For years, press fits have been used to join parts rigidly. Today's emphasis on quality control demands full use of modern control systems and techniques that monitor and verify press force and all other aspects of pressing operations. This article explains these techniques and describes how they ensure product quality.
Press fits are everywhere. According to Denny Lytle, product manager at BalTec Corp. (Canonsburg, PA), they're used in the tele-communications and computer industries, and in automobiles, airplanes, office equipment and consumer goods. But what exactly is a press fit?
Press fitting refers to two parts being pressed together and making an interference fit. An interference fit occurs when the inner diameter of the hole is slightly less than the outer diameter of the part being inserted. When the two parts are pushed together, they stick. According to Paul Bussman, industrial products manager for Kistler Instrument Corp. (Amherst, NY), "Press fitting is a lower quality fitting process. However, once a press fit is in place, it's not going to come loose."