1 Complete Model & Code Explanation

Model: 71901 CDGB/P4A

Code Definition

71901: Basic dimension specification of 719 extra-light single-row angular contact ball bearing

CD: Standard raceway geometry with 30° nominal contact angle, outstanding axial load capacity for combined radial and axial loads with heavy axial thrust

GB: Double-sided non-contact dust seal structure with metal retaining lip; pre-filled long-life high-speed grease supplied from factory

P4A: ISO P4A high precision tolerance grade, excellent rotary accuracy, single unit supports on-site DB/DF/DT free duplex assembly

Supply form: Separate single bearing without factory duplex lapping. Precision spacers are required for preload adjustment when two bearings are combined.

Important reminder: GB non-contact seals only provide light dust protection and cannot block coolant, water mist, cutting debris or heavy dust. Not suitable for humid or corrosive environments; stainless steel series is recommended for condensation conditions. Built-in grease has limited service life. Auxiliary external lubrication and cooling are suggested under continuous extreme high-speed operation. Bearing steel material offers no rust resistance; dry storage protection is required for long standby periods.

Basic Parameters

Bore d: 12 mm

Outer diameter D: 24 mm

Width B: 6 mm

Nominal contact angle: 30°

Structure: Single-row angular contact ball bearing, supplied as single unit

Internal geometry: CD raceway with 30° contact angle

Contact type: Two-point contact

Number of rows: Single row

Ring construction: Integrated inner ring, integrated outer ring

Seal arrangement: GB double-sided non-contact dust seal

Base material: High-purity bearing steel

Surface coating: Uncoated

Pre-installed lubricant: High-speed long-life spindle grease (pre-filled at factory)

Duplex capability: Universal matchable single bearing, supporting DB back-to-back / DF face-to-face / DT tandem layout; preload adjusted on site

Precision class: P4A (ISO high precision grade)

Basic dynamic load rating: 2.72 kN

Basic static load rating: 1.31 kN

Speed reference: Contact manufacturer for attainable rotational speed data

Net weight: 0.0105 kg

Indicative carbon footprint: 0.039 kg CO₂e

eClass code: 23-05-08-04

UNSPSC code: 31171531

Suffix Comparison within Series

71901 CDGB/P4A: Bearing steel, 30° contact angle, double non-contact seal, pre-filled grease, P4A high precision, duplex capable (this model)

71901 CD/P4A: Open non-sealed bearing steel version, no pre-filled grease, designed for continuous oil-air lubrication

71901 ACDGB/P4A: Bearing steel sealed high-speed bearing with 25° contact angle focusing on higher limiting speed

71901 CDGQ/P4A: Factory pre-matched duplex sealed bearing set made of bearing steel

S71901 CDB/HCP4A: Martensitic stainless steel sealed variant with basic condensation and rust resistance

2 Structure & Operating Characteristics

Japan NMT 71901 CDGB/P4A adopts the proven ultra-thin extra-light 719 series structure. CD 30° contact angle raceway design distributes radial load and axial thrust evenly and provides sufficient axial rigidity for various miniature precision high-speed rotary shafts. Inner and outer rings are manufactured from high-purity bearing steel with stabilized heat treatment, and raceways are finished with ultra-precision mirror grinding to suppress vibration and noise during high-speed rotation.

GB double-sided non-contact dust protection relies on clearance retaining lips without continuous contact friction between seal and ring. It achieves higher limiting speed compared with contacting seals. Special high-speed grease is pre-sealed at factory. Complex external lubrication circuit can be omitted under standard working conditions, simplifying mechanical design for compact integrated modules.

Bearings are delivered as single units without factory duplex grinding. Customers can configure different duplex layouts with spacers according to spindle rigidity requirements. Bearing steel delivers superior load capacity versus stainless steel counterparts but does not resist rust. Seals can only block dry floating dust; water vapor and cutting fluid will penetrate easily, so additional housing protection must be installed in harsh operating conditions.

3 Core Performance Advantages

1. CD 30° contact angle geometry: Excellent axial load capacity for combined loads dominated by axial thrust.

2. GB double-sided non-contact dust seal: Low friction loss, balancing light dust protection and high rotational speed.

3. Factory pre-filled high-speed grease: No complicated external lubrication system required for standard operation, simplified equipment design.

4. P4A ISO high precision grade: Low rotary runout, satisfying positioning requirements of precision inspection equipment and miniature machining spindles.

5. Flexible free duplex assembly: Single bearing supports DB/DF/DT layouts for diversified spindle rigidity schemes.

6. High-purity bearing steel substrate: Superior load rating; mirror-finished raceway ensures smooth rotation and extended service life.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Assembly of P4A precision bearings is recommended in constant-temperature dust-free workshops. Thermal mounting is preferred; direct impact on bearing rings and rolling elements is strictly forbidden. Avoid collision with seal lips during assembly, which may deform clearance and weaken dust resistance. When two bearings operate as one set, select precision spacers of equivalent accuracy and adjust target preload via load measurement to ensure balanced load sharing and prevent abnormal vibration and temperature rise at high speed.

5.2 Duplex Layout & Selection Guidance

Supply condition: Independent sealed single bearing

Available assembly layout: DB back-to-back / DF face-to-face / DT tandem

Selection reference:

Dry low-dust environment, external circulating lubrication difficult to arrange, simple maintenance required → 71901 CDGB/P4A (this model);

Continuous operation near maximum limiting speed with oil-air lubrication system → open type 71901 CD/P4A;

Predominantly radial load, priority to raise limiting speed → 71901 ACDGB/P4A;

Mass standardized equipment without on-site preload adjustment → factory matched set 71901 CDGQ/P4A;

Condensation and moisture present, basic anti-rust performance needed → stainless steel sealed bearing S71901 CDB/HCP4A.

5.3 Lubrication Scheme

71901 CDGB/P4A is pre-filled with high-speed spindle grease. Medium and low-speed continuous operation can rely on original grease for long-term service. Auxiliary external oil injection or oil-air cooling lubrication is recommended if operating continuously near maximum speed to slow grease degradation. Mixing incompatible grease and oil is prohibited. Use equivalent high-speed grease for replenishment during maintenance.

5.4 Environmental Application Notes

GB non-contact seals only defend against fine dry floating dust. Water mist, cutting fluid, oil contamination and hard debris can penetrate the raceway easily. Direct use is not advised under humid conditions or locations with liquid splash; auxiliary housing sealing must be installed. Bearing steel cannot resist rust. Dry environment or anti-rust preservation is necessary for long-term shutdown storage.

6 Daily Maintenance & Fault Troubleshooting

Implement low-speed staged running-in after assembly, continuously monitor bearing temperature and vibration, and increase rotational speed step by step after stable operation. Regularly inspect abnormal noise and temperature rise to predict grease aging cycle.

Pre-filled grease has a fixed service life. Grease replenishment or bearing replacement should be carried out once maintenance cycle is reached under long continuous high-speed operation. Common failure triggers: abrasive wear caused by hard particle intrusion, persistent overheating from excessive preload, seal deformation leading to dust ingress, grease carbonization under high temperature, raceway rust induced by humid atmosphere.

Arrange periodic inspection to detect rising vibration, abnormal noise and excessive temperature early, avoiding bearing seizure and rapid precision degradation.