Angular contact ball bearings adopt an inclined contact structure between steel balls and raceways with fixed contact angles, capable of bearing combined radial load and unidirectional axial load. Three matching configurations (DB back-to-back, DF face-to-face, DT tandem) realize bidirectional axial limit and overall rigidity reinforcement, adapting to precision working conditions with high-speed rotation and axial preload. Products are divided into open non-sealed type and rubber-sealed type. Cages include phenolic resin high-speed cages, brass solid cages and steel stamped cages. Three main contact angle specifications are available: 15° (C ultra-high speed), 25° (AC general high speed), 40° (B heavy axial load). They serve as core support bearings for CNC machining centers, lathe spindles, high-speed grinding machines, screw air compressors and precision reducers, integrating high precision, high rotating speed and high rigidity.

Main model classification: 7000 ultra-thin light precision series, 7200 standard main series, 7300 heavy-duty large contact angle series. Contact angle types: C 15° small contact angle high-speed type, AC 25° balanced type, B 40° heavy axial load type. Sealing structures: OPEN open type, 2RS double-sided rubber seal. Precision grades: P0 general transmission, P6 precision transmission, P5 machine tool precision, P4 spindle ultra-precision, P2 instrument grade. Clearance groups: C0 normal, C3 increased clearance. Matching forms: DF face-to-face, DB back-to-back, DT tandem finished bearings.

Performance comparison: Compared with deep groove ball bearings, axial load capacity is doubled, and bidirectional axial positioning is realized via matching for stronger spindle rigidity, yet single bearing cannot bear bidirectional axial force and must be used in pairs. Compared with tapered roller bearings, the limiting speed is greatly improved with lower friction resistance and temperature rise, suitable for high-speed precision spindles, while heavy impact resistance is weak. Compared with cylindrical roller bearings, it has both radial and axial load capacity with excellent spindle positioning accuracy, but cost performance is insufficient for pure radial heavy-load scenarios. Shortcoming: A single bearing only bears unilateral axial force, prone to axial play when used alone; high requirements for matching assembly, and assembly errors easily cause overheating seizure.

Spindles of vertical machining centers, CNC lathe motor spindles, high-speed cylindrical grinders, screw air compressor rotors, precision gearboxes and high-speed vacuum pumps operate continuously under high-speed rotation, alternating impact of axial cutting force, high spindle preload and constant-temperature oil cooling lubrication. Inferior angular contact ball bearings have rough grinding textures on raceways causing high-frequency vibration and noise at high speed. Deviated contact angles lead to unbalanced stress after pairing and excessive spindle runout. Insufficient heat resistance of resin cages causes cracking and fragmentation under high-speed centrifugal high temperature. Unqualified bearing end face parallelism results in uneven preload stress and local overload ablation after pairing, directly leading to excessive spindle roundness error of machine tools, unqualified workpiece finish, abnormal high-temperature noise of air compressors and major overhaul due to spindle bearing seizure. The maintenance cost and shutdown loss of precision equipment are extremely high.

NMT angular contact ball bearings cover full specifications of 70, 72 and 73 series with sufficient stock for C/AC/B contact angles and regular supply of P4 and P5 machine tool precision grades. DF/DB/DT pre-matched finished bearings can be installed directly. Manufactured from vacuum-degassed high-purity bearing steel, inner and outer ring raceways undergo ultra-precision mirror grinding with strict control of contact angle forming accuracy to ensure uniform load distribution after pairing. High-speed models are equipped with polyimide resin cages featuring light weight, low wind resistance and high temperature resistance for tens of thousands of revolutions high-speed spindles. Heavy-load models adopt brass solid cages for shear impact resistance. Sealed versions use fluororubber seals to resist corrosion from high-speed lubricating grease and oil temperature aging. All dimensions comply with national precision dimensional tolerances for replacement of imported bearings for maintenance of machine tool spindles, air compressors and precision gearboxes without reworking shaft diameters and bearing housings.

High-end CNC machine tools, high-speed power equipment and precision fluid equipment are upgraded toward high spindle rigidity & low runout, low temperature rise at high speed, long-term dimensional stability and no on-site matching & commissioning. Ordinary low-grade angular contact ball bearings suffer from out-of-control angle accuracy, poor end face flatness and insufficient cage heat resistance, resulting in rigidity attenuation, increased runout and excessive temperature rise after short-term high-speed spindle operation, failing to meet the demands of continuous high-precision cutting of CNC finishing and long-term high-speed operation of air compressors. The market urgently needs precision angular contact ball bearings with precise pre-matching, accurate angles and high-speed heat resistance.

NMT achieves high-speed low vibration, stable axial rigidity and balanced preload stress via three core processes: ultra-precision mirror processing of raceways, precise contact angle shaping and finished product pre-matching inspection. All finished bearings pass end face parallelism test, contact angle verification, high-speed temperature rise simulation test and matching combination verification to eliminate defective products with angle deviation, poor flatness and raceway defects. It stabilizes spindle rotation accuracy, controls high-speed temperature rise and extends the trouble-free service life of precision equipment.

Core Product Advantages

Inclined angle contact structure bears combined radial & unidirectional axial load; three matching modes realize bidirectional axial fixation for greatly enhanced spindle rigidity.

Optional multiple contact angles: 15° for ultra-high-speed motor spindles, 25° balancing rotating speed and axial force, 40° for heavy axial thrust conditions.

P4/P5 high-precision grades with strict control of end face parallelism, finished pre-matching for direct on-site assembly to eliminate manual grinding processes.

Special high-speed resin cage with low wind resistance and light weight reduces oil stirring heat at high speed for high-speed motor spindle applications.

Brass solid cage version delivers impact resistance and alternating load resistance for heavy-duty transmission scenarios such as air compressors and reducers.

Optional double-sided rubber seal blocks intrusion of cutting fluid, oil and impurities into raceways for machine tool oil injection cooling environments.

Precisely controlled dimensional tolerances enable zero grinding replacement of imported precision bearings for one-time compliance of spindle assembly accuracy.

Factory pre-matching verification ensures uniform axial preload to avoid early burnout failure caused by concentrated local stress.

Typical Application Scenarios

Support bearings for spindles of vertical/horizontal machining centers, CNC lathe motor spindles and turn-mill composite machine tools; grinding wheel spindle bearings for high-speed cylindrical grinders, internal grinders and face grinders; high-speed rotor bearings for screw air compressors and scroll air compressors; high-speed output shaft bearings for precision planetary reducers and gearboxes; rotor bearings for high-speed vacuum pumps and turbo fans; precision positioning bearings for high-speed printing rollers and textile high-speed spindles.

Quality Assurance

NMT angular contact ball bearings are made of vacuum remelted bearing steel to reduce internal inclusions and improve contact fatigue life. Ultra-precision mirror finishing of raceways reduces friction coefficient for gentle and stable temperature rise at high speed. High-speed cages withstand temperatures up to 180℃, and seals resist corrosion from cutting fluid and synthetic lubricating oil. Compatible with high-speed grease, oil-air lubrication and circulating thin oil lubrication, operating temperature ranges from -35℃ to 160℃, adapting to high-speed oil-air cooling of machine tools, high-temperature cavities of air compressors and sealed lubrication of precision reducers.

Product Range

7000 ultra-thin precision series, 7200 standard balanced series, 7300 heavy axial load series; Contact angles: C15° high-speed type, AC25° general type, B40° heavy-duty type; Sealing: open type, 2RS double-sided seal; Precision grades: P0, P6, P5, P4, P2; Matching styles: DF face-to-face, DB back-to-back, DT tandem matched assemblies.

Brand Strength

NMT Japan solves three major pain points of ordinary angular contact ball bearings: large spindle runout caused by poor matching accuracy, high-temperature damage of high-speed cages and unbalanced stress from contact angle deviation. Core technologies including ultra-precision raceway machining, accurate contact angle forming and factory finished pre-matching deliver spindle-specific angular contact ball bearings with high rigidity, stable high-speed performance and high precision. We supply bearings for machine tool spindle manufacturers, air compressor OEMs, precision reducer manufacturers and CNC equipment maintenance service providers to stabilize machining accuracy of precision machine tools, control temperature rise of high-speed power equipment and reduce major overhaul frequency and shutdown loss of high-end equipment.