SKF 604-2Z Metal Shielded Single Row Deep Groove Ball Bearing 4x12x4mm

The SKF 604-2Z metal shielded deep groove ball bearing provides precision rotational support for machinery where a 4mm shaft diameter and minimal installation space are essential. Its compact 4mm bore, 12mm outside diameter and 4mm width make it suitable for miniature electric motors, instrument drives and small pulley mechanisms. The single row deep groove raceways accommodate predominantly radial loading together with limited axial forces in either direction. SKF catalogue specifications give a basic dynamic load rating of 0.806kN and a basic static load rating of 0.28kN. These ratings should be considered when assessing bearing fatigue life and operating loads, particularly in miniature assemblies where dimensional constraints leave limited scope for increasing bearing size.

The 2Z designation identifies two non-contact metal shields, one on each side of the bearing. These shields help retain the factory-applied grease and reduce the entry of dust and debris while avoiding the continuous rubbing friction associated with rubber contact seals. SKF specifies a reference speed of 120,000rpm and a limiting speed of 60,000rpm; these are catalogue speed ratings rather than guaranteed operating speeds under every loading and temperature condition. Because metal shields do not provide the same contamination resistance as contact seals, the 604-2Z is best suited to relatively clean operating environments. The bearing features normal (CN) radial internal clearance and a sheet metal cage. During installation, use carefully controlled fits and avoid transferring mounting forces through the balls. For replacement work, confirm the full 604-2Z designation and distinguish it from the stainless-steel W 604-2Z variant.

Typical Applications:

Miniature electric motors and precision motor drives

Compact measuring instruments and mechanical indicators

Small pulley, guide wheel and roller assemblies

Light-duty automation and positioning mechanisms

Model engineering and miniature transmission systems