XTB-curve roller is composed of a stud used as the tray of a group of rollers and a thick wall outer ring. The shoulder of the stud and the surface retaining ring on the stud form the guiding faces on the two sides of the outer ring. When the curve rollers are running on the plain tray or CAM wheel, the inner stress on the rollers will increase due to the deformation of the outer ring. Therefore the rated load should be selected as curve roller column in this operational case. Structure: KR curve rollers radically guided by the retaining edge and ring KR. . . Pp curve rollers with sealing ring KRE curve rollers with eccentric sleeve KRE. . . Pp curve rollers with eccentric sleeve and retaining sleeve KRV curve rollers radically guided by the retaining edge and ring, full complement needle roller type KRV. . . Pp curve rollers with sealing ring KRVE curve rollers with eccentric sleeve KRVE. . . PP curve rollers with eccentric sleeve and retaining sleeve NUKR curve rollers axile guided by rolling bodies, full roller type NUKRE curve rollers with eccentric sleeve