BowerSingle-Row Tapered Roller Bearing Cone and Cup Set, 1-3/8 in Bore, 3.123 in Outside Diameter, 1.1563 in Wide, 2 Pcs

Product Description

What this part is

A single-row inch-series tapered roller bearing, supplied as a matched cone and cup set on the 3482/3426 numbering — 1.3750 in bore, 3.1230 in outside diameter, 1.1563 in assembly width. Tapered roller bearings put the roller axis, the raceway and the bearing axis on a common apex, which means they carry heavy radial load and heavy thrust in one direction at the same time. The cup is a separate ring, so the two halves ship as two pieces and are set to clearance or preload at assembly.

Decoding the designation

3482 – the cone: the inner ring, complete with its roller set and cage.
3426 – the cup: the separate outer ring.
The slash between them is Timken and AFBMA convention for a complete two-piece bearing. A bare 3482 would be a cone on its own; a bare 3426 would be a cup on its own.

What these specs mean in practice

Because the cup is loose, a tapered roller bearing has no internal clearance until you build it. Setting is the job: two of these bearings mounted back to back or face to face on a shaft are adjusted against each other with shims, a spacer or a nut until you have the specified end play or preload. That setting, not the bearing itself, determines whether the assembly runs cool and lasts or runs hot and fails, which is why the same part number can give wildly different service life in careful and careless hands.

The K factor of 1.6 describes the steepness of the cup angle and tells you how the bearing splits a combined load. A higher K is a shallower cup and a more radially biased bearing; a lower K is steeper and takes proportionally more thrust. Paired with the e value of 0.37 and Y of 1.49–1.64, that is what you plug into the equivalent-load calculation when the applied load is not purely radial.

Note that the cone width, 1.1721 in, is slightly greater than the 1.1563 in assembly width. That is normal for this design — the cone backface rib stands proud of the cup — so a caliper across the bore side will read the larger figure while the catalogue T dimension is the smaller one. Use T for stack-up calculations.

Published ratings and mounting data

Cone bore d: 1.3750 in (34.925 mm)
Cup outside diameter D: 3.1230 in (79.324 mm)
Assembly width T: 1.1563 in (29.370 mm)
Cone width B: 1.1721 in (29.771 mm)
Cup width C: 0.9375 in (23.813 mm)
Rows: 1, tapered rollers
Dynamic radial rating C90: 6,100 lbf — C1 23,500 lbf
Dynamic thrust rating Ca90: 3,820 lbf
Static radial rating C0: 26,800 lbf (119 kN)
K factor: 1.6 — e 0.37, Y 1.64
Cage: stamped steel
Closure: open

Quantity and configuration

Two pieces per set: one 3482 cone with rollers and cage, and one 3426 cup. Both are included. No shims, spacers, lock nuts or seals are supplied.

Interchange guidance

The 3482 cone and 3426 cup are standard AFBMA inch numbers used across the industry, so Timken 3482/3426, Bower and BCA 3482/3426, SKF 3482/3426, NTN 4T-3482/3426, Koyo 3482/3426 and Fersa 3482/3426 all describe the same size. Alternative cups that mate with the same 3482 cone and share the 3.1230 in outside diameter, differing in width: 3420, 3422 and 3431, plus the flanged 3420-B and the double cups 3423D and 3424YD for two-row TDO builds. Check the width against your housing bore depth before using any of them.