A precision spindle unit for low friction performance includes a tubular housing surrounding a shaft, and first and second rolling bearings mounted on the shaft within the housing. The first bearing is axially arrested between the flange of a locking washer fixed to the shaft and a shoulder on the shaft. A second locking washer is fitted to the shaft, and a resilient member is provided between the second locking washer and a side of the inner race ring of the second bearing. The axially inwardly facing side of the outer race ring of the second bearing engages an inwardly projecting shoulder in the housing, with the second bearing being biased between the resilient member and the inwardly projecting shoulder. The locking washers define a slot seal at each axial end of the housing to provide a seal at the outwardly facing sides of the first and second bearings.