Avoiding the Seven Deadly Sins of Stamping: Part 1January 19, 2024
Ignoring Material Type, Grade, Thickness
I would like to thank the leaders and staff of the Precision Metalforming Association as well as the editors and staff of MetalForming magazine for inviting me to author the Science of Forming column and to honor its previous author of several years, Dr. Stuart Keeler. I was blessed to have the opportunity not only to learn from Dr. Keeler but to perform a few consulting jobs with him. His research, including the development of forming limit curves, changed the way we understand how sheet metal is formed, even today. Mr. Keeler was—and remains—an icon in the world of metal forming. His knowledge, ability to mentor others and smiling face are sorely missed. As for me, filling the shoes of a man who was once described as an individual who “forgot more about sheet metal than most people know” is both intimidating and flattering. In any case, I will do my best to live up to the standard established by Dr. Keeler.
When I first started getting involved in training and consulting, my mentor, Mr. Edwin Stouten, used to tell me, “Prior to troubleshooting, designing, processing or consulting on a metal stamping process, it is essential that you answer these two questions: What is the material type and grade that the part is to be made from? What is the material’s thickness?” Knowing these two answers sets the stage for every decision you will make. This includes determining if the part actually can be made, the process steps, the die-design parameters and numerous other factors.
Making decisions without this pertinent information certainly is a high-risk maneuver. In my career as a consultant, I have witnessed dies be completely designed and built, only for the builders to find out that they are trying to defy the physical limits of the material. It is only after this expensive failure that they spend some time researching the material parameters. This, of course, typically ends up being a dollar short and a day late.