Reducing Costs in the Metal Stamping Process
According to LinkedIn:
Metal stamping uses pressure and precisely designed dies to stamp sheet metal into simple or complex metal forms. This manufacturing process can create a wide variety of components and products. It encompasses a range of specific techniques, including the following:
- Bending. Bending processes use a die with shallow-angled edges to shape an already cut piece of sheet metal.
- Blanking. In this shearing process, a die and a pressing machine cut shapes out of sheet metal. These cut-out shapes are called blanks and kept for use, while the remaining lattice of metal is scrap.
- Piercing. Much like with blanking, a die and a press machine shear metal shapes out of a sheet. With piercing, the metal left behind is the desired result and the cut-out portions are scrapped.
- Punching. This process uses a punch to force a hole into the metal sheet. The sheet rests on a die that supports the metal so the edges surrounding the punched-out hole don’t break.
Metal stamping is a cost-effective manufacturing technique if you choose the correct equipment and methodology throughout the design and manufacturing stages. In this eBook, we’ll discuss the equipment manufacturers use to stamp metal, the advantages of the process, and how to choose the most cost-effective methods for your products.
Equipment
Using the right metal stamping equipment can drastically impact the total cost and time commitment of manufacturing. Four-slide stamping machines and progressive die stamping set-ups offer ideal solutions for high-volume production.
Four-slide Machines
Four-slide machines create curves and bends in the metal. The equipment is capable of creating multiple bends, each with a radius exceeding 90° but without sharp bends or folds. These machines are typically used to create intricate shapes from metal coils.
Four-slide machines handle nearly simultaneous operations. They have four shafts across a series of bevel gears that quickly perform subsequent processes. The shafts have slides that each handle a striking tool, and the four slide tools strike the coil from orthogonal horizontal directions to create the rounded form. This series of motion repeats based on the input design to create precise, repetitive forms.
The manufacturing process can be customized to require more or less handling, machines, and secondary processing steps based on the specific end product. Four-slide machine stamping is generally more cost-effective than other stamping methods.
Keats Manufacturing has one of the world’s largest four-slide machine fleets. We’re the only American metal stamper that uses Wünsch Multi-slide forming machines.
Traditional Punch Press/Progressive Die Stamping Machines
Progressive die stamping, on the other hand, is a manufacturing process that carries a workpiece through several different stations to create a final product. Each workstation handles a specific series of functions on the workpiece while it’s still attached to its stock strip. At the final station, one of the last operations is to cut the piece away from the strip.
The stations use progressive stamping dies to process the raw material based on strict design specifications. Automation is frequently implemented to help make the process more cost-effective and ensure high repeatability rates. The dies can handle both primary manufacturing operations and some secondary operations. This progressive style of manufacturing reduces the total number of separate steps to take a workpiece from sheet metal to the finished piece.
Optimizing Material Use
One of the most efficient ways to reduce the total cost of a production run is by reducing material waste.
Material Content Reduction
Modifying product designs to remove excess material can dramatically reduce the material costs of a given project. It is often possible to adjust total material usage by reorienting how a series of parts are laid out on the raw sheet metal. Common methods include:
- Shifting workpieces closer together
- Laying out a large series of parts like puzzle pieces instead of isolated strips
- Combining related parts with different dimensions onto the same sheet layout
Even if these adjustments only generate space for one extra piece for every ten, that’s a 10% increase in efficiency.
Choosing the right metal stamping method also reduces material waste. Four-slide machines use material more efficiently than direct stamping methods. This is because stamping methods like piercing and blanking rely on the existence of excess material that the die can punch through. Four-slide processes can work with material that’s already at the desired width of the final part.
Strip Layout
Strip layout processes take significant planning. Die designers carefully determine the nature and order of each stamping operation, the materials needed, and the processing that occurs at each progressive workstation. This meticulous planning lets your company select the right amount of material, know the manufacturing costs upfront, and make more precise decisions without having to allow for a large potential margin of error.
Generally, strip layouts have at least a 75% utilization rate for the work material. The position and ordering processes are tested to ensure the most efficient order of operations and machining processes.
Designing for Manufacturability
Designing for manufacturability can create a more cost-effective manufacturing process. This requires taking manufacturing requirements and limitations into consideration while creating the product design. Experienced tooling professionals can predict the time it would take to manufacture the units and determine if the project can be achieved by a set deadline.
Even more importantly, experienced metal stamping professionals can use their expertise and advanced software to recommend and test design changes that will make the timeline more feasible. It’s vital to analyze the designs as soon as possible to catch potential flaws long before the manufacturing process starts. Once production begins, catching elements that can’t be completed to spec would be expensive for your company since tooling would have to be modified or refabricated to implement any new design changes.
Keats Manufacturing offers Design for Manufacturability (DFM) services that helps catch design and engineering flaws before it’s too late. DFM services should start as soon as there is a print of the component design. At that point, engineers can weigh in on the following factors:
- If the component’s configuration is feasible
- The expected difficulty and timeline of producing each unit
- The difficulty of maintaining quality standards during production
- What tolerances the component design can have
- The cost of production as-is
- Potential improvements or modifications to reduce cost, time, difficulties, and quality issues
Run Speed & Cycle Time
Time-cost should figure heavily into the cost of production. Units that take too long to produce will generate direct service and labor costs. There are also indirect costs related to production delays, slow shipments, and inconsistent availability.
Four-slide machining processes are fast—they can produce between 30 and 250 parts per minute, depending on their complexity. Four-slide machine processes also have fewer design and post-production steps, lessening the chance of delays.
Progressive die stamping is also fast because it has a continuous feeding process. This means there will be fewer material changes and delays. High-volume orders will be completed faster through progressive processes compared to traditional die-stamping and have a very low per-unit cycle time. Instead of having to pause for multiple setups and process changes, progressive stamping just moves the workpiece from station to station like an assembly line.
Place Your Order with Keats Manufacturing Today
Keats Manufacturing specializes in fast, high-quality metal stamping. We provide custom metalworking services and our team delivers professional, fast product runs. We build all of our dies and tools in-house with our EDM and CNC machines, so the quality of all components is in our control. Our precision equipment ensures we can maintain tolerances of up to 0.0005” during every step of the production process.
Contact our team to learn more about our design support and manufacturing services or request a quote today to get your order started.