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
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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

Key Dimensions

Series

 N/A M255400

Cone Part Number

 N/A M255449H

Bore (d)

 N/A 11.375 in288.925 mm
Dynamic Radial Load Rating - 90M Revs (C90) 1 N/A 79500 lbf354000 N
Dynamic Radial Load Rating - 1M Revs (C1) 2 N/A 307000 lbf1360000 N
C1 - Dynamic Radial Rating (Two-Row, 1 million revolutions)3 N/A 534000 lbf2380000 N
Dynamic Radial Load Rating 2-Row - 90M Revs (C90-2row) 4 N/A 138000 lbf616000 N
K Factor 5 N/A 1.73

Other Dimensions

Inner Ring Width (B)

 N/A 3.0625 in77.788 mm
Max Shaft Fillet Radius6 N/A 0.25 in6.4 mm

Shaft Backing Shoulder Diameter - Frontface (da)

 N/A 12.24 in311 mm

Shaft Backing Shoulder Diameter - Backface (db)

 N/A 12.48 in317 mm

Cage Location Relative to Frontface (Ab) 

 N/A 0.22 in5.6 mm

Cage Location Relative to Backface (Aa)

 N/A 0.15 in3.8 mm
Effective Center Location7 N/A -0.16 in-4.1 mm

Weight

 N/A 177.09 lb80.329 Kg

Ratings

Static Radial Load Rating (C0)

 N/A 567000 lbf2520000 N
Ca90 - Dynamic Thrust Rating (90 million revolutions)8 N/A 46000 lbf205000 N

Factors

G1 Factor

 N/A 2301.3

G2 Factor

 N/A 287.6
Geometry Factor (Cg)9 N/A 0.172
  • 1 Based on 90 x 106 revolutions L10 life, for The Timken Company life calculation method. C90 and Ca90 are radial and thrust values.
  • 2 Based on 1 x 106 revolutions L10 life, for the ISO life calculation method.
  • 3 Based on 1 x 106 revolutions L10 life, for the ISO life calculation method.
  • 4 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.
  • 5 These factors apply for both inch and metric calculations. Consult your Timken representative for instruction on use.
  • 6 These maximum fillet radii will be cleared by the bearing corners.
  • 7 Negative value indicates effective center inside cone backface.
  • 8 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.
  • 9 Geometry constant for Lubrication Life Adjustment Factor a3l.