SKF Y-bearings (insert bearings): series and bores

The letters name the series: YAR, YET, YEL and UC are not equivalent even when they share a size, because the locking system and the inner ring width change. In YAR 203-2F and YET 203, the number 203 is the size; the bore is the standard one for that size. When the shaft is different, the designation says so with an extra block: YAR 203/12-2F is the same size with a different bore.

In the UC series the same happens with a hyphen: UC 205 and UC 205-16 have the same outside and different bores, one metric and one in inches. That is why an insert is not ordered by size alone. The blocks at the end, such as 2F, describe the execution and are copied in full.

The insert settles inside the housing thanks to its spherical outside, which absorbs mounting misalignment, not a bent shaft or a loose base. If the previous one had a short life, look at how the shaft was marked: the prints left by the grub screws or the collar show whether the locking came loose. A scored or undersized shaft shortens the life of the replacement even when the code is right.

When replacing the insert alone, check that the spherical seat of the housing is sound and that the grease fitting lines up with the relubrication hole in the outer ring. When the unit works with frequent washdown or fine dust, write down the complete execution of the removed insert instead of choosing a similar one.

Give us the designation exactly as engraved on the inner ring, the quantity and the actual shaft diameter measured with a caliper. If it cannot be read, measure the bore, the outside diameter and the inner ring width, and tell us how it is locked: with two grub screws, with an eccentric collar or with a sleeve. The designation of the housing it sits in also helps, because it narrows down the possible series. A photo of the side, where the seal is visible, completes the order.