Ode to the stamping die

No other tool, when built for mass production, can reliably and repeatedly form parts in long runs and large volumes like stamping dies. Its permanence, durability, and ability to perform repeatedly are its hallmarks. Getty Images

"The die is cast.” Although this phrase does not refer to a stamping die, which typically is not cast but rather machined (unless it is a prototype die), its sentiment is relevant to metal stamping.

The phrase purportedly goes back to the days of Julius Caesar and refers to the singular version of dice, according to dictionary.com and other sources. The expression comes from the Latin “Alea jacta est’’—"the dice have been thrown.” It was alleged to have been said by Caesar when he crossed the Rubicon and invaded Italy in 49 B.C. The superstitious Caesar declared that he had to abide by the result of a throw of the dice.

Essentially, it means that a decision or course of action has been determined and cannot be changed.

The Die Is Milled

A stamping die has been defined as a two-part precision tool that cuts, impresses, and forms sheet metal into a desired shape or profile when its mating parts are joined around the sheet in a press. The development of the die alleviated the painstaking work of making a product one at a time with a hand tool.

The stamping die’s origins are varied, depending on which stepping stone you consider the beginning. Was it when humans began extracting and smelting metals and forming them into metal tools? Was it the ancient Greeks who struck a metal blank between two die halves to coin? Some credit a German locksmith in the 15th century who used them to manufacture hinges. In 1796 a patent was granted to a French toolmaker for dies for punching and drawing sheet metal. Grand Rapids, Mich., engineer Ed Stouten is widely credited for devising the progressive die concept in 1953.

Manufacturers have tried to make inroads with plastics and other nonmetallic materials to undercut the die’s complexity and shorten the time to build a die. Yet, no other tool, when built for mass production, can reliably and repeatedly form parts in long runs and large volumes like stamping dies. Once finished, a production stamping die can produce millions of nearly identical parts rapidly.

Although a die can be altered, at least to some degree with additional milling, its permanence, durability, and ability to perform repeatedly are its hallmarks.

Die Emphasis in Nov./Dec. Issue

In the November/December edition of STAMPING Journal, we wrap up the year with several articles centering on the die.

We delve into sensoring the die, vision systems that keep an eye on the die, managed lubricating systems for the die and parts, and, in our buyers’ guide, die handling.

The die sensor article, “Sensors for stamping: Primer” is intended to provide an overview for beginners or a refresher for veterans, outlining which types of sensors are best for each application.

Vision systems are designed to protect tools and prevent die damage. “Vision system protects tools, prevents damage” describes how they can help stampers to understand malfunctions and their causes, as well as the entire stamping process.

Our lubrication application article, “Lubricant reduction through precision dosing,” describes how optimal lubricant application makes for more efficient die and stamping processes and eliminates oil waste.

Die Science columnist Art Hedrick addresses those deep-drawing circumstances that defy the lubrication laws and discusses how heat and friction affect the process.

Many people view tool- and diemaking as a bottleneck, considering that the process can take weeks, even months. Can 3D printing of some die components help accelerate the diemaking process? Our Engineering Angle column reveals research on just that topic.

So here’s to the mighty die. Long live.

Got thoughts? I’d love to hear from you. kateb@thefabricator.com