Sheet Metal Stamping Process: The Complete Guide

Companies dealing with specialized equipment need parts that aren’t readily available on the market. Sheet metal stamping involves bending, shaping, and cutting the material to produce these unique parts. Read this guide to understand how sheet metal stamping works and how it relates to the manufacturing process.

What Is Sheet Metal Stamping?

Sheet metal stamping is a cold-forming process that employs speed or extreme force to change the shape of the piece of metal permanently. It involves feeding metal into the press tool, where the stamping tool (die) creates the desired shape.

Sheet Metal Stamping Materials

Metal stamping is probably the most popular manufacturing process today. It involves punching, perforating, embossing, or tooling carefully selected sheet metal materials to produce complex valuable parts. However, transforming metal sheets into functional parts isn’t limited to shape and design. Manufacturers must use the most appropriate raw materials for each part to make it work.

Common materials used are:

Sheet Metal Stamping Materials

Forming Technique In Sheet Metal Stamping

Forming Technique In Sheet Metal Stamping
Forming Technique In Sheet Metal Stamping

Sheet metal stamping is the most effective and low-cost way to produce a high volume of identical metal parts. This process can be employed for short and long-term production goals, especially when combined with other metal fabrication techniques.

Metal stamping consists of one or more techniques designed to achieve different results. Popular techniques include:

  • Blanking
  • Drawing
  • Piercing
  • Coining
  • Embossing
  • Bending

Blanking and punching employ the same principles when shaping metals. They both use a die to cut the material into a specific form.

However, there is a slight difference between the two.

In blanking, the manufacturer removes a workpiece from the raw material, making the removed piece the desired blank.

On the other hand, in sheet metal punching, the manufacturer uses the die to punch holes into the workpiece.

Manufacturers use embossing to create raised or recessed designs on sheet metal. This technique involves passing the material blank through a roller die or pressing the blank material against a die with the desired shape.

Flanging works similarly to embossing as it involves introducing flanges or flares onto the sheet metal.

This technique uses specialized flanging machinery, die, or press to realize the desired design.

Bending is arguably the most common technique to form metal into specific shapes, including L, U, and V-shaped profiles.

It occurs around a single axis, resulting in plastic deformation at the yield point but below the tensile strength.

Bending has close similarities to coining, where the sheet metal is placed between a die and the press. This cause the punch tip to penetrate the metal, resulting in accurate, repeatable bends.

Most metal stamping machines are designed to do more than stamping. They are also used to cut, punch, cast, and shape metal sheets.

The machines are programmed, or computer numerically controlled to ensure precision and repeatability.

To meet specific stamping needs, you can also use various tooling machines, including forming, compound, progressing, and carbide tools. For example, advanced tools create multiple pieces on a single workpiece at once.

Blanking Process In Sheet Metal Stamping

Blanking Process In Sheet Metal Stamping
Blanking Process In Sheet Metal Stamping

The blanking technique draws its name from the punched-out piece of metal, blank, formed from cutting specific shapes from raw materials. This action is done using a die made from hardened steel or carbide.

Sheet metal blanking is often effective on raw materials such as stainless steel, aluminum, carbon steel, and plastic.

This technique is relatively quick and cost-effective, hence its popularity in the industry. However, it’s advisable to consider a few factors before fully implementing them.

Despite being the best option for large-scale production, most pieces may come out with cracks and burrs on the edges. However, these issues are resolved using high-quality tools and post-processing the blanks.

Types of Blanking

The principles behind blanking are relatively simple. However, there are several variations to the technique.

Continuous strip blanking

This technique involves feeding the raw materials into the stamping machine. The machine then alters the shape of the material into specific forms.

The best part is that it produces several identical shapes, making it the best method for making medallions, bottle caps, and coins, among many others.

Square sheared blanking

This process utilizes a delicate process featuring specialized clamping tools designed to produce contoured or square-edged blanks.

Squared sheared blanking is often used to make casings, panels, and any part that requires a uniform square shape.

Cutoff

Cutoff combines metal cutting with blanking to create specialized blanks. This technique involves blanking the sheet metal before cutting the metal to produce long, flat pieces.

Drawing Techniques In Sheet Metal Stamping

Drawing Techniques In Sheet Metal Stamping
Drawing Techniques In Sheet Metal Stamping

The drawing technique uses tensile forces to stretch the raw material.

As the metal sheet is drawn, it becomes thinner, achieving the desired shape and thickness.

Manufacturers can either use sheet metal drawing or wire, bar, or tube drawing to form the metal sheets into specific shapes.

Sheet metal drawing occurs through plastic deformation over a curved axis. Tube, wire, and bar drawing uses a die to reduce the diameter, increase its length and achieve the desired size.

Drawing is a cold-working process since most work is done at room temperature. However, manufacturers use high temperatures to hot-work large raw materials and reduce forces.

Types of Sheet Metal Drawing

Cold drawing

This technique involves stretching and pulling metal at room temperature.

Cold drawing is arguably one of the most effective techniques for manipulating metal shapes with great accuracy. The best part is that you can form metal while preserving the metal’s strength and physical properties.

Sheet metal drawing

This technique is used to produce sheet metals.

It involves applying pressure to the blank while the drawing machine pulls the metal into the desired shape and size.

For sheet metal drawing to be effective, you need to apply the correct pressure—insufficient pressure results in thick sheets that are difficult to form.

Deep drawing

This technique is similar to sheet metal drawing; however, it stretches the metal longer than its diameter.

Sheet metal deep drawing is relatively complex and requires special attention when using the mechanical punch. The punch forces the metal sheet to take the die’s shape.

Piercing Technique In Sheet Metal Stamping

Piercing Technique In Sheet Metal Stamping
Piercing Technique In Sheet Metal Stamping

The piercing technique uses a punch and dies to create holes in sheet metal or raw material. The machine and process are similar to those used in blanking, with the difference being the workpiece.

In piercing, the workpiece used is a scrap.

There are several techniques for piercing, including perforating, lancing, dinking, cutoff, shaving, and nibbling.

Unlike other techniques, piercing requires a lot of clearance. However, the clearance amount depends on the raw material’s thickness and strength.

Remember that excessive point pressure could lead to accelerated wear and failure of the workpiece.

Types of Piercing Techniques

Lancing

This technique involves shearing and bending the workpiece to form tabs, vents, and louvers.

Lancing is characterized by reducing the material by modifying its geometry.

One or more cuts are made during lancing, with the remaining piece bent or curved to realize a specific shape.

Nibbling

Nibbling involves cutting contours onto the workpiece to produce a series of overlapping notches or slits.

This technique forms complex shapes of up to 6mm in thickness.

Manufacturers mainly use the nibbler for this technique, a die, and a small punch that reciprocates 300-900 per minute. These machines come in various shapes and sizes and can be used for exterior and interior cuts.

Shaving

Shaving is often used as a finishing technique where small amounts of metal are sheared from the blanked workpiece. It’s used to provide better accuracy with the secondary purpose of squaring and smoothing the edges.

Cutoff

Manufacturers employ this technique to separate a stamping from stock or strip. It’s used chiefly with progressive die sequences. The cutoff process is perfect for outlining the periphery counter on the workpiece.

Coining Techniques In Sheet Metal Stamping

Coining Techniques In Sheet Metal Stamping
Coining Techniques In Sheet Metal Stamping

Coining is a bending technique where the metal sheet is placed between a punch, press, and die, then stamped.

Here, the punch tip penetrates the workpiece creating accurate, repeatable bends while relieving the internal stress on the workpiece.

Manufacturers prefer this technique for its beneficial properties in some metals.

When applied to specific raw materials, the plastic flow reduces the surface grain size and hardens the surface while retaining internal toughness and ductility.

Coining has numerous applications across multiple applications, especially where there is a need for fine features.

Typical applications include making springs, coins, buttons, and precision sheet metal parts.

Coining has several advantages, including reducing the inside radius to the smallest possible size and high repeatability.

Unlike most techniques, coining doesn’t require CNC machines to form shapes.

However, it requires more tonnage compared to most, at least 5-8 times more for bottom bending.

Due to the extra tonnage, manufacturers must install high-quality tools to ensure long-term service and efficiency.

Embossing Technique In Sheet Metal Stamping

Embossing Technique In Sheet Metal Stamping
Embossing Technique In Sheet Metal Stamping

The embossing technique produces raised or sunken designs on metal sheets.

You can pass the metal sheet between rolls with the desired patterns or use matched male and female roller dies.

Manufacturers often combine this technique with foil stamping to create a shiny 3D effect on the workpiece.

Unlike most techniques, embossing combines heat and pressure to produce desired patterns.

Embossing is designed to alter the shape and thickness of the metal sheet.

For example, in pressure embossing, the bottom roll blocks are movable while the upper blocks remain stationary.

Embossing machines are generally limited to embossing since they are custom to fit specific needs. These machines are designed to produce patterns not less than 6 inches wide and a maximum of 70 inches wide.

This technique has numerous benefits, including the ability to form ductile metals using medium to high production runs.

The best part is that it can produce unlimited patterns depending on the roll dies and reproduce the product with no variation.

Bending Technique In Sheet Metal Stamping

Bending Technique In Sheet Metal Stamping
Bending Technique In Sheet Metal Stamping

Sheet metal bending is arguably the most popular stamping technique.

It involves applying force to a workpiece to alter its geometry. When carefully applied, the pressure causes stress to the metal sheet to the yield point, changing its physical shape without breaking.

Most manufacturers use a press brake to punch onto a sheet metal positioned on a die to create the desired form.

Bending may seem like a straightforward process, but it has different methods. Below are examples of the bending process;

V-bending

This is the most common method featuring a V-shaped die and punches to bend metals to desired shapes.

V-bending allows you to bend the workpiece to a specific, obtuse, acute, or 90 degrees, depending on your desired angle.

Air bending

Air bending works similarly to v-bending with a slight difference.

Here, the punch machines don’t force the workpiece to the bottom of the cavity; instead, it leaves room beneath for better angle control.

Roll bending

This technique allows you to bend the metal sheets into rolls, tubes, cones, or any curved shape. Roll bending uses a set of rollers that feed the workpiece to the desired curvature.

Types Of Sheet Metal Stamping Operations

Progressive Die Stamping Sheet Metal
Progressive Die Stamping Sheet Metal

Progressive die stamping features a sequence of stamping stations with a metal coil fed into a reciprocating stamping press or punch.

This operation utilizes progressive stamping dies that move with the press to stamp the metal and form the desired shape. It is ideal for long runs due to repeatability and durability.

Transfer Die Stamping Sheet Metal
Transfer Die Stamping Sheet Metal

Transfer die stamping follows the same procedure as progressive die stamping.

However, in this case, the workpiece is separated from the metal strip and transferred to another stamping station using a mechanical transport system.

Four Slide Stamping Sheet Metal
Four Slide Stamping Sheet Metal

Four-slide stamping is a four-way stamping operation used for crafting complex components with several ends and twists.

It uses four sliding tools to shape the raw material into multiple forms.

Multi-slide stamping can be fitted with more than four moving slides, depending on the desired shape.

Compound Stamping Sheet Metal
Compound Stamping Sheet Metal

The die is programmed to perform multiple functions, including bending, punching, and cutting in one downward stroke. The workpiece is fed into the stamper with the end product ejected from the metal strip.

This operation creates multiple cuts and holes in one workpiece without performing multiple strokes or switching dies.

Applications Of Sheet Metal Stamping Process

Automotive
Automotive

This process is one of the critical elements in the automotive industry used to reduce the waste of raw materials and promote productivity. It’s mainly used to make automobile chassis, interior and exterior structural components, and transmission components.

Electronics

This process is used in the electronics industry to make precise, detailed, and identical parts. The best part is that manufacturers can leverage advanced techniques to make even the smallest components vital to the electronics industry.

Telecommunication
Telecommunication

Sheet metal stamping offers precision and repeatability, which is vital in producing components in the telecommunications industry. Stamping is used to make various components, including automotive lighting systems, robots, smart plugs, and power strips.

Aerospace
Aerospace

Like most niche industries, aerospace requires metal stamping to make various components. These include airplane body frames, engines, and even small parts.

People Also Ask:

What Is Precision Sheet Metal Stamping?

Precision sheet metal stamping is a manufacturing process that uses a custom die and tool installed in a stamping press to transform metal sheets into desired forms. It produces large quantities of parts with high accuracy, speed, and precision.

Which Are The Main Sheet Metal Stamping Tools And Equipment?

There are several types of metal stamping tools and equipment. However, typical examples include the punch press, turret, and brake press. Depending on your needs, you can also find dies in various shapes and sizes.

How Does Hydroforming And Sheet Metal Stamping Compare?

Hydroforming is one of the best techniques for complex or asymmetrical shapes.

It offers unparalleled flexibility and precision and is relatively cost-effective.

On the other hand, sheet metal stamping is a traditional technique used to mass-produce large components.

How Do You Choose Dies For Sheet Metal Stamping Process?

Stamping dies are designed and developed using computer-aided designs to ensure precision and accuracy before production by skilled artisans.

Choosing a stamping die depends on the target design, stamping technique, and operation.

What Is Hot Metal Stamping Sheet Metal?

Hot stamping sheet metal is a hybrid stamping process that combines sheet metal forming, hot forging, and injection molding.

This technique is mainly carried out at temperatures higher than the metal recrystallization temperature to make the metal malleable into desired shapes.

Related Resources:

Metal Stamping Process

Stamping Process

Stamping Metal

Scroll to Top