Timken Precision Bearings

Ultra-precision equipment requires more than standard bearings can deliver. Our extensive range of Timken® precision bearing assemblies, designed for the critical tolerances demanded by precise applications, offer superior rotational accuracy, consistency and rigidity.

Aerospace Bearings

We make the majority of Timken® aerospace bearings using vacuum-arc melt 52100 or VIM-VAR M-50 steel, typically manufactured to ABEC/RBEC 5 tolerances with high-strength machined cages to meet industry requirements.

Ball

Timken’s ball bearings for aerospace applications are specifically designed to withstand radial, thrust, moment, reversible thrust or combination loads. Our offering includes two Conrad configurations (types HK and HD) and two angular contact configurations (types HA and HT). Bearings may be supplied as single units or in preloaded sets. Size range: 10mm to 600 mm OD Design Attributes: HK series is designed to handle heavy loads and has high-strength Conrad separator options that can manage severe loads and speeds. HD series features an innovative fractured outer ring design that allows for maximum ball complement in a radial deep-groove bearing. This provides significant improvements in dynamic load capacity and predicted service life. HA series has a non-separable design with counter-bored outer rings and one-piece, high strength separators. Ideal for preloaded and/or thrust-type applications. Options include deep-groove outer and relieved inner races for ultra-high-speed applications. HT series is a high-performance line featuring full deep-groove outer rings, one-piece, high strength separators and two extra-deep-groove inner ring halves. Ideal for use on high-speed shafts with reversing thrust loads. Applications: Turbine engines and transmissions for aerospace applications

Cylindrical Roller

All cylindrical roller bearing configurations (except RAA) provide precision control of the rollers for operation over a wide range of speeds with precision-ground, double-ribbed guide flanges on one ring. These roller bearings are found in turbine engine mainshaft, transmission and gearbox applications with high radial loads. Size range: 22 mm to 300 mm OD (special designs up to 600 mm are available) Design Attributes: RF and RJ configurations are designed for applications requiring axial position control or limited thrust capabilities in one direction. For applications operating at higher loads and speeds, the RJ configuration is designed for easier lubrication with an oil jet onto the inner race. Types RU and RN are full-floating configurations that allow limited axial motion during operation. RN is less prone to slip or skid under lighter loads or varying loads at high speeds. RU is easier to lubricate under heavier loads. Types RUS and RNH bearings are used in integral designs where the rollers run directly on a hardened and ground shaft or housing. Performance characteristics are similar to RU and RN. The RAA configuration has single-ribbed inner and outer rings and performs under low speeds or oscillating conditions. It has high guide flanges to accept some thrust in one direction. Applications: Turbine engine mainshafts Transmissions Gearboxes

Miniature and Super Precision

The quality steel, tolerances and features of Timken® miniature bearings meet demanding performance requirements. Our super precision ball bearings, which surpass ISO/ABMA criteria, also maximize machine performance.

Precision Assemblies

Timken precision bearing assemblies are high performance units designed for the critical tolerances required in machine tool, health and aerospace applications. Ball Screw Support Bearings Timken® Fafnir® ball screw support bearings are specially designed with steep contact angles and offer high levels of stiffness for ball screw application requirements. X-Ray Assemblies Timken bearings for use in x-ray equipment are made from high hardness tool steels, with special coatings and unique designs to extend the life and improve performance the performance of x-ray tubes. Custom Integrated Assemblies Timken can create custom bearing assemblies to solve a variety of application challenges, from specific performance in a non-standard bearing size to survival in a hostile environment.

Machine Tool Bearings

Timken® machine tool bearings address application needs for rotational accuracy, consistency and rigidity, providing long life, extreme stiffness and precision even with very high loads.

Deep Groove Ball Bearings	Our deep groove ball bearings deliver reliable performance in a wide range of applications and conditions. With super-finished raceways and controlled geometries, our premium design helps ensure consistent quality. Our portfolio includes standard, thin section, narrow, wide and miniature and extra-small deep groove ball bearings that span 3 mm to 400 mm bore sizes. The extended product line includes a complete offering of open, shields, seals and snap ring combinations. Easy Interchange Designed as metric bearings, our deep groove ball bearings follow ISO standards and are dimensionally interchangeable with competitor metric products. Premium Lubricants For reduced torque and a quieter operation, Mobil Polyrex™ EM premium lubricant comes standard on all Timken sealed and shielded deep groove ball bearings. This grease has a temperature range from -29° C to 177° C. Brass Cage Availability Deep groove ball bearings with brass cages (available in select sizes) can deliver extra strength and durability in the most unrelenting conditions: extreme shock loads, high vibrations and high forces due to acceleration. Quiet Running for Electric Motor Quality Deep groove ball bearings are frequently used in electric motor applications to minimize vibration and noise. To meet our long-standing electric motor quality guidelines we designed in: Super finishing on raceways to reduce friction Preferred clearance designation (C3) Premium grease for high performance, low torque and less noise
Angular Contact Ball	Timken® angular contact ball bearings are designed for combination radial and axial loading. Single-row bearings have high thrust capacity in one direction. Some single-row bearings are specifically designed for duplex mounting in sets for maximum performance. Double-row Conrad bearings can accommodate thrust in both directions. Size Range: Single-row: 10 mm – 150 mm (0.3937 in. – 5.9055 in.) bore Double-row: 12 mm – 150 mm (0.4724 in. – 5.9055 in.) bore Design Attributes: Specific geometry of angular contact bearing raceways and shoulders creates ball contact angles that support higher axial loads. Expanded options include special lubricants, cage materials, preloads and coatings for additional corrosion resistance. Applications: Angular contact ball bearings are engineered for use in high-speed, high precision applications for: Agriculture Chemical General industry Utilities
Ball Screw Support Bearing	Our broad line of Timken® Fafnir® ball screw support bearings includes single- and double-row designs with a variety of mounting configurations. We offer flanged and non-flanged series for both standard and rotating nut mountings. Housed cartridge and pillow block units facilitate bolting to machine tool surfaces. Design Attributes: Materials include clean steel for longer service life. Incorporates tighter preload tolerances for chatter-free cutting and tighter width tolerances for easy fit without regrinding end caps. Innovative cage design permits additional balls for higher load capacity. Features ABEC 9/ISO P2 axial running tolerances to deliver maximum accuracy for precise tool positioning and repeatability. Double-row series has integral, low-torque contact seals to exclude contaminants for reliable operation and extended service life. Available in flanged (MMF) and nonflanged (MMN) series, simplifying installation for both standard and rotating nut mountings. Applications: Motion control for grinding, milling and machining centers
Cross Roller (XR) Taper Rollers	Precision crossed roller bearings (TXR) are designed to offer the highest levels of rotational accuracy and rigidity while conserving space and saving material costs. The bearing features two sets of races and rollers brought together at right angles with alternate rollers facing in opposite directions. This allows two half-rows of rollers to fit into the space of one. The steep-angle, tapered geometry results in a total effective bearing spread much greater than the width of the bearing itself. Able to withstand high overturning moments, the crossed roller bearing is ideal for the table bearing of machine tools, including vertical boring and grinding machines. It is uniquely suited to many other pivot and pedestal applications where space is limited or the lowest possible center of gravity of a rotating mass is required. Size range: ID 203.200 mm to 2463.800 mm (8.000 in. to 97.000 in.) OD 279.400 mm to 2819.400 mm (11.000 in. to 111.000 in.) Design Attributes: Provides benefits of two-row bearings in single-row space. Withstands high overturning moments. Combines the compactness of a single-row bearing with the stability of a two-row bearing. Applications: Vertical boring mills Vertical grinding machines Other machine tools
Precision Cylindrical Roller Bearings for Machine Tool	Our precision cylindrical roller bearings for screw drives feature a combination of axial cylindrical rollers and radial needle rollers. This unique configuration helps manage loads from multiple directions during highspeed operation. Several designs are available to accommodate varying screw drive designs. For applications where rotational accuracy, consistency and rigidity are critical, Timken has the solution – Timken® precision cylindrical roller bearings for rotary tables, indexing and vertical mill heads. Precision Cylindrical Roller Bearings for Rotary Tables We incorporate our engineering expertise into every product to enhance performance and productivity. Our precision cylindrical roller bearings for rotary tables are no exception. When rotational accuracy, consistency and rigidity in rotary tables are critical, Timken precision cylindrical roller bearings become the obvious solution. For applications where rotational accuracy, consistency and rigidity are critical, Timken has the solution – Timken® precision cylindrical roller bearings for rotary tables, indexing and vertical mill heads. Timken’s precision cylindrical roller bearings feature an integrated design that includes an L-shaped inner ring, shaft washer, outer ring, two thrust roller cage assemblies and a radial full complement row. The result? An easy-to-install unit that can manage loads from multiple directions. Superior running accuracy, lower operating temperature and reduced noise through P4 precision class. Product Details Greater load-carrying capacity and better bearing stiffness control, thanks to closely controlled preload Oil lubrication standard, with grease lubrication available Potential for increased axial stiffness with an optional thrust washer Bore sizes ranging from 80mm (3.149 in.) to 460mm (18.110 in)

Precision Tapered Roller

We produce Timken® precision tapered roller bearings in both inch and metric sizes to meet the full range of precision application requirements. They are engineered for superior accuracy and control – every time.

Precision Tapered Roller

Timken’s high-precision tapered roller bearings consist of carefully matched components that offer an added degree of fine-tuning in the bearing setting and adjustment procedure to maximize customer machine productivity. Timken manufactures high-speed designs with a variable preload capability for optimum performance. Timken also manufactures Precision Plus bearings – having an overall radial runout less than a single micron.

Landing Wheels

When a 500-ton airplane touches down on the runway, all the load is transmitted from the airframe to the ground through the landing wheels. Under these severe conditions, the wheels accelerate from  0 to 170+ MPH in less than a second and experience temperature ranges from sub-zero at 30,000 feet to the extreme heat at braking. At Timken we use our experience to make the best bearings for this application and help to make every landing a safe one.   The 629 performance code was created in cooperation with the leading wheel and brake manufacturers around the globe.   These wheel producers depend on Timken and our expertise to make each touch down a moment you can trust. Timken supports this business with dedicated engineering and a well trained service group that can assess problems and help you maximize your investment safely. Timken has leveraged this experience in bearings, the aerospace industry and maintenance best practices to create a standard for the whole industry, regardless of wheel manufacturer.  These maintenance standards are contained in the Aircraft Landing Wheel Bearing Maintenance Manual, a comprehensive end-user guide aimed at maintenance, repair and overhaul (MRO) operational staff. The manual addresses common landing wheel bearing procedures and issues. In addition, the manual covers removal, handling, cleaning, inspection, damage modes, maintenance and storage procedures. Timken also offers training on bearing maintenance and inspection.  Topics included are the Timken Best Practices for the following: Bearing Removal and Handling Bearing Cleaning and Inspection Bearing Damage Modes Bearing Lubrication Bearing Installation Bearing Storage Bearing Setting and Adjustment Included with the training is the new Timken Aircraft Landing Wheel Bearing Maintenance Manual outlining our 75+ years of experience with 629 performance code bearings.  Contact us to request more information about Timken’s training program. To order a copy of the manual, click here. Timken® tapered roller bearings for landing wheels meet the stringent performance demands of these aircraft wheels – whether in large commercial transports or small private airplanes. Timken marks these bearings with “20629” (inch) or “N0629” (metric), signifying that they are designated and manufactured for these applications. In most commercial applications, Timken holds Part Manufacturer Approval (PMA) from the FAA. Size Range: 1.375 in. to 10.5625 in. OD (0.500 in. to 9.125 in. cone bore) Design Attributes: Design meets both customer and FAA quality standards. Performance code 629 bearing enhancements are the standard configuration for current and new applications. These advanced bearings achieve superior performance through tightened tolerances and are able to accommodate the repeated spike loads of the weight of a jumbo jet during landing. Engineered surfaces are available to further improve wear, fatigue and frictional performance. Applications: Main and nose landing wheel assemblies for private, commercial and military aircraft Engineered Surfaces for Aircraft Bearings Timken Engineered Surfaces incorporated into aircraft landing wheels can solve rib/roller end scuffing common in aerospace applications.

Thin Section Ball

Timken® precision thin section bearings offer high accuracy in a low profile design, available in standard stainless or chrome steel, configured as deep groove or angular contact, and with a host of special features.

Thin Section Ball

Timken’s precision thin section bearing line offers high accuracy and low profile design in standard stainless steel or chrome steel configurations. This line includes deep groove and angular contact configurations with special features available to meet specific application requirements. Design Attributes: Precision tolerances – meet ABEC 5F (ISO P5) or ABEC 7F (ISO P4) for high running accuracy. Material selection – standard offerings include 440C stainless steel and 52100 chrome steel. Superfinished raceways – provide a smooth surface finish to reduce internal friction and vibration. High quality ball complement – grade 5 or better balls optimize smooth rolling performance. Retainers – various configurations and materials to meet performance needs. Applications: Precision robotic joints Semiconductor equipment and measuring systems Radar and microwave equipment Solar array panels Guidance systems Medical Imaging equipment