Angular contact ball bearings adopt inclined raceway structure. Steel balls form a fixed contact angle with inner and outer rings, which can bear radial load and unidirectional axial load simultaneously. Three paired mounting modes (back-to-back DB, face-to-face DF, tandem DT) realize bidirectional axial limit and high-rigidity support. Preload force can be applied via gaskets and nuts to eliminate internal clearance, greatly improving spindle rotational rigidity, rotation accuracy and anti-overturning capacity. Products are divided into three contact angle specifications: 15°(C), 25°(AC), 40°(B). Smaller contact angle delivers higher limiting speed, while larger contact angle offers stronger axial load capacity. Structural types include open type, double-sided dust-proof seal and double-sided rubber seal. Cages are made of bakelite, nylon and solid brass. As core bearings for CNC machining center spindles, cylindrical grinders, ball screw fixed ends, high-speed centrifugal equipment and industrial robot joints, they feature outstanding advantages of precision rotation, high-rigidity preload, stable high-speed operation and axial impact resistance.

Main model classification: 7000 ultra-light high-speed series, 7200 standard main series, 7300 large-angle heavy-duty series; Contact angle types: C15° high-speed type, AC25° balanced type, B40° heavy axial load type; Pairing forms: DB back-to-back, DF face-to-face, DT tandem; Precision grades: P0 general grade, P6 transmission grade, P5 precision grade, P4/P2 ultra-precision machine tool grade; Clearance: standard clearance, small clearance for preload.

Performance comparison: Compared with deep groove ball bearings, axial load capacity is multiplied. Combined preload restrains axial play for precise spindle runout control, yet paired installation is mandatory for bidirectional axial load resistance. Compared with tapered roller bearings, the limiting speed is several times higher with lower frictional heat generation, suitable for high-speed precision spindles but slightly inferior in heavy-load rigidity. Compared with cylindrical roller bearings, it has axial positioning capability for ball screw axial locking while weaker in radial load capacity. Shortcoming: Single bearing only bears unidirectional axial force and suffers axial play when used alone. Stringent requirements for pairing accuracy and preload torque during installation; improper assembly easily leads to overheating seizure.

CNC machining centers, precision grinders, high-speed ball screw drives and robot joints operate under long-term high-speed spindle cutting, alternating axial impact, precision positioning, high-speed heat generation and intrusion of cutting fluid mist. Inferior angular contact ball bearings suffer from uneven preload and high-speed vibration caused by deviation of raceway contact angle. Insufficient precision of steel balls leads to excessive spindle circular runout and poor machining texture of workpieces. Loose bakelite cages crack and jam under high centrifugal force at high speed. Poor cutting fluid resistance of seals allows emulsion intrusion and raceway rusting, directly resulting in spindle chatter marks, scrapped workpieces due to machining accuracy failure, enlarged screw clearance & positioning error, robot joint jamming & abnormal noise, and shutdown of high-speed equipment due to excessive temperature rise. Precision machine tools face high maintenance costs and sharp drop in production yield.

NMT angular contact ball bearings cover full sizes and contact angles of 7000/7200/7300 series, with sufficient stock for P4/P2 ultra-precision spindle bearings, paired ball screw bearings and cutting-fluid-resistant sealed bearings. Manufactured from ESR high-purity bearing steel, inner and outer ring raceways are processed by ultra-precision grinder for angle forming grinding with tight control on contact angle tolerance to ensure uniform load distribution after pairing. Grade G3/G5 precision steel balls are selected by grading to realize ultra-small rotational runout for high-precision cutting. Solid bakelite cages adapt to high-temperature high-speed conditions of machine tool spindles, nylon cages serve low-noise high-speed transmission, and brass cages are applied for high-temperature heavy-load equipment. Sealed versions adopt fluororubber sealing rings resistant to emulsion to block intrusion of cutting fluid and dust. Pre-paired finished bearings (DB/DF/DT) are available ex-factory to omit on-site gasket grinding procedures. All dimensions comply with national general standards for direct replacement of old bearings on machine tool spindles and ball screws without modification of spindle boxes.

CNC machine tools, precision grinding equipment, high-speed transmission mechanisms and multi-joint robots are upgraded toward ultra-high rotation accuracy, low heat generation at high speed, long-term accuracy retention and pre-assembled pairing-free installation. Low-grade angular contact ball bearings with large contact angle error, poor steel ball precision and insufficient heat resistance of cages suffer from rapid accuracy attenuation, severe heat generation and bearing fracture after short spindle operation, failing to guarantee dimensional tolerance for precision machining. The market urgently needs precision paired angular contact ball bearings with precise raceway angle grinding, high-precision steel balls and working-condition-adaptive cages.

NMT achieves high-rigidity low-runout spindle performance, low temperature rise at high speed and stable axial load bearing via three core processes: precision angle forming grinding of raceways, sorting & pairing of high-precision steel balls and pre-paired finished assembly. Finished bearings pass contact angle inspection, spindle rotational runout test, high-speed temperature rise durability test and preload pairing verification to eliminate defective products with angle deviation, steel ball flaws and cage defects. It ensures long-term stable accuracy of precision equipment and cuts comprehensive production costs including precision rework, tool wear and scrapped workpieces.

Core Product Advantages

Multiple contact angles for selection: 15° for high-speed spindles, 25° for balanced radial & axial load, 40° for ball screws with large axial load to match diverse working conditions flexibly.

Three pairing combinations available: back-to-back DB delivers strong anti-overturning moment, face-to-face DF features easy installation, tandem DT adapts to ultra-large axial tension.

Axial preload can be applied to eliminate clearance for greatly improved spindle rigidity, strong anti-vibration cutting performance and higher surface finish of workpieces.

Ultra-precision P4/P2 bearings realize ultra-small spindle end & radial runout to meet finish machining demands of grinders and 5-axis machining centers.

Specialized cage options: bakelite cage resists high temperature & high speed without deformation, nylon cage for low noise, brass cage for continuous high temperature resistance.

Fluororubber sealed models resist corrosion from machine tool cutting fluid and emulsion to avoid raceway rust failure.

Pre-paired bearings delivered ex-factory enable direct on-site assembly, reducing working hours for technicians to grind gaskets and shortening machine tool overhaul cycle.

Standardized mounting dimensions ensure strong compatibility with mainstream machine tool spindles and ball screw bearings for simple spare parts stocking.

Typical Application Scenarios

Front & rear support bearings for vertical/horizontal machining centers and gantry machining centers; High-speed spindle bearings for internal & external cylindrical grinders and surface grinders; Paired positioning bearings for fixed ends and support ends of ball screws; Main shaft bearings for high-speed centrifugal air compressors and turbo fans; Rotary bearings for 6-axis industrial robots and collaborative robot joints; High-speed spindle bearings for CNC lathe motor spindles and engraving machines; High-speed output shaft bearings for precision gearboxes.

Quality Assurance

NMT angular contact ball bearings adopt carburizing integral quenched bearing steel with uniform hard wear-resistant raceways and high consistency of contact angle for balanced load after pairing. Compatible with high-speed spindle grease, oil-air lubrication and circulating oil lubrication, operating temperature ranges from -30℃ to 130℃, adapting to complex working conditions such as high-temperature spindles for CNC cutting, grinding mist environment, high-speed turbo equipment and continuous swing operation of robots.

Product Range

7000 ultra-thin high-speed series, 7200 standard general series, 7300 large-angle heavy-duty series; Contact angles: C15°, AC25°, B40°; Pairing modes: DB back-to-back, DF face-to-face, DT tandem; Precision grades: P0, P6, P5, P4, P2; Sealing: open type, double-sided dust cover, double-sided fluororubber seal; Cages: solid bakelite, nylon, solid brass.

Brand Strength

NMT Japan solves three major pain points of ordinary angular contact ball bearings: spindle vibration caused by uneven pairing angles, high-speed cage breakage and accuracy failure from rust due to cutting fluid ingress. Core technologies including precise raceway angle grinding, high-precision steel ball selection and complete pre-paired assembly develop precision angular contact ball bearings specially for machine tool spindles and ball screws. We supply bearings for complete machine tool manufacturers, spindle manufacturers, ball screw suppliers, robot enterprises and high-speed turbo equipment manufacturers to stabilize equipment machining accuracy, extend spindle accuracy life and reduce operation & maintenance costs as well as workpiece scrapping costs of precision equipment.