1 Complete Model & Code Explanation

Model: S71901 CDGA/P4A

Code Definition

S: Stainless steel version, martensitic stainless steel for enhanced rust resistance

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

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

GA: Double contact rubber seal. Sealing lips fit tightly to block dust and mist with basic protection performance

P4A: Upgraded ISO P4 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: S71901 CDGA/P4A stainless steel bearing delivers better anti-rust performance than standard bearing steel variant, suitable for condensation and mist conditions. It cannot endure long-term immersion in salt water or exposure to strong acid & alkali. Contact seals cause friction loss, so limiting speed is lower than open stainless steel bearing S71901 CD/P4A. Pre-filled high-speed grease for grease lubrication; long-term circulating oil lubrication is not recommended. The load capacity of stainless steel material is slightly lower than bearing steel 71901 CDGA/P4A of identical size.

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 contact rubber seal

Base material: Martensitic stainless steel

Surface coating: Uncoated

Pre-installed lubricant: Factory pre-filled high-speed bearing grease

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 (upgraded ISO high precision grade)

Basic dynamic load rating: 2.41 kN

Basic static load rating: 1.18 kN

Speed reference: Contact manufacturer for attainable rotational speed data

Net weight: 0.0112 kg

Indicative carbon footprint: 0.034 kg CO₂e

eClass code: 23-05-08-04

UNSPSC code: 31171531

Suffix Comparison within Series

S71901 CDGA/P4A: Martensitic stainless steel, 30° contact angle, double contact seal, pre-filled grease, P4A high precision, duplex capable (this model)

S71901 CDGB/P4A: Stainless steel double non-contact dust seal, lower friction and higher limiting speed, suitable for humid environment without heavy liquid splash

S71901 CD/P4A: Open non-sealed stainless steel bearing, no pre-filled grease, maximum limiting speed for circulating oil lubrication

S71901 ACDGA/P4A: Stainless steel double contact seal bearing with 25° contact angle optimized for rotational speed

71901 CDGA/P4A: Bearing steel version with higher load capacity, no anti-corrosion advantage for dry machining environment

2 Structure & Operating Characteristics

Japan NMT S71901 CDGA/P4A adopts proven ultra-thin extra-light 719 series structure. CD 30° contact angle raceway evenly bears radial load and axial thrust and provides sufficient axial rigidity for miniature precision rotary spindles. Inner and outer rings are forged from martensitic stainless steel to resist rust induced by vapor and condensation. Raceways are ultra-precision mirror ground to suppress vibration and noise during high-speed rotation.

Equipped with GA double contact rubber seals, sealing lips closely attach to ring end faces. It achieves superior protection against dust and cutting fluid mist compared with non-contact seals, adapting to working conditions with cutting fluid splash and high humidity condensation. High-speed grease is pre-filled at factory; continuous grease lubrication can be maintained without external oil supply under normal conditions.

Bearings are delivered as single units without factory duplex grinding. Customers arrange various duplex layouts with precision spacers according to machine structure. Friction generated by contact seals leads to higher temperature rise at high speed compared with open stainless steel bearings, so rated speed needs to be evaluated during model selection. Seals only offer basic protection and cannot resist continuous salt spray or long-term chemical erosion.

3 Core Performance Advantages

1. S stainless steel substrate: Martensitic stainless steel effectively prevents rust caused by condensation and mist, solving rust problems of ordinary bearing steel in high-humidity environment.

2. CD 30° contact angle geometry: Outstanding axial load capacity for combined loads with obvious axial thrust.

3. GA double contact seal: Superior dust and mist resistance, suitable for lightly polluted and high-humidity working environment.

4. Factory pre-filled high-speed grease: Supports independent grease lubrication without complicated circulating oil system.

5. P4A upgraded high precision grade: Minimal rotary runout, meeting high-precision positioning requirements of rotary shafts and small spindles.

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

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Assembly of P4A high precision stainless steel bearings is recommended in constant-temperature dust-free clean workshops. Thermal mounting is preferred; direct impact on bearing rings, rolling elements and sealing components is strictly forbidden. Dust protection must be implemented throughout assembly. Scratches on sealing lips by foreign impurities will greatly weaken mist-proof and anti-rust performance. When two bearings work as a set, select precision spacers of matching accuracy and adjust target preload via load measurement to ensure balanced load sharing, avoid high-speed vibration, abnormal temperature rise and local overheating aging of sealing lips.

5.2 Duplex Layout & Selection Guidance

Supply condition: Independent single contact sealed stainless steel bearing

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

Selection reference:

High humidity, condensation and mist environment, grease lubrication, anti-rust required → S71901 CDGA/P4A (this model);

Alternating humid & dry environment, higher speed priority, basic moisture protection only → S71901 CDGB/P4A non-contact seal version;

Fully enclosed clean housing with forced circulating oil supply, pursuing maximum speed → S71901 CD/P4A open stainless steel bearing;

Dry machining environment, higher load priority, no anti-rust demand → 71901 CDGA/P4A bearing steel bearing;

Predominantly radial load, higher rotational speed prioritized → S71901 ACDGA/P4A.

5.3 Lubrication Scheme

S71901 CDGA/P4A comes pre-filled with high-speed grease. Long-term grease lubrication is recommended under standard conditions. Long-term high-pressure circulating oil lubrication is not advised; continuous oil flushing will wash away built-in grease and weaken long-term lubrication performance.

For equipment running continuously at high speed, replenish compatible high-speed bearing grease periodically according to maintenance cycle. Monitor bearing temperature persistently. Replace with non-contact sealed stainless steel bearing if temperature keeps excessively high. Do not mix greases of different brands to avoid deterioration and failure.

5.4 Environmental Application Notes

Double contact seals provide basic dustproof, splash mist and condensation resistance, but long-term liquid immersion, continuous salt spray spraying and erosion by strong acid & alkali media are prohibited. External protective covers must be added for scenarios with continuous liquid flushing and chemical vapor. Stainless steel possesses good rust resistance but is not acid-alkali resistant; pitting corrosion will occur under long-term contact with salt water and cleaning agents. Keep environment dry during long equipment shutdown to prevent seal aging.

6 Daily Maintenance & Fault Troubleshooting

Carry out low-speed staged running-in after assembly, continuously monitor bearing temperature and vibration, and gradually raise speed to rated value after stable operation. Focus on temperature near sealing areas; abnormal temperature rise usually indicates excessive friction of sealing lips or oversize preload.

Replenish grease regularly according to maintenance cycle to avoid dry abrasion caused by lubricant depletion. Inspect seal appearance periodically. Replace bearing once leakage, hardening or cracking appears. Common failure causes: dry friction due to grease depletion, sealing lip abrasion by dust penetration, slow erosion of rolling contact surface by corrosive vapor, seal overheating aging triggered by excessive preload.

Set up periodic inspection plan to detect abnormal noise, rising vibration and over-temperature at early stage, preventing rapid precision loss and bearing seizure.