TimkenSingle-Row Tapered Roller Bearing, Cone and Cup, 1-3/8 in Bore x 3-5/16 in OD

Product Description

What this part is

A Timken 3581/3530M single-row tapered roller bearing, supplied as both halves together: the 3581 cone with its rollers and cage, and the 3530M cup. Bore 1-3/8 in, outside diameter 3-5/16 in.

Quantity and configuration

1 Set — one cone and one matching cup, which is one complete bearing.

Decoding the designation

Timken writes a tapered roller bearing as cone number over cup number. 3581 is the cone and fixes the bore, the cone width and the raceway angle. 3530 is the cup and fixes the outside diameter and the matching outer raceway, with M a Timken variant marking on that cup. Either half can be ordered on its own by its own number.

What these specs mean in practice

Tapered roller geometry carries high radial load together with substantial thrust in one direction through the raceway angle, which is why the type is fitted in pairs facing opposite ways so the shaft is held both ways. At 1-3/8 in bore in a 3-5/16 in outside diameter this is a heavy section for the bore — a lot of roller length in a small shaft size, which is the classic wheel-end and pinion-head proportion where load is high and speed is moderate.

Interchange guidance

3581 and 3530 are industry-standard numbers; a cone marked 3581 and a cup marked 3530 from another tapered roller bearing maker are the same specification. Adjacent numbers in the 3500 block are different bores or outside diameters and are related sizes rather than substitutions.