonly done using the hydraulic or even the mechanical press. A combination of the two can also be used. The process entails three movements i.e. clamping the workpiece in place, the actual performance of the fine blanking task, and ejection of the finished part of the metal. The presses operate under higher pressures as compared to those used in conventional sampling operations. The operation is a single–step process. This helps reduce the overall cost of fabrication.
TYPES OF METAL STAMPING PRESSES
There are three commonly used metal stamping presses. The presses are linked to the automatic feeder that transfers sheet metal through the press either in blank or coil form. The stamping presses are the:
The hydraulic fluid is used in the hydraulic presses. This aids in applying energy to the material. The hydraulic pistons dislocate fluid with a force level proportionate to the piston front part. These aids in the regulation of pressure. These presses also entail adjustable stroke and speed capabilities. They come in different sizes ranging from twenty to 10000 tons and they also offer stroke sizes from approximately 10mm to 800mm. These types of presses are commonly used in short production runs to create deeper stampings. They also create room for flexibility because they contain adjustable stroke length and even controlled pressure.
2) Mechanical servo
The mechanical servo presses use high-capacity motors. They are commonly used to create more complicated stampings at a faster speed as compared to hydraulic ones. The slide position, speed, motion, and even stroke are regulated and programmed. These presses can either be powered by link- assisted drive system or even a direct drive system. Though they are quite expensive, there are believed to give out excellent results.
They use a motor-connected flywheel to help in the storage and transfer of energy. The punches in these presses come in different sizes ranging from 5mm to 500mm. They also have strokes ranging from 20 and 1500 per minute. They are well designed to come up with shallower and simpler parts from the coils of the metal sheet. Mechanical presses are commonly used in progressive stamping and transfer stamping operations. This is because they are strong enough to be used in the long–run production.
To sum up, metal stamping involves innumerable operations. The above article illustrates some of the operations and the presses used to get the desired metal shape and design.