In manufacturing, ironclad formulas for success are hard to come by. This is especially relevant for press-fit assembly, a process whereby one part is inserted tightly into a hole in another part with a single quick stroke (1 to 2 seconds). Design engineers use many formulas to estimate the required force and related pressures and stresses for each press-fit application. However, those calculations can never replace real-world lab testing, or trial and error on the production line.
“Formulas can provide a starting point in the process of designing parts for press-fit, but they don’t take into account the many variables that come into play during assembly,” says Chuck Rupprecht, general manager at BalTec Corp. “Factors like inconsistent material quality, different surface finishes and ambient humidity can result in calculations that are way off. The truth is, you must install actual parts to determine the proper material and force requirements for an application.”