Sheet Metal Stamping 101, Part I

Editor's Note: This series presents an overview of metal stamping. Part I focuses on the various careers in the metal stamping industry. Part II discusses stamping materials and equipment; Part III focuses on dies and cutting and Part IV offers more detail about cutting processes. The final installment, Part V, investigates forming methods.

To remain employed in today's economy, you must be diversified with respect to your skills. With cutbacks, companies now have fewer resources to get the work done. Employees often wear many hats. One minute you're a tool and die maintenance technician, the next you're in quality control, and then you're in the quoting department. You get the idea.

Because my "Die Basics 101" series is so popular, I decided to launch a new series that expands upon the fundamentals of stamping dies and processes and provides a more in-depth view of the overall metal stamping process.

You probably are reading this article because you either work with stamping dies, or would like to in the future. This introductory article is intended for those individuals with very little or no sheet metal stamping experience. As a process engineer, die designer, diemaker, setter, or die maintenance technician, you will find it helpful to know which piece of the larger puzzle you are.

How Stamping Affects Our Lives

There is no doubt that stamping has dramatically changed our lives. Common household items such as washers and dryers are made using a sheet metal stamping process. Items that we often take for granted, such as the flatware we use for eating, the pots and pans we cook with, and the car we drive, are manufactured partially by sheet metal stamping. Beverage cans, cigarette lighters, gun shells, even certain types of solid gold jewelry are manufactured using this process. The computer on which you are reading this article contains stamped parts.

How Stamping Is Viewed

It's very interesting to me how the perception of sheet metal stamping and diemakers varies from person to person. Some people think of stamping as a typically dirty "factory-type job," while others think diemakers are highly skilled individuals who are good with their hands. The truth is, die designing and -making, troubleshooting, and maintenance are professional career paths. Good die designers and -makers are better with their brains than with their hands. Many of the hands-on skills needed in the past have been replaced with new processes, such as wire burning and CNC.

In any case, as stampers, we must be masters of the trade and accept nothing less than perfection. Keep in mind that perfection in the tool and die industry means that everything important must fit and function properly. Fit and function is the key. Some die components must be manufactured with extreme dimensional accuracy, while others do not require as much accuracy. The key is to take the time to make precision components dimensionally correct, and don't waste time on less critical items.

Beauty Goes Only So Far

As a consultant, I find it somewhat frustrating to see a die that looks as good as jewelry when only parts of it need to be so. Although the toolmaker may be proud of the appearance of the tool, spending time polishing things in the die that don't need to be polished is wasteful. Companies typically don't purchase dies based on their physical appearance but rather their performance. Take pride in the performance of the tool, not its appearance.

Science—Not Art

Pursuing a career as a tool- and diemaker or designer can prove to be a great choice for many individuals. First let's dismiss some of the vicious rumors about the die building and stamping trade. Despite what some toolmakers may tell you, the occupation is not an art form. It is a science and a professional career path. Good diemakers and designers don't make decisions based on an inspiration they had earlier that day. Their intent is not to build something that is intended to "inspire" emotion.

Don't confuse creativity with art. Toolmakers and designers must be very creative in their thought process. Unlike an artist, who intends to inspire emotion, a die designer must create something that functions correctly.

To be a good diemaker or designer, every decision that you make with respect to the die must be based on a good understanding of physics. It's very simple: If you throw an apple in the air, it will fall. It doesn't matter how artistic you are.

A career as a tool- and diemaker is not only very challenging, but also requires a great deal of education. Some of that education is in an academic form, while the bulk of your learning will come with actual shop floor experience. Although you may not end up with a degree from the University of X, rest assured, this is a professional career path. I work with many academic professionals, some with Ph.D.s, who consult with me on projects. It is only through the combined efforts of academic and real-world experience that we can realize success.

As a diemaker or designer, you could be responsible for making decisions that end up costing thousands and sometimes millions of dollars. Judgments should not be taken lightly; a poor decision can devastate an organization. A baker can eat his mistakes, but a bad die can't even be used as a boat anchor. More the reason to strive for perfection.

Why Sheet Metal Stamping?

The System. You've heard the phrase "necessity is the mother of invention," which can be summarized in one word: need. Large companies, such as automotive, aircraft, or appliance manufacturers, often drive the need for sheet metal tooling. These companies are called original equipment manufacturers (OEMs).

If an OEM sees a need for a part or a new product line, it will go about determining the best way to produce it. This is where a great deal of knowledge about the many different processes is important. For example, if a large-volume part can be stamped as opposed to casting, the part can be produced at a significantly lower cost.

Some OEMs have the capacity to build the tooling and run the dies themselves; however, they often outsource their part production needs. This means they may hire a company to provide the parts to fill their need. These outside companies that work directly with the OEMs are called Tier 1 suppliers.

In the sheet metal stamping business, a Tier 1 supplier generally owns several stamping presses and hopes to get a contract to supply parts to an OEM. But the OEM doesn't just give supplier contracts away. The Tier 1 supplier has to bid on the contract. Once the company has landed a contract to supply parts, it must build the stamping die that runs in its presses to create the parts. The company may have a division that builds dies, but many must find a tooling source to supply the die, which in turn must bid on the contract to build it.

What Is a Sheet Metal Stamping Operation? A sheet metal stamping operation is one in which sheet metal is cut and formed into a desired shape or profile. Although a sheet metal stamping process may utilize numerous types of special machines, three basic items are essential: the sheet metal from which the part is to be made; the stamping press; and the stamping die.

With the exception of a specialized sheet metal stamping process commonly referred to as hot stamping, most sheet metal stamping operations involve cold forming. This essentially means that no heat is intentionally introduced into the die or the sheet material. However, keep in mind that although stamping is a cold-forming process, heat is generated. Cutting or forming sheet metal creates friction between the die and the metal—much like the friction and heat that occur when you rub your hands together.

Because heat is generated from friction during the cutting and forming process, stamped parts often are very hot when they exit the dies.

What Are Some of the Different Professions Associated With Sheet Metal Stamping? You can pursue many stamping-related careers, such as process engineer, die designer, machinist, diemaker, or die maintenance technician.

A process engineer is responsible for determining the steps needed to turn a flat sheet of metal into a finished part—a critical task and an important position. A single process error can quickly spell failure.

Die designers are responsible for designing the tools to effectively execute the process that has been established. Many individuals serve as both process engineers and die designers. Effective die designers have a good understanding of mechanical motion, as well as material strengths and tool steel types. They are skilled at operating CAD or computer-aided software.

Machinists are responsible for cutting die components from specified materials to their proper dimensions.

Diemakers assemble and construct the tool. They also must test the die to make sure it functions properly and consistently produces an acceptable piece part.

Production die maintenance technicians maintain, repair, and troubleshoot stamping dies.

Watch for the next installment of the "Sheet Metal Stamping 101" series. Please feel free to contact the editor of this publication to suggest future topics.