Menu
Discover the New “My Dashboard” Experience

Join Eric Stasiowski, manager – online marketing & ecommerce, to see how you can save key items like documents, bearings, and distributor locations directly to your account.

View Video
Analyze Bearing Performance in an Application with Timken ® Syber ® Bearing System Designer

A powerful software tool that combines calculators and configurators to assist you with application design, bearing selection, installation, and troubleshooting. It’s free, easy-to-use, and accessible 24/7.

Learn More
Simplified Gear Force Analysis

Alex Waye, Timken Application Engineer, shows you how to instantly compute tangential, radial, and axial forces for better design decisions.

View Video
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 990000

Cone Part Number

 N/A EE991201

Cup Part Number

 N/A 992550

Design Unit

 N/A Inch

Cage Material

 N/A Pin-Type

Dimensions

d - Bore

 N/A 12 in304.8 mm

D - Cup Outer Diameter

 N/A 25.5000 in647.700 mm

B - Cone Width

 N/A 4.7500 in120.650 mm

C - Cup Width

 N/A 3.5000 in88.900 mm

T - Bearing Width

 N/A 5.5000 in139.700 mm

Abutment and Fillet Dimensions

R - Cone Backface "To Clear" Radius1 N/A 0.530 in13.460 mm
r - Cup Backface "To Clear" Radius2 N/A 0.530 in13.46 mm

da - Cone Frontface Backing Diameter

 N/A 14.17 in360 mm

db - Cone Backface Backing Diameter

 N/A 15.12 in384 mm

Da - Cup Frontface Backing Diameter

 N/A 23.39 in594.11 mm

Db - Cup Backface Backing Diameter

 N/A 21.50 in546.10 mm

Ab - Cage-Cone Frontface Clearance

 N/A 0.92 in23.4 mm

Aa - Cage-Cone Backface Clearance

 N/A 1.01 in25.7 mm
a - Effective Center Location3 N/A 2.17 in55.1 mm

Basic Load Ratings

C90 - Dynamic Radial Rating (90 million revolutions)4 N/A 137000 lbf609000 N
C1 - Dynamic Radial Rating (1 million revolutions)5 N/A 528000 lbf2350000 N

C0 - Static Radial Rating

 N/A 790000 lbf3520000 N
Ca90 - Dynamic Thrust Rating (90 million revolutions)6 N/A 203000 lbf903000 N

Factors

K - Factor7 N/A 0.67
e - ISO Factor8 N/A 0.87
Y - ISO Factor9 N/A 0.69

G1 - Heat Generation Factor (Roller-Raceway)

 N/A 2353.6

G2 - Heat Generation Factor (Rib-Roller End)

 N/A 161.7
Cg - Geometry Factor10 N/A 0.23
  • 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.