Precision Bearings

Timken Precision Bearings

When you choose Timken® bearings for your applications, you receive products made and backed by a global leader known for quality, reliability, and performance. Quality begins long before our machine tool bearings are manufactured and extends long after they are installed. We design bearings for optimum performance and long life.

We are not only on Earth , We are on Mars as Well

Timken® precision bearings have equipped every planetary rover on Mars, including NASA’s most recent: Curiosity. Learn more about the epic application challenges solved by a 1/4 inch miniature Radial Ball Bearing capable of operating at 100,000 rpm, along with the rigorous testing and validation that made this mission possible.

Types Of Precision Bearing

Super Precision Ball Bearings, Super High Precision (ABEC 7/9; ISO P4/P2) : Timken super precision ball bearings manufactured to the MM/ MMV(P4S) tolerance class operate with running accuracy and performance levels meeting ABEC 9 (ISO P2) standards yet maintain other features at ABEC 7 (ISO P4) level for cost-effectiveness. Bore and O.D. surfaces are coded in micron units for the convenience of the discriminating machine tool builder striving for optimum fitting of crucial spindle components. 

Ultra-Precision Ball Bearings (ABEC 9, ISO P2) : Timken MMX(P2) super precision ball bearings, with closer tolerances and running accuracies than ABEC 7 (ISO P4) bearings, are made to ABEC 9 (ISO P2) tolerances. Bearings produced to these tolerances are generally used on ultra-high-speed grinding spindles designed for tight dimensional tolerances and superfine surface finishes. Contact your Timken representative for availability of product range. 

Precision Tapered Roller Bearings (Class C/S/3, B/P/0 and A/00) : The more demanding the precision objective, the more accurate the bearing must be. Timken provides three tapered roller bearing classes, in both metric and inch systems, that cover the full range of precision application requirements. In ascending order of accuracy, they are identified in the metric system as Class C/S, B/P, and A, while in the inch system as Class 3, 0, and 00. 

Precision Plus TM Tapered Roller Bearings (Class 000/AA)  : To further minimize the influence of variations, Timken offers a fourth level of precision tapered roller bearing manufacture so tightly controlled that it goes beyond the grade levels of both ISO and ABMA standards. Timken’s Precision PlusTM line offers (metric- nominal) AA level and (inch-nominal) 000 tapered roller bearings in various sizes and styles. 

Standard Applications

  • Precision rotary and indexing tables for machine tools 
  • Vertical and horizontal boring mills 
  • Vertical grinding machines
  • Rotary surface grinding machines 
  • Large gear hobbing machines 
  • Turrets – gun and radar 
  • Large telescopes (radio and optical) 
  • Swiveling cameras
  • Steering pivots and castors
  • Pivots where height is restricted 
  • Microscope tables 
  • Crane center pivots 
  • Swiveling bogies
  • Welding manipulators
  • Large tanker mooring buoys 
  • Rotary assembly jigs
  •  Industrial robots 

Design Features & Advantages

Two rows of rollers in the space of oneLess housing material
Cross section occupies little space Machining requirements reduced 
 Reduced cost 
Roller configuration gives wide effective spread Maximum accuracy of rotation 
Line contact on roller and raceway High stability 
 Greater tilting stiffness 
Adjustable design for optimum preload Longer expected bearing life 
 Maximum rigidity 
 Minimum runout 
Relubrication ability – lubricant, fed between the single races, may pass out at each side of the bearing Allows lubricants and contaminants to be purged 
Nylon separators Low inertia 
 Low running torque 
Case-hardened steel Provides tough, shock-resistant core and hard, wear-resistant surfaces 

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