SKF 628/8-2Z Metal Shielded Single Row Deep Groove Ball Bearing 8x16x5mm

The SKF 628/8-2Z shielded miniature deep groove ball bearing provides low-friction rotational support where both shaft diameter and housing space are limited. Its 8mm bore, 16mm outside diameter and 5mm width make it suitable for small precision assemblies requiring a compact bearing seat. The single row deep groove raceways accommodate radial loads and limited axial forces in either direction, subject to the bearing's rated capacity. SKF specifies a basic dynamic load rating of 1.33kN and a basic static load rating of 0.57kN. Compared with the extra-thin 618/8 bearing, this model has the same bore and outside diameter but an additional millimetre of width, so replacement requires checking the available axial space.

The 2Z designation identifies a metal shield on each side, rather than contacting rubber seals. These shields help retain the grease fill and reduce the ingress of larger dust particles while allowing lower-friction running. SKF lists a reference speed of 90,000rpm and a limiting speed of 45,000rpm; neither figure should be treated as an unconditional continuous operating speed, since load, lubrication, temperature and mounting conditions also matter. The bearing has normal (CN) radial internal clearance and a sheet metal cage. Although the 628/8-2Z shares its dimensions with the 628/8-2RS1, the contact-sealed alternative offers greater contamination protection at the expense of seal friction. Select the shielded version where the equipment specification favours speed and low resistance over enhanced exclusion of moisture or fine contaminants.

Typical Applications:

Miniature electric motor and instrument shafts

Precision guide rollers in clean environments

Small automation and positioning mechanisms

Compact light-duty pulley and drive assemblies

Miniature rotating components in measuring equipment