Menu
Batch CAD Cart (0) ▾
  • Cart is empty
  1. Click Here for Batch Download
Request Information Add to CAD Cart
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 31318M

Cone Part Number

 N/A X31318M

Cup Part Number

 N/A Y31318M

Design Unit

 N/A Metric

Cage Material

 N/A Stamped Steel

Dimensions

d - Bore

 N/A 90 mm3.5433 in

D - Cup Outer Diameter

 N/A 190 mm7.4803 in

B - Cone Width

 N/A 43 mm1.6929 in

C - Cup Width

 N/A 30.000 mm1.1811 in

T - Bearing Width

 N/A 46.5 mm1.8307 in

Abutment and Fillet Dimensions

R - Cone Backface "To Clear" Radius1 N/A 4.060 mm0.16 in
r - Cup Backface "To Clear" Radius2 N/A 3.05 mm0.12 in

da - Cone Frontface Backing Diameter

 N/A 117 mm4.61 in

db - Cone Backface Backing Diameter

 N/A 128 mm5.04 in

Da - Cup Frontface Backing Diameter

 N/A 182.12 mm7.17 in

Db - Cup Backface Backing Diameter

 N/A 164.08 mm6.46 in

Ab - Cage-Cone Frontface Clearance

 N/A 6.6 mm0.26 in

Aa - Cage-Cone Backface Clearance

 N/A 6.9 mm0.27 in
a - Effective Center Location3 N/A 13.2 mm0.52 in

Basic Load Ratings

C90 - Dynamic Radial Rating (90 million revolutions)4 N/A 84000 N18900 lbf
C1 - Dynamic Radial Rating (1 million revolutions)5 N/A 324000 N72800 lbf

C0 - Static Radial Rating

 N/A 421000 N94600 lbf
Ca90 - Dynamic Thrust Rating (90 million revolutions)6 N/A 119000 N26700 lbf

Factors

K - Factor7 N/A 0.71
e - ISO Factor8 N/A 0.83
Y - ISO Factor9 N/A 0.73

G1 - Heat Generation Factor (Roller-Raceway)

 N/A 169.3

G2 - Heat Generation Factor (Rib-Roller End)

 N/A 37.1
Cg - Geometry Factor10 N/A 0.114
  • 1 These maximum fillet radii will be cleared by the bearing corners.
  • 2 These maximum fillet radii will be cleared by the bearing corners.
  • 3 Negative value indicates effective center inside cone backface.
  • 4 Based on 90 x 106 revolutions L10 life, for The Timken Company life calculation method. C90 and Ca90 are radial and thrust values.
  • 5 Based on 1 x 106 revolutions L10 life, for the ISO life calculation method.
  • 6 Based on 90 x 106 revolutions L10 life, for The Timken Company life calculation method. C90 and Ca90 are radial and thrust values for a single-row, C90(2) is the two-row radial value.
  • 7 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 8 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 9 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 10 Geometry constant for Lubrication Life Adjustment Factor a3l.
By clicking Submit, you consent to the personal information you provide being used in the manner as described in our Privacy Notice, including access to that information by Timken personnel who may be located outside your home country. In addition, you agree that the CAD drawings are for your personal, one-time use only, and that you will not modify or create any compilation or derivative work using the CAD drawings or distribute or display the CAD drawings on any website or other media.