Hirobo HI2500050 3 x 8 x 4 mm Bearing Set, 2 pcs  [HI2500050]

3 x 8 x 4 mm Shielded Bearing Set

This RC-scale bearing set contains two 3 x 8 x 4 mm bearings, identified as 693ZZ to indicate metal shields on both sides. They fit as replacements in helicopter general parts where the specified bore, OD and width match the original items. The small size and shielded faces help keep contaminants out while permitting smooth rotation in low- to moderate-load places such as small drivetrains and rotor linkages.

Fitting notes: verify shaft and housing tolerances before installation, use a bearing press or a soft-faced driver that transmits force to the outer race only, avoid hammering the races, and check for free spin and minimal axial play before completing assembly. For maintenance, inspect the shields and manually spin the bearing to check for any roughness.

Included: 2 pcs, 3 x 8 x 4 mm, marked 693ZZ.