TimkenNA12581SW-90027Two-Row Tapered Roller Bearing Assembly – 13/16 in Bore, 3 in OD, Double Cup

Product Description

What this part is:

Timken NA12581SW-90027 tapered roller bearing assembly. Bore / Shaft Size: 13/16 in (0.8125 in, 20.64 mm). Outside Diameter: 3 in (76.2 mm). Bearing type: Tapered roller bearing assembly, two row. Number Of Rows: 2. Rolling Elements: Tapered rollers. Material: Bearing-quality alloy steel, through-hardened races and rollers. The assembly pairs matched cones on a common double cup, so both rows share one outer ring.

Decoding the designation:

NA — cone furnished for two-row and double-cup service, ground to the matched tolerances that a two-row assembly needs.

12581 — Timken inch cone series 125, the base number that fixes the roller path and the 13/16 in bore.

SW — the cone execution supplied in this assembly.

-90027 — Timken assembly number. It identifies the complete factory-matched build rather than any single component.

What these specs mean in practice:

Two opposed rows of tapered rollers carry radial load and thrust in both directions from one bearing position. A single double cup holds both raceways, which fixes the row-to-row spacing at the factory and removes the setting work a pair of separate single-row bearings would need. The 13/16 in bore against a 3 in outside diameter gives a large section for the shaft size, so the assembly carries a high load for its bore.

Quantity and configuration:

Unit Quantity: 1 Pc. One complete NA12581SW-90027 assembly per unit, supplied as a factory-matched build.

Mounting data:

Bore / Shaft Size: 13/16 in. Outside Diameter: 3 in. The cone bore mounts on the shaft journal and the double cup seats in the housing bore. Because the two rows sit in one outer ring, the housing needs a single straight bore rather than two separate cup seats.

Fitting notes:

The cones mount press-fit to a rotating shaft journal; the double cup takes a location fit in a stationary housing. Row spacing and internal setting are established in the factory build, so the assembly goes in as supplied.

Interchange guidance:

MPN Variants: NA12581SW-90027, NA12581SW 90027, NA12581-SW, NA12581SW, K38958, K312479. K38958 and K312479 are Timken component reference numbers carried on this assembly.

Assemblies in the NA12581SW-900xx family share the 13/16 in bore and 3 in outside diameter but differ in internal build, so the full dash number identifies the part.