Angular contact ball bearings feature inclined raceway structure. Steel balls form a fixed contact angle with raceways to bear radial load and unidirectional axial load simultaneously. They must be combined via three pairing modes: back-to-back (DB), face-to-face (DF) and tandem (DT) to achieve bidirectional axial limitation. Boasting high limiting speed, strong axial rigidity and superior rotational accuracy, they are categorized by contact angles: 15°(C),25°(AC),40°(B). Small contact angles deliver high speed and low heat generation, while large contact angles provide heavy axial load capacity. Available in open type and rubber sealed dustproof type with multi-level precision (P0/P6/P5/P4). They serve as core supporting bearings for precision machine tool spindles, high-speed air compressors, high-speed gearboxes and precision pump bodies.

Main model classification:7000 ultra-thin high-speed series,7200 standard general series,7300 heavy-duty axial load series. Contact angle specifications:C(15°),AC(25°),B(40°). Pairing forms:DB back-to-back,DF face-to-face,DT tandem. Sealing:open type,2RS double-sided rubber seal. Precision grades:P0 general grade,P6 precision grade,P5 high-precision grade,P4 ultra-precision grade dedicated for spindles.

Performance comparison: Compared with deep groove ball bearings, axial load capacity is greatly enhanced to resist axial play, suitable for rotating shafts with large axial force. Compared with tapered roller bearings, it has overwhelming high-speed performance and lower operating temperature rise for high-speed precision scenarios. Compared with spherical roller bearings, rigidity and positioning accuracy are higher without self-aligning capability, requiring strict concentricity for shafts and housings. Shortcoming: cannot be used alone and must be installed in pairs with high requirements for assembly and commissioning; installation eccentricity will cause rapid bearing wear and scrapping.

CNC lathe spindles, machining center spindles, high-speed rotors of screw air compressors, high-speed gear increasing boxes, high-pressure circulating pumps and textile high-speed spindles rotate at high speed all year round under combined radial pressure and axial thrust load with strict indicators for spindle runout, axial float and operating temperature rise. Inferior angular contact ball bearings suffer from offset contact angle machining leading to unbalanced axial force after pairing and excessive spindle runout. Rough raceway grinding causes high-temperature howling noise at high speed. Insufficient steel purity triggers fatigue pitting on steel balls under high-speed alternating load. Lack of accurate pairing marks makes preload control impossible during on-site assembly, directly resulting in deviated machining accuracy of machine tools, high-temperature shutdown of air compressors, abnormal vibration of high-speed gearboxes and spindle seizure overhaul. Maintenance cost for precision equipment bearing failure is extremely high.

NMT angular contact ball bearings cover full specifications of 7000,7200 and 7300 series with sufficient stock of multiple contact angles, precision grades and pre-paired finished bearings marked for direct installation after delivery. Manufactured from high-purity electroslag remelting bearing steel with super mirror finishing on inner and outer ring raceways to precisely control contact angle tolerance for uniform axial force after pairing. P4/P5 high-precision bearings undergo dimension grouping and end face grinding for stable preload and ultra-small spindle rotational runout. 15° small contact angle fits high-speed machine tool spindles; 25° balances high speed and axial load for air compressor rotors; 40° large contact angle is used for axial positioning of heavy-duty gearboxes. Sealed versions adopt high-speed resistant fluoro-rubber oil seals to block lubricant splashing and dust intrusion. Open bearings adapt to thin oil lubrication for high-speed spindles including oil-air lubrication and oil injection lubrication. All dimensions comply with national standards for direct replacement of domestic and imported precision angular contact bearings for new machine assembly, spindle overhaul and air compressor maintenance.

Precision processing equipment, high-speed fluid equipment and high-speed transmission equipment are upgraded toward ultra-high rotational accuracy, long service life with low temperature rise, stable axial rigidity and low-precision commissioning demand. Ordinary low-grade angular contact ball bearings have large angle tolerance, non-standard pairing and poor raceway finish, leading to rapid attenuation of axial rigidity, sustained high temperature rise and poor durability of spindle accuracy during high-speed operation. They cannot meet the requirements of high-precision cutting of CNC machine tools, 24-hour high-speed operation of screw air compressors and stable transmission of speed increasing boxes. The market urgently needs angular contact ball bearings with precise pairing, accurate angles and high-speed wear resistance.

NMT implements strict control over contact angle forming accuracy. Pre-paired bearings have minimal dimensional error in the same group for excellent consistency of assembly preload. Mirror-finished raceways reduce high-speed friction heat to maintain stable temperature during long-term continuous high-speed operation. High-purity bearing steel delays fatigue spalling to extend service life of precision components. All finished bearings pass runout inspection, temperature rise test and pairing verification to eliminate defective products with angle deviation, dimensional mismatch and surface defects, ensuring positioning accuracy of precision spindles and restraining overheating and vibration of high-speed equipment.

Core Product Advantages

Inclined raceway contact angle design bears radial and unidirectional axial loads simultaneously; paired installation realizes bidirectional axial locking and limiting.

Three optional contact angles: small angle for high speed & low heat generation, large angle for strong axial bearing capacity to match working conditions accurately.

Factory pre-paired finished bearings (DB/DF/DT) with identification marks for direct installation, omitting on-site selection and commissioning procedures.

Optional P4 ultra-precision spindle-grade precision for excellent control of spindle end face and radial runout to guarantee machining accuracy.

Dual structure of open type and sealed type: open type for high-speed oil-air lubrication, sealed type for grease lubrication with dustproof and waterproof performance.

Super-finished raceways reduce friction loss during high-speed rotation for controllable temperature rise during long continuous operation.

High-purity bearing steel resists fatigue wear under alternating load for long-term continuous high-speed operation.

Standard overall dimensions allow replacement for precision equipment maintenance without modification of shaft seats for strong versatility.

Typical Application Scenarios

Precision support bearings for spindles of vertical machining centers, CNC lathes, grinders and boring machines; high-speed rotor bearings for screw air compressors and scroll air compressors; high-speed output shaft bearings for high-speed gearboxes, speed increasers and reducers; spindle bearings for high-pressure oil pumps, booster water pumps and refrigerant compressors; high-speed rotating shaft bearings for textile spinning spindles and chemical fiber texturing machines; spindle bearings for precision detectors, high-speed centrifuges and laboratory rotating equipment.

Quality Assurance

NMT angular contact ball bearings are made of vacuum refined bearing steel to reduce internal inclusions and improve high-speed fatigue resistance. Super-finished raceways greatly reduce surface roughness and frictional heat generation. Precision-grade bearings pass dynamic and static balance calibration for operation above 10000rpm. Compatible with high-speed extreme pressure grease, oil-air lubrication and circulating thin oil lubrication, operating temperature ranges from -35℃ to 130℃, suitable for precision dust-free workshops, high-temperature cavities of air compressors and sealed high-speed transmission boxes.

Product Range

7000 ultra-thin high-speed series,7200 standard main series,7300 heavy-duty axial series; Contact angles:C(15°),AC(25°),B(40°); Pairing modes:DB back-to-back,DF face-to-face,DT tandem; Sealing:OPEN open type,2RS double-sided rubber seal; Precision grades:P0,P6,P5,P4 ultra-precision grade.

Brand Strength

NMT Japan solves three common defects of ordinary angular contact ball bearings: unbalanced pairing caused by poor contact angle accuracy, excessive temperature rise at high speed and poor retention of precision spindle accuracy. Three core technologies including precise contact angle forming, factory pre-pairing and mirror super-finishing of raceways deliver high axial rigidity, low temperature rise at high speed and stable high-precision output. We supply bearings for machine tool manufacturers, air compressor OEMs, high-speed gearbox enterprises and precision equipment maintenance service providers to stabilize machining accuracy of precision spindles, reduce shutdown frequency caused by high-temperature faults of high-speed equipment and cut overhaul costs of high-end equipment spindles.