‘滚珠’ literally means ‘rolling bead’ — 滚 (gǔn) means ‘to roll’ or ‘to tumble’, and 珠 (zhū) means ‘bead’ or ‘pearl’. Together, they form a technical compound referring to the small, spherical metal elements inside a ball bearing, which reduce friction between moving parts by rolling rather than sliding. Though the word itself contains no mechanical terminology, it’s widely used in engineering, manufacturing, and repair contexts.

In everyday speech, 滚珠 is rarely used alone; it typically appears in compounds like 滚珠轴承 (gǔn zhū zhóu chéng, ‘ball bearing’) or 滚珠丝杠 (gǔn zhū sī gǎng, ‘ball screw’). While 珠 can evoke imagery of pearls or animal eyes (e.g., 鱼珠 ‘fish eye’), in this term it strictly denotes a precision-engineered sphere — not a biological or decorative object. The term emphasizes function (rolling motion) over material or origin.