Stamping process

Numerous cold-forming processes in the manufacturing industry manipulate the metal sheets into the desired shape at room temperature. The standard cold-forming techniques include stamping, forging, extruding, rolling, and drawing. These are the straightforward and cost-effective approaches in sheet metal fabrications.

Metal stamping is the most popular cold-forming technique in sheet metal works and is used for several applications, including automotive, electronics, aerospace, telecommunication, and many more. This article will briefly discuss the stamping materials, procedure, types, and applications to enhance your understanding of the stamping process.

 

What is Metal Stamping?

Metal stamping is a manufacturing approach that converts coils or sheets of metal into desired geometry with the help of pressure and dies of the desired shape. The stamping die is the pre-engineered tool, which feeds the material into it and converts it to the intended form by applying pressure. It allows for the mass production of metallic parts with excellent repeatability. Metal stamping has become more industrialized with optimizing processes, systems, and tools (Carl-Johan Jonsson, 2021).

The pressure machine, stamping die, and punch are three significant components in the stamping process. A specific die is required for a particular part, which is mounted into presses, and metal is fed to create the shape.

You might think that the metal sheet produces the required shape and scrap in the die-stamping process, but that is not true in all cases. For example, a sheet metal piece can be converted into a U-shape part without leaving any scrap by feeding and pressing through a die.

Depending on the intricacy of the component, it may take numerous steps to make each part, including punching, blanking, embossing, flanging, and bending.

 

Which Materials Can Be Processed with Stamping?

Metal stamping is suitable for metallic elements and some plastics & composites as well. The following are the common materials used in stamping; for more information, please check our material page;

• Steel
• Aluminium
• Copper
• Brass
• Titanium
• Nickel-chromium alloys
• Polystyrene
• Polypropylene
• ABS
• Carbon fiber
• Aramid fibers

 

Types of Metal Stamping Processes

Based on the standard stamping practices, there are four processes: progressive die, four slides, deep draw, and short-run stamping.

1. Progressive die stamping

Progressive die stamping

As the name suggested, progressive stamping refers to applying a series of different dies in a single fed. The sheet metal is fed through the first die that performs the first operation, such as punching or cutting. Then, it moves to the next die, which serves the next operation, and so on, until the final product is created.

Since different stamping operations can be performed simultaneously in a single process, it allows for the production of complex parts with multiple features, such as holes, slots, and bends. Another significant advantage is that progressive die stamping is quick & less labor intensive, reducing overall manufacturing costs.

2. Four-slide stamping

Four-slide stamping machine

The four-sliding stamping process refers to multiple metal stamping operations, such as punching, bending, and forming, on a single piece of metal in a single operation. It is done by a specialized machine called “four slide or multi-slide press.” The device consists of four adjustable slides (or tooling stations to perform different operations. The worksheet is fed into the machine and moved between the slides, which serve the stamping operations in succession. It can be easily reconfigured to produce parts with different shapes and features.

This process is ideal for small to medium-volume production runs and is commonly used to produce small, complex parts with tight tolerances.

3. Deep draw stamping

Concept of deep draw stamping (Li, 2022)

The deep draw stamping process involves pressing sheet metal into a die by a punch. The punch forces the metal to flow and form a deep or complex part, exactly like the shape of the dice.

The deep draw stamping begins with clamping the worksheet blank into a holder, known as a “blank holder,” which surrounds the punch. As the punch descends into the die, it pushes the worksheet blank into the die, forcing the metal to flow and conform to the shape of the die. This process is suitable for creating deep or complex geometries with uniform thicknesses, such as cans, cups, and containers.

4. Short run stamping

Short-run stamping involves producing a small number of metal parts (usually between 1 and 1000) in a single run. It is accomplished using various 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. Short-run production is typically used to produce parts for prototyping, testing, or small-scale production runs, facilitating the production of a small volume of parts at a relatively low cost.

 

What Are the Different Stamping Operations

Several metal stamping operations are manufactured based on the requirements and intended shape. Some involve cutting the materials (scrap as a by-product), and some are non-cutting (Do not create scrap from the worksheet). However, they all include pressing the worksheet in a die to create the shape.

Bending	The process of bending is relatively easy to understand. The worksheet is inserted into a specific die and pressed with a ram or a press brake to create the desired bend angle through the deformation.
Blanking	In the blanking, the punch-out pieces are the final product. It begins with aligning a punch and die with the blank. The punch hits the die and cuts the sheet metal into the correct shape. The process is complete when the part is completely cut out.
Piercing	Piercing is punching small holes, slots, or cut-outs using a punch press. The piercing die holds the workpiece, and the punch descends into the die, cutting or punching a hole into the sheet metal.
Drawing	Drawing is another type of metal stamping involving pulling a sheet metal through a die to produce a specific shape or form. It is performed using a draw press that uses a powerful ram to exert a pulling force on the sheet metal.
Embossing	Embossing is creating raised surfaces on the metal sheet using a punch and die. The punch contains the negative image of the required shape, which is then pressed into the sheet metal, leaving a raised or depressed image on the surface.
Coining	As the name suggested, coining refers to the shaping of sheet metal for the features of a coin. The worksheet gets imprinted in the desired area using two dies, pressing against each other on opposite sides of the worksheet.
Lancing	Lancing does not create any scrap material after the operation. In this operation, the workpiece is sheared and bent with one die strike. It creates slots, notches, or other features in sheet metal.
Curling	Curing refers to deforming a sheet metal into a tubular shape or profile, such as door hinges. This process is typically carried out using a specialized tool or machine, such as a curling machine or a press brake.
Hemming	Sheet metal hemming involves folding an edge of sheet metal onto itself to add thickness to the edge.
Flanging	Flanging refers to the bending of the material along a curved line. It involves applying pressure to one or more specific areas of the sheet metal, causing it to bend and form along a curved line.

All these metal stamping operations are popular because of low cost, quick production, complex-shapes capability, and accuracy. The stamping can provide tolerance ranges from ±0.125 mm to ±1.5 mm (Zhang).

 

 

The Costs of Stamping Process

Typically, stamping costs are lower than other metal forming processes as it does not require fabricating the parts differently and assembling them for the final part or product. Instead, sheet metal stamping creates the end part with a single cycle, followed by trimming or other post-processing.

However, the exact cost of stamping depends on the specifications of your particular design, such as sheet metal material, precision, production volume, etc. The following are the common factors influencing the cost.

Material type: Eg. Aluminum is cheaper than brass and copper.
Required precision: Tight tolerance requirements increase the stamping cost.
Production Volume: Large-scale production costs significantly less ( per par price) than small batches.
Complexity: Due to intricate die design and longer production cycles, complex stamping parts cost more.

 

Applications of Stamping Process

Parts created with stamping.

Stamping parts and products are everywhere, from our daily appliances and kitchenware to advanced aerospace parts. The quick, straightforward procedure, low cost, and accuracy make it suitable for different automotive, aerospace, and electronics applications.

Industry	Applications
Automotive	The automotive industry has a significant role in the evolution of stamping technology. It was initially developed to manufacture various automotive parts, and now it is in the automation and computer control stage. The common parts in automotive that use the stamping process are body panels, engine parts, transmission parts, suspension components, interior, and many more.
Electronics	Connectors, switches, enclosures, relays, transformer core, and more.
Aerospace	The stamping process produces various aerospace components, such as airframe parts, engine components, wheels, brakes, seats, cabin walls, and fluid system components.
Home appliances	Washing machine drums, refrigerator door liners, oven racks, microwave plates, blender blades, coffee maker filters, and more.
Military & defense	Armor plates, helmets, magazines, triggers, antenna, connectors, navigation systems, and targeting systems.
Medical	Scalpel blades, forceps, pacemakers, artificial joints, medical tubing, braces, splints, dental crowns, medical sensors, microscopes, centrifuges, stethoscopes, artificial heart valves, artificial tendons, and many more.

 

Conclusion

Metal stamping is a popular cold-forming technique in sheet metal works, which is used to convert coils or sheets of metal into desired geometry with the help of pressure and dies of the desired shape. This process allows for the mass production of metallic parts with excellent repeatability and is used in various industries such as automotive, electronics, aerospace, and telecommunication.

The design and creation of appropriate die are essential to creating accurate stamped parts. ProleanTech has all the expertise related to stamping services. We have experienced engineers to design the die and automated pressing machines to execute the various custom metal stamping operations. If you need any stamping services, request a quote, and we will get back with all details within an hour.

 

FAQ’s

What are the components of the metal stamping process?

The pressure machine, stamping die, and punch are three major components in the stamping process. A specific die is required for a particular part, which is mounted into presses, and metal is fed to create the shape.

What are the different types of metal stamping processes?

The different types of stamping processes include Progressive die stamping, Four slide stamping, Deep draw stamping, and Short run stamping.

What are the materials that can be processed with stamping?

The most common materials that can be processed with stamping are Steel, Aluminum, Brass, Copper, Titanium, Stainless steel and Nickel-chromium alloys, Polystyrene, Polypropylene, Polycarbonate, Fiberglass, Carbon fiber, and others.

What are the common industries that use the metal stamping process?

The metal stamping process is used in various automotive, electronics, aerospace, and telecommunication industries. It is also used to produce various household appliances and medical equipment.

 

References

1. Carl-Johan Jonsson, R. S. (2021). Stamping Tools for Sheet Metal Forming: Current State and Future Research Directions. IOS Press Ebooks, from https://ebooks.iospress.nl/.
2. Li, S. (2022). Sheet Metal Deep Drawing for Making Metallic Parts and Structures. Encyclopedia of Materials: Metals and Alloys.
3. Zhang, J. (n.d.). Stamping Design Guidelines. from http://bowmannz.com/.