3478/20

Manufacturer-published tapered-roller dimensions, load ratings, fatigue load limit, and limiting speed.

Bore d34.925 mmOutside diameter D79.375 mmOverall width T29.37 mmDynamic rating Cr109 kNKoyo calculation tool ↗

Live manufacturer specification row

Published specifications

Inch family

Designation: 3478/20
Family: Inch Tapered Roller Bearings
Bore d: 34.925 mm
Outside diameter D: 79.375 mm
Overall width T: 29.37 mm
Inner ring width B: 29.771 mm
Minimum corner radius r: 3.6 mm
Minimum corner radius r1: 3.2 mm
Dynamic load rating Cr: 109 kN
Static load rating C0r: 105 kN
Fatigue load limit Cu: 15.7 kN
Grease limiting speed: 5,200 rpm
Published row text: 3478/20 | 34.925 | 79.375 | 29.37 | 29.771 | 3.6 | 3.2 | 109 | 105 | 15.7 | 5200

Verification boundary

Do not infer interchange

Exact set architectureConfirm metric versus inch family, cone/cup identity, series, and complete designation.

Fits and geometryVerify shaft/housing seats, shoulders, fillets, preload/endplay, and mounting arrangement.

DutyCheck combined radial/axial loading, lubrication, speed, temperature, contamination, and required life.

Current manufacturer dataUse the linked JTEKT/Koyo calculation and CAD tools before ordering.

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