Many cold forming processes in the manufacturing industry form sheet metal into the desired shape at room temperature. Standard cold forming techniques include stamping, forging, extrusion, rolling, and drawing. These are straightforward and cost-effective methods of sheet metal processing.
Metal stamping is the most popular cold forming technique in sheet metal processing and is used in a variety of applications such as automotive, electronics, aerospace, telecommunications, etc. This article will briefly discuss stamping materials, procedures, types, and applications to enhance your understanding of the stamping process.
Metal stamping is a manufacturing method that uses pressure and dies of the desired shape to transform a metal coil or sheet into the desired geometry. A stamping die is a pre-designed tool that feeds the material into the die and transforms it into the desired shape by applying pressure. It allows for mass production of metal parts with excellent repeatability. Metal stamping has become more industrialized as processes, systems, and tools have been optimized.
The press, stamping die, and punch are three important components in the stamping process. A specific part requires a specific die, which is installed into the press and then fed with metal to form the shape.
You might think that sheet metal produces the desired shape and waste during the die stamping process, but this is not true in all cases. For example, a sheet metal part can be converted into a U-shaped part without any waste by feeding and pressing with a die.
Depending on the complexity of the part, many steps may be required to manufacture each part, including punching, blanking, embossing, flanging, and bending.
Metal stamping is suitable for metal components as well as some plastics and composite materials. The following are common materials used in stamping：
· Iron plate
· Aluminum
· Cooper
· Brass
· Titanium
· Nickel-chromium alloy
· Polystyrene
· Polypropylene
· ABS
· Carbon fiber
· Aramid fiber
Types of Metal Stamping Processes
According to standard stamping practices, there are four processes: progressive die, four-slide, deep draw, and short run stamping.
1. Progressive die stamping
As the name implies, progressive stamping involves the application of a series of different dies in one feed. The sheet metal is fed into the first die which performs the first operation, such as punching or cutting. It then moves to the next die which serves the next operation, and so on, until the final product is created.
Because different stamping operations can be performed simultaneously in one process, complex parts with multiple features, such as holes, slots, and bends, can be produced. Another significant advantage is that progressive die stamping is fast and less labor-intensive, which reduces overall manufacturing costs.
The four-slide stamping process involves performing multiple metal stamping operations such as punching, bending, and forming on a piece of metal in a single operation. It is performed by a specialized machine called a "four-slide or multi-slide press." This equipment consists of four adjustable slides (or tool stations) that are used to perform different operations. The work piece is fed into the machine and moved between the slides, which are used in turn for stamping operations. It can be easily reconfigured to produce parts with different shapes and features.
The process is well suited for small to medium-volume production and is often used to produce small, complex parts with tight tolerances.
The deep draw stamping process involves pressing a metal sheet into a die by means of a punch. The punch forces the metal to flow and form deep or complex parts, like the shape of a dice.
Deep draw stamping begins by clamping the work sheet into a fixture, called a holder. As the punch descends into the die, it pushes the work sheet blank into the die, forcing the metal to flow and conform to the shape of the die. The process is suitable for making deep or complex geometries with uniform thickness, such as cans, cups, and containers.
Low-volume stamping involves producing a small number of metal parts (usually between 1 and 1,000) in a single run. It can be done through a variety of methods, including progressive stamping, four-slide stamping, and deep-draw stamping.
However, the process uses automatic or semi-automatic machines such as punch presses and shears. Low-volume production is often used to produce parts for prototyping, testing, or small-scale production, helping to produce a small number of parts at a relatively low cost.
There are a number of metal stamping operations that can be performed depending on the requirements and the desired shape. Some involve cutting the material (with scrap as a byproduct) and some do not (no scrap is generated from the work sheet). However, they all involve pressing the work sheet in a die to form the shape.
• Bending: The process of bending is relatively easy to understand. The sheet is inserted into a specific die and pressed with a punch or a press brake to produce the desired bend angle through deformation.
• Blanking: In the blanking process, the punched piece is the final product. The punch and die are first aligned with the blank. The punch strikes the die and cuts the sheet metal into the correct shape. The process is complete when the part is completely cut out.
• Piercing: Punching is the use of a punch press to create a small hole, slot, or cutout. The punching die holds the workpiece and the punch is lowered into the die to cut or punch a hole in the sheet metal.
• Drawing: Drawing is another type of metal stamping that involves pulling the sheet metal through a die to produce a specific shape or form. It is performed using a drawing press, which uses a powerful punch to apply a pulling force to the sheet metal.
• Embossing: Embossing is the process of creating a raised surface on a sheet of metal using a punch and die. The punch contains a negative image of the desired shape, which is then pressed into the sheet metal, leaving a raised or depressed image on the surface.
• Casting: As the name implies, casting is the process of shaping a sheet of metal into features that resemble a coin. The sheet is embossed in the desired area using two dies pressed against each other on opposite sides of the sheet.
• Punching: Punching does not produce any waste material after the operation. In this operation, the workpiece is sheared and bent with a single die strike. It creates slots, notches, or other features in the sheet metal.
• Curling: Curling is the process of deforming a sheet of metal into a tubular shape or profile, such as a door hinge. This process is usually performed using specialized tools or machines, such as a curling machine or a press brake.
• Flanging: Flanging involves folding the edge of a sheet of metal over to increase the thickness of the edge.
• Curling: Flanging is the bending of material along a curve. It involves applying pressure to one or more specific areas of a sheet of metal to cause it to bend and form along a curve.
All of these metal stamping operations are popular due to low cost, fast production, complex shapes and high precision. Stamping can provide tolerances ranging from ±0.125 mm to ±1.5 mm (sheet).
Typically, stamping costs less than other metal forming processes because it does not require parts to be manufactured in different ways and assembled into a final part or product. Instead, sheet metal stamping requires only one cycle to create the final part, followed by trimming or other post-processing.
However, the specific cost of stamping depends on the specifications of your particular design, such as sheet metal material, precision, production volume, etc. The following are common factors that affect cost.
Material Type: For example, aluminum is cheaper than brass and copper.
Required Precision: Tight tolerance requirements increase the cost of stamping.
Production Volume: The cost (per piece price) of large-scale production is significantly lower than that of small-scale production.
Complexity: Complex stampings are more expensive due to complex die design and longer production cycles.
From our daily utensils, kitchenware to advanced aerospace parts, stamping parts and products are everywhere. The fast, simple process, low cost and accuracy make it suitable for different automotive, aerospace and electronics applications.
· Automotive Industry: The automotive industry has played an important role in the development of stamping technology. Initially developed to manufacture various automotive parts, it is now in the stage of automation and computer control. Common parts in automobiles that use stamping process are body panels, engine parts, transmission parts, suspension parts, interior decoration, etc.
· Electronic Industry: Connectors, switches, housings, relays, transformer cores, etc.
· Aerospace: Stamping process can produce various aerospace parts such as fuselage parts, engine parts, wheels, brakes, seats, cabin walls and fluid system parts
· Home Appliances: Washing machine drum, refrigerator door lining, oven rack, microwave plate, blender blade, coffee machine filter, etc.
· Military & Defense: Armor plates, helmets, magazines, triggers, antennas, connectors, navigation systems and aiming systems.
· Medical industry: surgical blades, tweezers, pacemakers, artificial joints, medical tubing, braces, splints, crowns, medical sensors, microscopes, centrifuges, stethoscopes, artificial heart valves, artificial tendons, etc.
Metal stamping is a common cold forming technique in sheet metal processing that uses pressure and a die of the desired shape to convert a metal coil or sheet into the desired geometry. The process can mass produce metal parts with excellent repeatability and is used in various industries such as automotive, electronics, aerospace, and telecommunications.
Designing and manufacturing the right die is essential to making accurate stamped parts. JWB has all the expertise related to stamping services. We have experienced engineers to design the dies and automatic presses to perform a variety of custom metal stamping operations. If you need any stamping services, request a quote and we will respond with all the details within an hour.
