The nomenclature 30x42x7 describes the oil seal's three critical dimensions the inner diameter (ID), outer diameter (OD), and width (W). Specifically, this oil seal features an inner diameter of 30 mm, an outer diameter of 42 mm, and a width of 7 mm. These measurements indicate that it is designed to fit into a specific space within a machine, preventing the leakage of fluids, particularly oil, from critical components like shafts and housings.
