Gold tubing manufacturer dies redesign (Boston area)

Tom redesigned a sequence of drawing dies that had grown empirically over decades — some at 9% reduction, some at 35%+ — to a logical progression. Used as the on-page proof that even modern industrial die sequences were assembled by trial and error.

They made their tubes by a deep drawing process — just a great big long press coming in. Start out with a piece of karat gold and make it. They also would do gold-filled material, which is a clad material — clad on copper or brass, with gold on the outside. They asked me to redesign their dies, which is why I started thinking about this when you asked the question, was this all done empirically. If you looked at the dies, some of them — when you went from one die to the next, some of them had a less-than-9% reduction, and another one had a 35% reduction. There's no logic whatsoever. So I redesigned their dies for them. It's basically calculating logical steps of progression. Some of the dies at 40% might be cracking, giving high failure rates. The other ones at 9% could have been setting up stresses that actually could have been bad later on. Remember, I told you, you want to get a fair amount of deformation in. You don't want to do these little light passes. They can do more harm than good.

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