Timken281200-3Tapered Roller Bearing Cup – 12.000 in Outside Diameter, 1.6875 in Width, Class 3 Precision

Product Description

What this part is

Timken 281200-3 inch tapered roller bearing cup. Bearing Type: Tapered roller bearing cup — the outer race of a single-row tapered roller bearing. Series: 2812. Base Number: 281200. Outside Diameter: 12.000 in (304.8 mm). Overall Width: 1.6875 in (42.863 mm). Rolling Elements: Tapered Roller. Number Of Rows: 1. Item Weight: 16.300 kg (35.8 lb).

Decoding the designation

281200 — Timken base cup number, 12.000 in outside diameter. The outside diameter is a whole inch, which is the convention across Timken’s large-bore industrial cups.

*3 — Timken Precision Class 3. Tighter running and mounting tolerance than standard class, giving lower running vibration and closer location in the housing bore. The same class is written 281200-3, 281200 *3 and 281200 #3.

What these specs mean in practice

e Factor: 0.36. Y Factor: 1.67. Geometry Factor (Cg): 0.112. A 1.6875 in ring width on a 12 in outside diameter is a thin section for the diameter, the shape used on large slow-turning shafts where the raceway has to be big and the housing shallow.

Mounting data

Maximum fillet radius on the mating housing: 3.30 mm (0.130 in). Housing Backing Shoulder Diameter, frontface (Da): 285.50 mm (11.24 in). Housing Backing Shoulder Diameter, backface (Db): 278.89 mm (10.98 in).

Quantity and configuration

Unit Quantity: 1 Pc. Cup only. Matching cones are the Timken EE280626 and EE280702.

Interchange guidance

281200 is a Timken large-bore industrial cup number. It is a low-volume size, and the Timken cone-and-cup pairing is the established fit. Precision Class 3 is a Timken tolerance grade, a tighter band than the plain 281200.