Real-World Precision Stamping: Dimensional Specs Are Not Enough

Most designers of stamped parts don’t need to be convinced of the value of specifying tolerances as a regular practice. This example in Machine Design illustrates why tolerancing is always a good idea. “A machine shop that sees an untoleranced diameter, without knowing the design intent, may apply a standard tolerance for three-decimal-place untoleranced dimensions, ±0.005 in. [which] may result in interference, where the hole is smaller than the shaft diameter, which prevents the parts from sliding together … if too large of an interference exists, it will degrade performance.” As the article notes, the end result is usually extra time and money to rework the parts.