There are many manufacturing methods that are used by a wide range of industries worldwide to produce materials and prototypes. Of them all, metal stamping has proven to be one of the most reliable, effective, and cost-efficient methods. This popularity has–been influenced by the rampant increase in demand for metal products, parts, and components.
However, despite its widespread use, custom metal stamping can be a novel concept for many companies, especially those that have never tried the process. In this guide, we take an in-depth look at the custom metal stamping process. We tell you what the processes entail, the tools used, products produced, and how to apply them effectively to your manufacturing and prototyping processes.
What Is Metal Stamping?
Metal stamping refers to manufacturing metal parts, products, objects, components, and other substitutes of metal designs. With the increase in demand for these products, manufacturing industries are forced to come up with both reliable and quick manufacturing methods to keep up the supply.
The metal stamping process helps transform flat metal sheets into eye-catching and effective shapes. Examples of products produced this way include a set of L-shaped shelf mounts or a pre-packed wall-hanging kit that is usually sold in hardware chains such as The Home Depot.
In most cases, people don’t stop to wonder how such products are manufactured. Most don’t know that it involves custom precision metal stamping. In truth, the metal stamping process is key in the production of millions of products ranging from home products to heavy machinery and industrial items.
How Is Metal Stamping Done?
Since you now know what metal sampling means, the next step is to learn how the metal stamping process works. Metal stamping is also known as metal pressing because the process involves placing sheets of flat metal through a stamping press, either in coil or blank form.
In the stamping press, there is a tool and die surface that turns the metal sheets into visually appealing and usable shapes. There is also a press that is used to control a die and the piece part—which is created by pressing the sheets between the dies.
Before the resulting metallic item can be produced, professionals are required to sketch the tool with the help of CAD/CAM technology. During this process, it is really important for the drawn designs to be accurate and precise.
Additionally, you should know that a single-tool three-dimensional model can consist of hundreds of components. Hence, it is normal for the meta-design process to involve some complexities and time-consuming sub-processes.
What Kind of Parts Require Metal Stamping?
Generally, the metal stamping process is used to create large numbers of custom, complex components that require high tolerances. Below is a simple list representing samples of precision metal stamped parts arranged by the manufacturing industry:
Automotive: Transmission components, safety-related devices, engine components, busbars, seal belt items, brake parts, etc.
Insert Molding: Terminals, brackets, and lead frames.
Medical Equipment: Suture removal components, antennas, surgical staplers, battery housings, electro-surgery device components, and contacts.
Communications/Electronics: LED lighting components, contacts, fiber optic components, busbars, electronic connectors, light pipes, and high-speed cable ends.
Custom Metal Stamping
In simple terms, custom metal stamping refers to metal creating processes that require custom tooling and strategies to come up with parts as specified by the client. Several manufacturing industries adopt the custom stamping process to meet high-volume demand and supply needs. The process ensures all parts fit the customer’s needs and expectations.
Unlike the customary mass-produced stampings, custom metal stamping is specifically designed for a certain part and its functions. Custom metal stamping is preferred when accuracy and complex dimensions are required to create an original component.
During this process, a custom metal stamping tool is usually chosen to cut precisely and accurately from the designed shapes as the metal sheet goes through the stamping press.
Custom metal stampings can be done on large parts for automobiles and other minor components for medical equipment or electronics.
Types of Metal Stamping Techniques
There are only four key metal stamping techniques, which are clearly explained below.
1) Progressive Die Stamping
Progressive die stamping typically entails several stations, with each having a unique function. During this process, a metal sheet is passed through a metal press and then later enrolled into a die press. Each of the stations performs various functions that include cutting, pressing, or bending.
The progressive die stamping process is perfect for producing metal products with complex geometrical requirements and helping manufacturers achieve shorter run lengths, faster turnaround, increased repeatability, and reduced labor costs.
2) Deep Draw Stamping
The deep draw stamping process gets its name from the fact the drawn sheet depth exceeds its diameters. During this process, manufacturers are required to place a blank metal sheet into the die press via a punch and cut it into desired shapes.
Unlike the turning processes, the deep draw stamping process is considered more cost effective and efficient. Some components produced through this process include electronic relays, automotive parts, aircraft components, utensils, and cookware.
3) Short Run Stamping
Are you keen on keeping your upfront tooling expenses as low as possible? Then, the short-run stamping process is ideal for you. During this process, a blank metal sheet is created, and the manufacturer later leverages a combination of tooling parts and dies to bend, punch, or drill metal components.
The major downside of the short-run stamping process is that customizable forming operations and small run size can lead to an increased unit charge. This makes the process
less cost-efficient.
4) Fourslide Stamping
Just as the name suggests, the fourslide stamping process comprises four slides that usually allow manufacturers to use four different devices to complete bends simultaneously. With each shaft bending the sheet once it is placed into a four-slide, this process is arguably the most efficient and versatile stamping process. Provided the manufacturers get this process right, they can produce large volumes of complex parts-even those that require frequent design modifications.
Tools Used in Custom Metal Stamping
Despite the complex nature of the custom metal stamping processes, having the correct toolset can play a major role in you getting satisfactory results. The following are some quick guidelines that you should consider when looking for the right tool to use in custom metal stamping.
v Die Set Machine
Even the most intricate of dies requires repeatability. For instance, 5-axis CNC mills and wire electrical discharge machining (EDM) guarantee tight tolerances even when penetrating hard tool steel. When charged electrically, the wire EDM can shape metal components with a brass wire and cut through the most complicated angles, shapes, and contours.
v Stock Strip Layout
The created tool should follow the stock strip layout. You, as the designer, come up with the metal strip, determine its dimensions, feed direction, scrap minimization, tolerances, and other other technical considerations.
v Grinding Equipment
In most of the custom metal stamping processes, metal items are often exposed to heat treatment. Therefore, it is crucial to enhance the strength of the parts and boost their durability, which later improves the surface quality and precision of completed parts.
Custom Metal Stamping: Primary Processes
During custom metal stamping, several sheet metal forming processes are usually involved in producing the desired form of the metal component. The following are some of the major metal stamping techniques used to achieve the specified shape in the press.
1. Coining
Coining is a process that involves using excessive amounts of pressure to push the workpiece into a die. The die then later alters the metal into a certain shape and produces permanent forms in the workpiece. Coining helps smooth rough metal edge parts by exposing them to extreme amounts of force.
Coining helps harden the metal and eliminate the need for grinding, deburring, among other secondary processes, to save time and money.
2. Bending
Bending helps produce a formed feature through an angular displacement of the blank metal sheet workpiece. One edge of the workpiece is first clamped in a still position, while the other edge is clamped by a metal tool and bends over a form to have a certain shape or bend.
3. Blanking
The blanking process simply involves removing a metal piece from the primary metal sheet or strip by punching through the sheet/strip.
4. Drawing
Drawing involves controlling the flow of metal into a cavity through a pressure-loaded draw pad to minimize wrinkling as the sheet/strip flows over to form a punch. An intricate drawing can be used to manufacture large metal components, such as automotive parts.
5. Crush Forming
The crush forming process involves deforming the metal strip/ sheet using only a cavity and a punch. During this process, dies are usually not used to prevent the metal from buckling or wrinkling and control metal flow. Instead, they are used to create simple items, such as braces and brackets that are made from thick hard materials that are more resistant to wrinkling compared to thinner metal sheets.
6. Cutting
Cutting, one of the most common stamping processes, involves trimming the metal sheets/ strips by exposing them to a significantly high force in the stamping press. Some of the cutting techniques include notching, shearing, blanking, trimming, lancing, and piercing.
7. Embossing
Embossing is a cold-forming operation that involves the use of male and female embossing items to press a workpiece (metal pieces) between them with adequate force to create a three-dimensional feature.
8. Extruding
The extrusion process helps form the metal inside the diameter of a pierced hole, to be used for several applications, such as keeping fasteners in place during component assemblies.
Custom Metal Stamping: Secondary Processes
In order for a metal stamping product to meet all the vital requirements before being shipped to the client, it may require one or more secondary processes. Some metal stamping industries usually offer several processes in-house, including assembly, cleaning, and packaging. However, some secondary processes, such as electro-polishing, heat treating, plating, and e-coating, may require you to seek technical expertise and tools available only through specific suppliers.
The metal stamper’s engineering team provides guidance on the ideal processes for the stamping product and its uses. It can also oversee the secondary processes provided by your certified suppliers in order to finish, inspect, package, and transport the product to the manufacturer’s exact requirements.
Below are some of the secondary operations involved during the custom metal stamping process.
- Plating, over molding of medical-grade polymers and elastomers
- Electro polishing
- Painting, e-coating, powder, coating, among others, finishes
- Metal finishing
- Heat treating
- Deburring
- Laser welding and forming
- Passivation and cleaning
- Secondary tooling to cingulate and form at the client’s destination
- Spot welding and welding
Metal Stamping Materials by Industry
Due to their specific uses and the operating and environmental conditions that the components must endure, each firm prefers certain metals for their precision metal stampings. For instance, medical components require excess sanitation and safety standards. Automotive industry products must be able to withstand contact with several liquids and extreme cold and heat. Electronic devices, on the other hand, require a high electrical conductivity.
Each industry will have specific metals they prefer their materials to be made from to meet their needs.
The following are some examples grouped by industry.
Automotive Industry: Low-alloy steel, high strength steel. red metals such as brass, copper, and bronze
Medical Devices: Copper, niobium, aluminum, platinum, iridium, tantalum, stainless steel, custom shaped wire, and MP35N.
Electronic Devices: Custom-shaped wire, phosphor bronze, and several high-performance alloys, such as aluminum clad copper, and mill hard or post heat-treated beryllium copper.
Insert Molding: Aluminum clad copper, custom shaped wire, pre-plated ferrous and non-ferrous alloys, brass, and high-performance copper-based alloys.
Reducing Metal Stamping Costs
The following are three simple tips on how to cut down costs on the metal stamping process:
Check the volume of production and consider producing many workpiece parts at once.
Check the secondary operations by using a manufacturer that offers coating, treating, finishing, packaging, fabrication, and transporting.
Consider other suitable metal options that will perfectly suit your applications.
Design Engineering Assistance and Prototyping
Seeking professional advice from metal stamping engineers can help you come up with cost-effective designs that will help maximize your profits. With the use of 3D CAD technology, your metal stamping engineers will develop a suitable design, material, and print recommendations. They can also suggest modifications needed to lower the risk of failure and boost functionality.
Thanks to the advancements in custom stampings, it is now easy to test and analyze small key components of stampings before deciding to invest in high-volume production. Establishing a prototyping equipment process will help determine the potential downsides of the material prior to production and recommend other suitable tool functions to save on time and costs.
Prototype Design
Prototyping is normally used to test a design and confirm if the designed part will provide satisfactory results. Many modern firms prefer using prototype stampings to identify any potential complications with the manufacturing of the component and allow testing for other suitable and efficient production operations.
Types of Prototype Design
There are two main types of prototype design processes: progressive strip prototyping and single-part transfer prototyping. Let’s look at how they work.
Progressive Strip Prototyping
During the manufacturing process, the main purpose of the die is to guide the stock prototype workpiece. Meanwhile, automatic or manual feeders help move the material via each station, delivering a finished product at the final stage.
This implies that you can use the progressive strip prototyping design to alter small items to tight tolerances with fast turnarounds and minimal to no human error during the manufacturing process.
Single-Part Transfer Prototyping
The single-part transfer prototyping simply entails manually moving each prototype component from one station to another. This prototype design helps cut down on tooling expenses if the firm maintains a standard prototype design.
Benefits of Custom Metal Stamping Prototyping
Prototyping usually offers several benefits that often positively impact your final manufactured product. Some benefits of custom metal stamping prototyping include:
- Increased life expectancy of the final product
- Allows you to create components with intricate geometries
- Reduces the need for engineering modifications in the future
- Eliminates any unnecessary features early in the production process
- Exposes weaknesses prior to production
- Reduces mistakes that can lead to additional expenses
- Speeds up the manufacturing process- marketing your products faster
Conclusion
The custom metal stamping process can prove very effective in producing metal components and prototypes for your industry, especially if you understand how it works. To ensure success, it is important for you to be aware of the essential steps involved. You also need to familiarize yourself with the exact metal that can meet your needs.
When choosing a metal, review its temper, strength, grade, tolerance, thickness, weight, corrosion resistance, and hardness. As a manufacturer, you should also consider the physical characteristics of a metal and its suitability for your application.
Provided these steps are done correctly, the metal stamping process can prove quite simple.
