Die striking or stamping is the process in which a piece of metal is placed between two plates (dies) and struck with a heavy force. The striking force is usually applied by a press; power press, hydraulic press, air press, or old style “drop hammer”. The amount of force required is determined by the size of the part to be struck, the thickness of the part, the type of metal used, and the complexity of the design. Sometimes the piece to be struck must be hit more than once. Since metal becomes harder after being hit (called work hardening), it is common practice to anneal (soften) the piece between “blows”.
The die has a pattern cut into the special steel alloy metal to provide the detail your piece requires. In most cases, the other die, called the back die, is flat and may or may not have a pattern cut into it. Since these dies are struck with tremendous force in order to create the imprint, they must be properly heat treated to withstand the pressure without cracking. For large production runs and in order to prevent production delays, a second backup die is often made.
The second tool required in die striking is the trim tool. The trim tool is a steel alloy cutter (like a cookie cutter) that cuts the shape out of the die struck metal. As you can imagine, some shapes are easy and inexpensive to make; whereas more complex shapes are difficult and expensive. If there are holes in your part, then additional “piercing” tools will be required. A die struck piece may also be curved or “dapped”. In this case, a curving tool is needed.
In recent years in the United States, master artisan tool and die makers have dwindled in number. Domestic talents have largely been absorbed in more exacting tooling in aerospace and other industries. Attempts have been made to transfer the required knowledge with computer aided design techniques. Domestically, our industry consists of many family owned and operated stamping businesses, sometimes called finding houses. Each factory has its own specialty. We use our extensive knowledge and experience to select among these dwindling companies the best factory to use for your job.
With increased globalization, much of the production in this field is done overseas. These factories began in Taiwan back in the 1980’s, moved to Korea, and finally China. Like most manufacturing, this was originally driven by the search for lower costs. As recognition jewelry manufacturing has matured, the quality of manufacture by a reputable overseas manufacturer is in many case equal or better than a comparable set of factories in the United States. However, as fuel costs increase and China continues its massive growth, the huge cost differences between domestic and overseas production has narrowed.