The Timken Company
The Timken Company
4500 Mt Pleasant St. NW
N. Canton, OH 44720
Phone: (234) 262-3000
E-Mail: CustomerCAD@timken.com • Web site: www.timken.com
Print Back
This is the most basic and most widely used type of tapered roller bearing. It consists of two main separable parts: the cone (inner ring) assembly and the cup (outer ring). It is typically mounted in opposing pairs on a shaft.
Unit of Measure

Specifications

Series

 N/A 31308M

Cup Part Number

 N/A Y31308M

Design Units

 N/A METRIC

Dimensions

D - Cup Outer Diameter

 N/A 90 mm3.5433 in

C - Cup Width

 N/A 17 mm0.6693 in

Abutment and Fillet Dimensions

r - Cup Backface "To Clear" Radius1 N/A 1.52 mm0.06 in

Da - Cup Frontface Backing Diameter

 N/A 86.40 mm3.40 in

Db - Cup Backface Backing Diameter

 N/A 75.95 mm2.99 in

Factors

K - Factor2 N/A 0.71
e - ISO Factor3 N/A 0.83
Y - ISO Factor4 N/A 0.73

G1 - Heat Generation Factor (Roller-Raceway)

 N/A 22.9

G2 - Heat Generation Factor (Rib-Roller End)

 N/A 10.3
Cg - Geometry Factor5 N/A 0.091
  • 1 These maximum fillet radii will be cleared by the bearing corners.
  • 2 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 3 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 4 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 5 Geometry constant for Lubrication Life Adjustment Factor a3l.