1 Complete Model & Code Explanation

Model: S71901 CDGA/HCP4A

Code Definition

S71901: Basic dimension specification of 719 extra-light single-row angular contact ball bearing, S denotes stainless steel material

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

GA: Double-sided contact rubber seal structure. Elastic lip closely fits the outer ring surface, resisting dust, water mist and mild liquid splash; pre-filled water-resistant long-life grease at factory

HCP4A: Upgraded ISO P4A high precision tolerance grade, stable 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: GA contact seal provides superior protection compared with GB non-contact seal, blocking water mist and slight cutting fluid splash. However, it cannot endure long-term liquid immersion and is not suitable for heavy corrosion or continuous liquid flushing. Stainless steel performs better in rust prevention than bearing steel, but fails to resist salt water, strong acid and alkali. Built-in water-resistant grease has limited service life. Continuous high-speed operation accelerates grease deterioration; regular replenishment maintenance is recommended.

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: GA double-sided contact rubber seal

Base material: High-hardness martensitic stainless steel

Surface coating: Uncoated

Pre-installed lubricant: Water-resistant long-life 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: HCP4A (upgraded ISO high precision grade)

Basic dynamic load rating: 2.48 kN

Basic static load rating: 1.16 kN

Speed reference: Contact manufacturer for attainable rotational speed data

Net weight: 0.0102 kg

Indicative carbon footprint: 0.037 kg CO₂e

eClass code: 23-05-08-04

UNSPSC code: 31171531

Suffix Comparison within Series

S71901 CDGA/HCP4A: Martensitic stainless steel, 30° contact angle, double contact rubber seal, water-resistant grease, HCP4A high precision, duplex capable (this model)

S71901 CDGB/HCP4A: Stainless steel double non-contact dust seal, lower friction and higher limiting speed, only for dry low-condensation environment

S71901 ACDGA/HCP4A: Stainless steel contact sealed bearing with 25° contact angle focusing on higher limiting speed

71901 CDGB/P4A: Ordinary bearing steel non-contact sealed model without rust resistance, limited to dry environment

S71901 CDGQ/HCP4A: Factory pre-matched duplex contact sealed stainless steel bearing set

2 Structure & Operating Characteristics

Japan NMT S71901 CDGA/HCP4A adopts proven ultra-thin extra-light 719 series structure. CD 30° contact angle raceway evenly bears radial load and axial thrust and delivers sufficient axial rigidity for miniature precision rotary shafts. Inner and outer rings are manufactured from high-hardness martensitic stainless steel with dedicated stabilized heat treatment. Raceways are ultra-precision mirror ground to suppress vibration and noise during high-speed rotation while offering basic anti-condensation and anti-rust performance.

GA double-sided contact rubber seal features elastic lip closely attached outside the raceway to form complete sealing barrier. Compared with non-contact seal, it effectively blocks water mist, floating dust and mild cutting fluid splash. Special hydrolysis-resistant grease is pre-sealed at factory and resists emulsification under humid conditions.

Bearings are delivered as single units without factory duplex grinding. Customers configure different duplex layouts with precision spacers according to equipment rigidity. Owing to continuous friction of contact lip, limiting rotational speed is slightly lower than stainless steel bearings with non-contact seal of identical size. The load rating of stainless steel material is marginally lower than bearing steel, so load conditions should be verified during selection. The seal only copes with intermittent liquid splash; extra housing protection is required under continuous water immersion, salt spray and heavy corrosion.

3 Core Performance Advantages

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

2. GA double-sided contact rubber seal: Complete sealing barrier, effectively blocking dust, water mist and mild cutting fluid splash for wider environmental adaptability.

3. Martensitic stainless steel substrate: Anti-rust and anti-condensation capability, solving rusting problems of ordinary bearing steel.

4. Factory pre-filled hydrolysis-resistant long-life grease: Hard to emulsify under humid conditions and extends service cycle in moist environment.

5. HCP4A upgraded high precision grade: Minimal rotary runout, satisfying high-precision positioning requirements of precision inspection equipment and miniature spindles.

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

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Assembly of HCP4A high precision stainless steel 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 squeezing or scratching rubber seal lips during assembly. Damaged lips will lead to immediate loss of waterproof and dustproof performance. 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 contact sealed single bearing

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

Selection reference:

Condensation, water mist and intermittent cutting fluid splash present, rust prevention and reliable sealing required → S71901 CDGA/HCP4A (this model);

Humid environment, higher limiting speed needed, only dry dust without liquid splash → S71901 CDGB/HCP4A non-contact seal version;

Predominantly radial load, priority to raise limiting speed → S71901 ACDGA/HCP4A;

Mass standardized equipment without on-site preload adjustment → factory matched set S71901 CDGQ/HCP4A;

Fully dry and dust-free environment, higher load capacity pursued → bearing steel model 71901 CDGB/P4A.

5.3 Lubrication Scheme

S71901 CDGA/HCP4A is pre-filled with hydrolysis-resistant grease suitable for conventional working conditions with water vapor. Auxiliary micro oil supply for cooling is recommended under continuous operation near maximum limiting speed to slow grease aging and emulsification. Compatible water-resistant grease must be used for replenishment during maintenance. Mixing different grease types is prohibited to avoid chemical reaction and grease failure.

5.4 Environmental Application Notes

GA contact rubber seal resists water mist and intermittent trace liquid splash, but cannot sustain long-term water immersion or continuous erosion by salt water, acid and alkali corrosive media. Auxiliary housing sealing rings should be installed where continuous liquid flushing and heavy salt spray exist. Stainless steel only provides basic rust resistance and cannot be treated as fully corrosion-resistant material. Ventilated and dry environment is suggested for long-term shutdown storage to reduce condensation.

6 Daily Maintenance & Fault Troubleshooting

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

Pre-filled water-resistant grease has fixed service life. Carry out grease replenishment or bearing replacement once maintenance cycle is reached during long continuous operation. Common failure triggers: water intrusion caused by scratched seal lip leading to grease emulsification, persistent overheating from excessive preload, abrasive wear due to dust ingress, slight rust under prolonged high humidity environment, grease hydrolysis failure.

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