Punch Press or Laser? Choices for Cutting Metal

25Metal workers are tasked with manufacturing high quality, marketable products for their clients. Metal fabrication often starts with sheet metal materials that need to be cut and formed into usable metal parts that get moved along the supply chain to a point of final assembly. In metal working, there are different options for cutting, forming, coining, piercing, punching and bending the metal into the finished product your company needs. Several methods involve what is called a punch press, and another one entails the use of a high-powered industrial laser. Each uses a different process, achieves different end results and holds distinct advantages.

The Punch Press

Punch presses operate by first developing cutting dies, forming dies or progressive die sets. The die is the tool within the press used to cut and or form the metal, and a progressive die set is used in machines where coils of sheet metal material pass through several stations within a die set in one pass. Punching is a form of metal stamping, which is when a die is used to cut metal blanks with the aid of a die and a power press. The punch press is about speed and high-scale production, and is characterized by a number of features:

  • Force or power used to cut the metal
  • The tooling die and complexity of the die
  • Size of working area on the metal blank
  • Frame type

Progressive long run stamping, another fast and cost-effective method, uses a power punch press. The material (in coil form rather than pre-cut sheets) involves multiple cutting and forming stages through a single machine before the desired result is achieved. Precision metal stamping is a bit different; this process converts flat sheet metal into different commissioned shapes maintaining very tight tolerances.

Laser Cutting

A slightly more modern technique, industrial laser cutting services is about precision. A beam of heat energy sears into the metal and melts the excess away. This energy is often operated by CNC (computer numerical control). There are some particular projects for which laser cutting is best to use:

  • Tight intricate cuts
  • Multiple metal blanks all cut from the same plate of metal
  • Short run projects where tooling costs need to be avoided

There are many benefits to sheet metal laser cutting. For instance, laser cutting pre-painted metal without scarring the paint is possible with certain fiber lasers. There is also less chance of contaminating the material than with the cutting edge used in mechanical cutting.

Strengths and Weaknesses

Overall, both punch press cutting and laser cutting have certain advantages and disadvantages in the industry. Each are an asset to the task of metalworkers and their field, but in different ways. For more information, seek out a professional quote today.

Progressive Die Stamping Has Not Changed Much in 20 Years

You can see the impact of metal stamping using progressive dies in the building trades, consumer products, automobiles and the equipment we use to manufacture “things”. From everyday appliances in our homes to heavy machinery for large-scale industry, die stamped parts are in most every metal part in use today. While innovations continue to lead the metal forming industry forward, the foundation of progressive metal stamping remains the same, set in place in the early and mid-20th century. In the decades since, little has change because progressive die stamping methods of metal forming are basic; even cutting-edge manufacturers still follow the guidelines set in the 50s, and they still serve well today.

Early History of Progressive Die Stamping

The 1896 treatise titled The Press Working of Metals by Oberlin Smith, together with J.L. Lewis’s Dies and Die Making a year later, discussed “follow-on” tooling and the use of “successive gang cutting” techniques.These were the early beginnings of progressive dies. At its onset in the early 20th century, progressive dies saw fairly limited usage among companies in need of in-house manufacturing. Contract tool and die makers still relied on single-operation presses and workers loading and unloading materials by hand to transfer them between dies – a slow and often dangerous task, as hand-feeding strips and parts meant exposing unprotected hands to moving parts. The post-WWII metal manufacturing industry pushed production demands too increase outputs, and worker injuries on these single function hand transfer presses were becoming increasingly commonplace.

The Start of Modern Metal-Stamping Tradition

In 1953, design engineer Ed Stouten started a die design business called the Capitol Engineering Company in Grand Rapids, MI. He proposed an alternative: a multi-station progressive die where parts remained on the strip between operations and scrap material was reused. Sheet metal bending, cutting, punching and forming became a continuous process with little manual input between stages. Impressed, tool and die makers spread the word, and everyone wanted to try this new progressive die stamping process. Stouten developed an official manual and training course, Progressive Dies for Designers, Engineers and Manufacturers, and spent the next 50 years traveling the world along with leading die designer Arnold Miedema, giving seminars to share these new ideas.

The Legacy of Progressive Die Stamping

The fundamentals of progressive metal stamping remain the same not because of stagnation, but because of how significant the development was, and is, to the sheet metal bending industry. Stouten and Miedema’s seminars and designs remain vital for most tool and die makers in Pennsylvania and those outside our region. Manufacturers and customers everywhere owe it to Stouten’s work for the production of high-quality, reliable and safe die-stamped metal parts.

Cut Complex Geometries With Speed and Precision Using Fiber Laser Cutting

Precision is essential when cutting thin metal used in medical instruments, industrial equipment and parts for the electronics industry.The quality of the cut can have a significant impact on the effectiveness of the part, and negative consequences if tolerances are not adhered too. As a result, metal fabrication companies place quality and precision as a top priority, but also need to consider other factors to ensure their business thrives. A fiber laser cutting machine can produce high precision of metal cutting for some very complex shapes while contributing to business goals of cost reduction and improved lead times.

3 Dimensional Cutting

One of the most significant ways laser technology stands out among metal fabrication methods is its ability to work in three dimensions if necessary.A custom laser cutting machine using solid state processing can can cut intricate shapes in one pass with amazing precision, which is often an impossible feat for wire electric discharge machining(EMD), the next leading method. To create a three-dimensional shape using wire EMD requires additional equipment and software, which means higher costs and longer processing times. A CNC turning mill utilizes a 3-5-axis motion package, allowing it to cut in two or three dimensions with specialized cutting tools. A solid state fiber laser cutting service uses a beam of light, no investment in specialty cutting tools.

Speed

When it comes to speed, nothing compares to a fiber laser cutting service cranked up for speed.We have done over 7 different metal parts from one sheet of 108 inch metal. The computer onboard arranges the shapes to make the most economical use of the metal sheet, minimizing waste.  Other fabrication methods require several passes to achieve the same level of precision and take much longer to complete the 7 different parts.

Laser technology also includes the option to utilize fusion cutting, which introduces gas to the cutting zone during the process. When oxygen is added, the speed can increase up to 50% without detrimental effects on the quality.

Accuracy and Quality

Metal fabrication with lasers can provide the cleanest edges of any method. The intense focus of the laser also allows for incredible precision. Laser technology can create products that have:

  • Exit sides with minimal dross/burr
  • ±0.001 in. dimensional accuracy
  • Less than 0.002 in. cut width
  • Less than 0.3 µm “as cut” roughness

Fusion cutting can also be used to increase the quality by using nitrogen instead of oxygen. Although this is a slower process, the mobility and power of a laser ensures that fusion cutting with nitrogen is still a quicker process than a turret punch press for example.

A laser cutting service proficient operating their equipment can produce high quality metal blanks while ensuring a quick turnaround. Metal fabrication with lasers is transforming the way metal fabrication companies in Philadelphia and meeting the demands of their clients. Custom laser cutting of metal is slowly replacing the way complex metal parts are made today. The additional option of fusion cutting with oxygen, nitrogen or argon as an assist gas can speed up production times but should be allowed specialized jobs due to controlling gas emissions.

Cutting Complex Metal Blanks Just Got Easier, Faster and More Affordable

There are thousands of products that are manufactured using metal parts cut the old fashion way. This article is focused on laser cutting technologies that are faster and a more affordable way of cutting metal parts. Almost all kinds of metals such as the mild steel, aluminum, and nickle alloys can be cut using the advanced laser technologies that are available.

Laser cutting achieves high precision cuts as well as improved production speed compared to punch presses and shears. Lasers are highly programmable and don’t require any tooling.

The laser cutting helps get more complex parts done with less waste.There are two primary types of laser technologies that are available for cutting complex parts, One is CO2 lasers and the other is solid state fiber laser cutting machines. One of the major benefits of fiber lasers is the minimized energy consumption compared to CO2 laser machines currently on the market.

Fiber Lasers

Fiber lasers tend to do a better job with thinner metal sheets. TruDisk solid-state lasers enable you to work quickly, particularly in thin sheet metal. This is possible because they emit abeam with a wavelength of approximately 1.03 µm, which is absorbed significantly more intensely than the wavelength of CO2 lasers: these lasers transfer more energy to the sheet metal, enabling cutting to be carried out more quickly.

CO2 Lasers

CO2 lasers are particularly effective for any applications that require especially smooth and high-quality cut edges. They are the right choice for cutting edges that will be visible and where smooth edges matter for the further processing of your part. CO2 lasers are an older type of laser technology, which means that in general, the price to acquire them has come down over time.  Yet, it’s a technology that has continued to evolve beautifully, even as prices fall. CO2 lasers, while not as fast as their fiber cousins, are extremely flexible and adaptable for use on the most common types of materials, such as aluminum and steel, and on a range of material thicknesses.

When investigating a laser cutting service for your next fabricated metal part, it would be wise to quote out a few companies that do metal fabrication with lasers and ask them about the quality of the cutting surface for the metal parts you are making. If you are just doing a laser cut for metal blanks that don’t require any forming, you may not be concerned with the type of machine. But if you are doing some custom laser cutting of more complex parts that need additional forming, then we recommend that a fiber laser cutting service get involved in the project. Not every metal fabrication shop in Philadelphia is created equal.

Challenges and Considerations of AHSS Metal Stamping

Designing and producing lighter-weight vehicles is a primary goal of some automobile manufacturers. Less weight allows for improved performance, safety and fuel economy while also reducing material costs. Advanced high-strength steel (AHSS) alloys represent a strong candidate for use in structural components of automobiles. They also present new difficulties in alloy composition; OEMs should pay attention to ongoing research in their formation, properties and effective stamping of these metal parts.

Observed Advantages of AHSS

Conventional mild steels have low carbon content and minimal blending elements which result in simple microstructures. AHSS alloys use carefully controlled additions of alloying elements to produce complex multi-phase structures with unique mechanical properties. There are a variety of AHS steel compositions and their properties provides considerable versatility. Dual-phase (DP) steels and transformation-induced plasticity (TRIP) for example, already see considerable use in vehicles. DP steels are highly resistant to fractures and necking. TRIP steels demonstrate a capacity for high energy absorption under sudden strain, excellent for the “crumple zones” of vehicles.

Formability Concerns of AHSS

Formability – the ability of a piece of metal to undergo plastic deformation without sustaining damage – is a critical trait for automotive alloys to ensure that parts do not fracture within metal forming presses. AHSS alloys, however, exhibit issues with formability as it relates to springback during some more complex precision metal stamping processes. Assessing the related mechanical properties of AHSS, in turn, is difficult with usual testing because the multi-phase structure leads to non-constant strain hardening. The viscous pressure bulge (VPB) test has shown promise, though, in constructing flow stress curves for AHSS samples.

Effective Modeling of Fracture States

The forming limit curve (FLC) is a standard in predicting the forming behavior of sheet metal to illustrate stress states that result in fracture. Traditionally, this involves a series of tests at varying ratios of shear and strain to determine when fracture occurs, but the variability of AHSS responses to strain make this especially costly in time and materials. The Center for Precision Forming at Ohio State University, however, has demonstrated a “three-point technique” for approximating the FLC with just three tests: pure shear, pure strain and biaxial tension. This can provide a more time- and cost-effective method for OEMs and their progressive metal stamping companies they work with.

The advances made in newer metal forming presses allow sheet metal stampers in PA to make fine adjustments to speed and force when forming critical shapes. There is great promise for precision metal stamping in the automobile industry. Further research in controlling the properties and performing effective testing and working will help manufacturers realize goals of more efficient automotive design.

Deciding Between Die Stamping and Laser Cutting? Consider This

As a metal fabrication buyer, you may have questions about the differences between die stamping and laser cutting from a quality and economy’s standpoint. There are advantages to each process and knowing what those are can ensure that you choose the right option. We’ll go over how the processes work and why one or the other might be better for your specific purposes.

Metal Stamping Process

Die stamping is a process where a metal die is made according to the final drawing of your part and is installed into a power press that is used to fabricate metal. The die is pressed into the metal to pinch it into the shape that is needed. This type of process requires the right metal substrate and the correct force to stamp, mold and shape that metal. Progressive dies can perform multiple tasks in one pass through the equipment.

Laser Cutting Process

Sheet metal laser cutting involves the use of a CO2 laser machine or a fiber laser cutting service which cuts the metal into a specific shape that remains flat. There is no die required because the drawing is input into the computer of the laser machine. However, this also means that the metal part can only be made into a flat shape. Die stamping allows the shape to be molded and turned into a specific piece that you need.So there will be additional passes through a press brake that may be required to shape the metal part. If your part is nothing more than a flat shape, this may be a wonderful option.

Differences Between Die Stamping and Laser Cutting Service

When you are using the stamping method, one of the disadvantages is the need for a physical die tool to me made by a craftsman. The creation of the die can be time-consuming, requires hardened tool material and can be costly to produce depending upon its complexity.As for sheet metal laser cutting, a technician programs the computer based upon the drawing provided so there are some labor costs and required skills involved but the time and material costs are significantly reduced.

Not all fabricators have opted for laser cutting equipment. The machines are a big investment and the payoff may be years.If your part requires metal forming, bending and other processes, a progressive die stamping company might be better equipped to handle your metal part. If your part requires only blanking, cutting and coining, perhaps a company that has a newer fiber laser cutting machine is a good partner.

The Right Choice for You

The metal part drawing and the sheet metal thickness and quality will be required for you to make the right decision. Not all steel fabrication companies are considered equal and encourage you to do your due diligence. Get a quote, a few testimonials and have the conversations with your partner. Ask if they are an ISO Certified metal stamping company and ask to see their certificate.

Progressive Metal Stamping Dies Get Complex

Mass production of metal parts using progressive die stamping helps manufacturers complete multiple forming operations in a single pass through the press. The stamping dies that are crafted for the bending, piercing and forming of these parts can get very intricate. In order to create the least amount of waste for the strongest result, sheet metal forming companies often have to make several intermediary steps or stages in the metal forming process that minimizes stress on the parts they are making.

Orientation and Rotation

Long run stamping is done on a sheet of metal that is fed through the machine via a roll or coil of metal. There is a need to synchronize the metal pull length with the die stages. Running perpendicular to the metals grain direction is usually the best option, but some amount of rotation may be performed to reduce material waste. Performing a variety of tests and creating multiple samples are useful to determining where the tradeoff in strength and waste lies. No matter how much you save on material costs, you lose out in the long run if your parts durability is minimized.

Keeping It All Together

As parts pass through a progressive die, some scrap between each stage helps carry the entire strip through. This method of “carrying the part,” where some scrap is left between each piece, is the most common and produces minimal scrap. Each of the metal stamping companies in Philadelphia we have interviewed for this post manufacturer their dies differently in an effort to get the end result cost effectively.

A different carrying method is to is to use a guide edge to pull the strip through the press and stamp the part die on the other side of the metal strip. This method can create problems in lift since the strip can only be held on one side and a balanced strip progresses more easily than an unbalanced one. This method was far less common with the die stamping companies we interviewed.

Ladder style is the third type of carrying method and it consists of adding material on both sides. This is a balanced version of the second method but can produce much more waste. As with any long run stamping project, a balance must be struck between ease of manufacturing, material strength and material waste.

Exiting the Die

During the design process, it’s important not to overlook the act of exiting the die. Some exit strategies involve the part falling naturally off the metal strip, but the balance must be right for this to happen. Any flanges or tabs added can affect the need for any finishing tasks like deburring. It is best to have your tool die makers in house when working with long run stamping dies because the wear and tear on the dies is greater and therefore maintenance is required to extend the life of the dies. Most sheet metal forming companies have a variety of tools and techniques to make the parts a client needs.