Understanding Metal Stamping Metal stamping
is a cold-forming process that makes use of dies and stamping presses to transform sheet metal into different shapes. Pieces of flat sheet metal, typically referred to as blanks, is fed into a sheet metal stamping press that uses a tool and die surface to form the metal into a new shape. Production facilities and metal fabricators offering stamping services will place the material to be stamped between die sections, where the use of pressure will shape and shear the material into the desired final shape for the product or component.
This article describes the metal stamping process and steps, presents the types of stamping presses typically employed, looks at the advantages of stamping compared to other fabrication processes, and explains the different types of stamping operations and their applications.
Basic Concepts of Metal Stamping
Metal stamping, also referred to as pressing, is a low-cost high-speed manufacturing process that can produce a high volume of identical metal components. Stamping operations are suitable for both short or long production runs, and be conducted with other metal forming operations, and may consist of one or more of a series of more specific processes or techniques, such as:
Punching and blanking refer to the use of a die to cut the material into specific forms. In punching operations, a scrap piece of material is removed as the punch enters the die, effectively leaving a hole in the workpiece. Blanking, on the other hand, removes a workpiece from the primary material, making that removed component the desired workpiece or blank.
Embossing is a process for creating either a raised or recessed design in sheet metal, by pressing the raw blank against a die that contains the desired shape, or by passing the material blank through a roller die.
Coining is a bending technique wherein the workpiece is stamped while placed between a die and the punch or press. This action causes the punch tip to penetrate the metal and results in accurate, repeatable bends. The deep penetration also relieves internal stresses in the metal workpiece, resulting in no spring back effects.
Bending refers to the general technique of forming metal into desired shapes such as L, U, or V-shaped profiles. The bending process for metal results in a plastic deformation which stresses above the yield point but below the tensile strength. Bending typically occurs around a single axis.
Flanging is a process of introducing a flare or flange onto a metal workpiece through the use of dies, presses, or specialized flanging machinery.
Metal stamping machines may do more than just stamping; they can cast, punch, cut and shape metal sheets. Machines can be programmed or computer numerically controlled (CNC) to offer high precision and repeatability for each stamped piece. Electrical discharge machining (EDM) and computer-aided design (CAD) programs ensure accuracy. Various tooling machines for the dies used in the stampings are available. Progressive, forming, compound, and carbide tooling perform specific stamping needs. Progressive dies can be used to create multiple pieces on a single piece simultaneously.
The Basics of Metal Stamping Metal stamping
is a manufacturing process used to convert flat metal sheets into specific shapes. It is a complex process that can include a number of metal forming techniques — blanking, punching, bending and piercing, to name a few.
There are thousands of companies across the U.S. that offer metal stamping services to deliver components for industries in automotive, aerospace, medical, and other markets.As global markets evolve, there is an escalated need for quickly-produced large quantities of complex parts.
Stamping — also called pressing — involves placing flat sheet metal, in either coil or blank form, into a stamping press. In the press, a tool and die surface form the metal into the desired shape. Punching, blanking, bending, coining, embossing, and flanging are all stamping techniques used to shape the metal.
Before the material can be formed, stamping professionals must design the tooling via CAD/CAM engineering technology. These designs must be as precise as possible to ensure each punch and bend maintains proper clearance and, therefore, optimal part quality. A single tool 3D model can contain hundreds of parts, so the design process is often quite complex and time-consuming.
Once the tool’s design is established, a manufacturer can use a variety of machining, grinding, wire EDM and other manufacturing services to complete its production.
Types of Metal Stamping
There are three major types of metal stamping techniques: progressive, fourslide and deep draw.
Progressive Die Stamping
Progressive die stamping features a number of stations, each with a unique function.
First, strip metal is feds through a progressive stamping press. The strip unrolls steadily from a coil and into the die press, where each station in the tool then performs a different cut, punch, or bend. The actions of each successive station add onto the work of the previous stations, resulting in a completed part.
might have to repeatedly change the tool on a single press or occupy a number of presses, each performing one action required for a completed part. Even using multiple presses, secondary machining services were often required to truly complete a part.
Traditional machine vision solutions are designed to inspect only one item at a specific point on the production line. This makes them unpractical for a sector such as plastic injection moulding
, where the same production line can potentially make various products that come in varying shapes and forms.
However, Inspekto TYPES?, one of the many apps that can be installed on the S70, allows plastics manufacturers to overcome this issue. While traditional machine vision solutions can only monitor one product at any given location on the production line, an S70 system installed with TYPES? is able to inspect any number of products — even tens or hundreds of different products — at that same location on the line.
Emerging from the traditional constraints of one-product-per-solution, AMV allows manufacturers to inspect a variety of items with one single system, something that was unthinkable until recently.
Self-adjusting camera parameters
Another typical problem in this sector is achieving the correct lighting of the parts to be inspected. Typically, injection moulds have smooth, highly reflective surfaces that resemble mirrors. Additionally, moulds can be the same colour of the plastic polymer, or can appear that way because of a lack of contrast due to insufficient illumination of the inside of the mould.
Finally, moulding machines are built to be as compact as possible, so that they will open just enough to eject the part, but not enough to guarantee adequate illumination for visual QA.
All these challenges make inspection hard for traditional QA solutions, but not for AMV systems, which are designed to self-adjust their camera parameters to obtain perfect lighting, focus and contrast. In this way, the plastic parts can be illuminated in a way that clearly differentiates one from the other, allowing the system to perform effective visual QA in total autonomy.
An assembly line is a manufacturing process in which interchangeable parts are added to a product in a sequential manner to create an end product. In most cases, a manufacturing product assembly
line is a semi-automated system through which a product moves. At each station along the line some part of the production process takes place. The workers and machinery used to produce the item are stationary along the line and the product moves through the cycle, from start to finish.
Assembly line methods were originally introduced to increase factory productivity and efficiency. Advances in assembly line methods are made regularly as new and more efficient ways of achieving the goal of increased throughput (the number of products produced in a given period of time) are found. While assembly line methods apply primarily to manufacturing processes, business experts have also been known to apply these principles to other areas of business, from product development to management.
The introduction of the assembly line to American manufacturing floors in the early part of the twentieth century fundamentally transformed the character of production facilities and businesses throughout the nation. Thanks to the assembly line, production periods shortened, equipment costs accelerated, and labor and management alike endeavored to keep up with the changes. Today, using modern assembly line methods, manufacturing has become a highly refined process in which value is added to parts along the line. Increasingly, assembly line manufacturing is characterized by "concurrent processes"—multiple parallel activities that feed into a final assembly stage. These processes require sophisticated communications systems, material flow plans, and production schedules. The fact that the assembly line system is a single, large system means that failures at one point in the "line" cause slowdowns and repercussions from that point forward. Keeping the entire system running smoothly requires a great deal of coordination between the parts of the system.