The Metal Stamping Process: An Introduction

Posted by Heiwhite on September 3rd, 2024

Steel manufacturers, as well as leading industrial and consumer product manufacturers, rely on National Material Company as a global leader in steel processing and supply chain management. As part of its wide range of steel processing capabilities, NMC offers metal stamping services. Read on to learn more about metal stamping:

Process of metal stamping

A metal stamping process transforms flat metal sheets or coils into intricate and precisely shaped parts by using force, pressure, and specialized tooling. Components with diverse forms — like bends, curves, cutouts, and embossing — can be manufactured with force, pressure, and special tooling. While maintaining consistency in quality, dimensional accuracy, and repeatability, this process offers low costs and higher lead times for both short and long production runs.

The Process

An integral part of metal stamping is the stamp press, which applies the necessary pressure and force to mold metal sheets and coils into the desired shape. Dies are specialized tooling that performs multiple stamping operations on metal with this powerful machine. It is through the careful control of the movement of the press and the interaction between the dies and the metal in the production line that the stamping process produces remarkable changes in the shape and structure of the material.

Preparation of design and tooling

The stamping process begins with meticulous design and engineering, which carefully plans the desired part geometry. Stampers consider a variety of factors such as the material properties, die design, and tooling requirements. In order to ensure accuracy of the design, it is plotted using computer-aided design (CAD) software or computer-aided manufacturing (CAM) software. When the tool design is complete, a variety of machining tools and technology are used to fabricate the specialized tooling (for example, blanking dies, forming dies, and piercing dies). During stamping, the tool and die design must ensure adequate material flow, clearance for the metal sheet, and support for the part.

Preparation of materials

A specialist chooses a metal sheet or coil based on the part's specifications, including mechanical properties such as strength and ductility. Other factors include corrosion resistance, conductivity, and cost. Stamping and the desired part's functionality should be compatible with the material selected.

The feeding process

The selected materials undergo preparation processes like cutting, slitting, and leveling to obtain the proper dimensions and flatness necessary for stamping. An automated feeding mechanism ensures precise positioning of the prepared metal sheets and coils in the stamping press for an accurate stamp.

Operations related to stamping

As the stamp press initiates its action, the dies close together, causing the metal to be subjected to high force and pressure. In addition to deforming the material according to its contours, stamping may involve a variety of metal-forming processes. Depending on the design of the part, these experts may perform blanking (cutting out the desired shape), bending (creating angles or curves), coining (adding fine details), and punching (making holes).

To ensure that the parts meet the specified tolerances and quality standards, operators implement quality control measures throughout the stamping process.

Post-processing and finishing

To enhance the appearance, durability, and functionality of stamped parts, these professionals may apply additional post-processing steps, such as deburring (removing sharp edges), cleaning, surface treatment, and coating.

By following this systematic approach, the stamping process transforms raw metal sheets or coils into precisely shaped components that serve diverse industries and applications. This combination of precision engineering, material science, and advanced manufacturing techniques continues to revolutionize the way complex metal parts are manufactured.

There are several types of metal stamping, each with its own specific techniques and processes. Here are a few common types:

Stamping progressive

It involves the use of a series of dies that are arranged in a progressive order during high-volume production. As metal sheets or coils are fed through the dies, each station performs a specific operation, such as cutting, bending, or forming. It allows for the creation of complex parts with multiple features at the same time.

Stamping by transfer

Similar to progressive stamping, but instead of the metal sheet moving continuously through the dies, mechanical systems transfer the sheet from one station to another. This method is often used for parts that require additional operations or precise positioning, especially those that are larger and more complex.

Stamping on four slides

This technique, also known as multi-slide stamping, uses a four-slide machine to sculpt intricate shapes or simultaneously bend and form multiple parts. For small, complex parts with multiple bends or curves, multi-slide stamping is commonly used.

Drawing in depth

With this stamping process, cylindrical or box-shaped parts are created with significant depth. A specialist places a blank over a die and forces it into the die cavity using a punch. As the metal undergoes plastic deformation, it takes the shape of the die cavity, creating deep-drawn components.

Blanking of fine quality

A precision stamping process used to produce high-quality, burr-free parts. It uses a specialized fine blanking die that incorporates three distinct cutting edges. Fine blanking is commonly used when components need exceptional flatness, dimensions, and edge quality.

Among the primary types of stamping processes, each has its own advantages and applications, and manufacturers choose the most appropriate method depending on factors such as the complexity of the part, the production volume, and the quality that is desired.