The xiros® polymer ball bearings are single-row grooved ball bearings based on DIN 625. The lubricant-free and maintenance-free ball bearing consists of four components: the outer ring; the inner ring; the cage; and the balls. The inner and outer rings are made of igus® tribopolymers to maximise service life and minimize coefficients of friction. In contrast to metallic ball bearings, xiros® polymer ball bearings manage absolutely without lubrication. For this reason they are suited for a multitude of applications that depend not on extreme rotary speeds or loads, but just on lubricant-free application in contrast to permanently lubricated metallic ball bearings.