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

The letters give the series. YAR, YET, YEL and UC are not interchangeable even at the same size, because the locking method and the width of the inner ring are different. In YAR 203-2F and YET 203, 203 is the size and the bore is the one standard for it. When the shaft differs, an extra block appears: YAR 203/12-2F keeps the size and changes the bore.

UC uses a hyphen for the same purpose. UC 205 and UC 205-16 share the outside dimensions but not the bore: one is metric, the other inch. So you cannot order an insert by size only. End blocks such as 2F describe the execution; copy them in full.

The spherical outer surface lets the insert align itself in the housing. That absorbs misalignment from mounting, but it will not make up for a bent shaft or a loose base. If the last insert failed early, check the shaft for marks: what the set screws or collar left behind tells you whether the locking slipped. A scored or undersized shaft will shorten the new insert's life even with the correct part number.

If you change only the insert, make sure the housing's spherical seat is in good shape and that the grease fitting lines up with the relube hole in the outer ring. For units exposed to frequent washdown or fine dust, record the full execution of the insert you removed rather than picking one that looks close.

Send the designation as it is marked on the inner ring, the quantity and the actual shaft diameter measured with calipers. If the marking is gone, measure the bore, the outside diameter and the inner ring width, and tell us the locking method: two set screws, an eccentric collar or a sleeve. The designation of the housing narrows the possible series, so include it. A photo of the side showing the seal rounds out the request.