Die Science: What makes a topnotch metal stamping plant?
Some stamping plants and die-building facilities are far more productive and efficient than others. Each shop typically has its own niche, as well as its own strengths and weaknesses. So what are the key decisions managers make that result in a successful stamping or die-building shop?
Staffing and Company Culture
Owners and managers of stamping and die-building facilities must have a comprehensive understanding of the intellect and leadership skills they will need to achieve success. Few people realize that designing, engineering, maintaining, and troubleshooting dies, presses, and manufacturing machinery require a team of extremely highly skilled employees. If you think your sheet metal stamping shop can be staffed by a few skilled individuals and many unskilled press operators, you are in for a long, hard, expensive struggle, probably followed by catastrophic failure.
You need to find people with the skills and education necessary to support your business. This will be more difficult than you think. Good tool- and diemakers come at a premium. Be prepared to invest in training your toolroom maintenance crew, press operators, machine/maintenance repairmen, and other technical trades in your shop.
But money alone will not make you successful. You also need a culture that supports internal motivation and leadership. All employees must feel good about their tasks and understand how important their jobs are. This approach, driven by servant leadership, will prevent turnover and help ensure everyone is working at peak performance.
Press operators and tooling setup personnel need adequate training. But sadly, it is not uncommon for company leaders to spend $700,000 on a press and tooling; add sophisticated light curtains, smart packs, die sensors, and system electronics; and then put that system in the hands of a worker who can’t even identify the basic components of the press and die.
Press operators can make or break your organization with one push of the palm buttons. They don’t need to be experts, but they must have a fundamental understanding of the machinery and how it operates. Teach them how the dies work and the precision level of the machinery. Make sure they clearly understand cost. They have to be able to communicate problems clearly to tooling technicians.
Educate your tool and die professionals. Learning from others on the job is valuable, but as technology changes, so do methods and processes. Some old rules of thumb passed down from years of experience no longer apply to today's high-tech, high-strength-material world.
Modern diemakers must be data-driven, not making decisions based on experience or trial and error. Successful technicians understand why tooling worked and know the physics behind what goes on in the tool. They always try to find the root cause for a dimensional or part failure and prevent it from happening instead of correcting it after it has already happened. This requires a comprehensive understanding of sheet metal forming, metal cutting, tool steel, and friction.
Tool maintenance personnel must understand grinding and metal finishing processes. They have to know the proper methods for tool steel replacement and die coating. They must understand how nitrogen gas springs and other critical die components operate and be able to maintain and troubleshoot those items. They need to understand spring deflection rates and know how to reset and refit precision components in the die. They also must be good at keeping records and documentation.
Tooling setup personnel must understand the importance of die location, cleanliness, clamping procedures, timing, pilot release, pitch and progression, feedline heights, shut height, tonnage readings, fundamental die protection, scrap removal, and lubricant application. They must be able to set up and calibrate sprayers, scrap chutes, scrap belts, and scrap ejection equipment and ensure that all are working properly. They also should have a good understanding of the die and how it operates.
In stamping, the press is just as important as the die. Presses must be well-maintained and checked periodically for parallelism and damage. The engineer must use the proper press for the application and avoid using under-tonnage presses, presses with extreme deflection, or sloppy presses for precision applications.
Of course, the tooling must be in top shape—properly engineered and well-maintained. It must be designed and engineered to feed, locate, and perform work as required. It must be made of materials that can withstand sometimes brutal punishment from high-strength materials. And it must be well-lubricated.
The press feeding equipment must be able to locate the coil properly with respect to the press and the die, especially if you’re running a coil-fed progressive or transfer tool. The equipment must be able to adequately flatten and straighten the material and feed the metal accurately into the die in precise increments.
The dies and press must be fitted with accurate die protection systems. Some shops keep a die sensor specialist on staff to ensure that all of the dies are properly engineered with the most effective die protection systems available and that each sensor system is operating correctly.
Sheet metal stamping is not simple. Successful stamping shops need not only high-quality tooling and machinery, but a great deal of human talent and skilled leadership—and, frankly, a lot of money. But if you invest wisely in your employees, shop culture, and equipment, you are on the right path for success.
STAMPING Journal is the only industrial publication dedicated solely to serving the needs of the metal stamping market. In 1987 the American Metal Stamping Association broadened its horizons and renamed itself and its publication, known then as Metal Stamping.