1 Complete Model & Code Explanation

Model: S71901 CDGB/P4A

Code Definition

S71901: Corrosion-resistant specification of S719 stainless steel miniature extra-light series angular contact ball bearing

CD: Standard raceway geometry with 30° contact angle, outstanding axial load capacity for heavy axial thrust conditions

GB: Double-sided non-contact seal construction, pre-filled long-life precision grease from factory, eliminating initial lubrication piping layout

P4A: ISO P4A super precision tolerance grade, high-precision single unit, supporting field free duplex assembly of DB/DF/DT

Supply form: Individually packed single bearing for universal matching; preload grade B, preload adjusted via measured load method

Important reminder: This bearing is universal matchable sealed single unit without factory duplex lapping. When assembling two bearings with precision spacers, adjust preload to grade B standard by measured load. Compared with Grade A preload, Grade B generates lower temperature rise and fits long continuous operation. Sealed structure is not suitable for oil-air circulating lubrication; if continuous external forced oil supply is required, GA open suffix model should be selected first. The load rating of stainless steel version is slightly lower than bearing steel counterpart of identical dimension, not recommended for sustained heavy loads. The seal cannot resist long-term erosion by strong acid, alkali or high-concentration salt spray.

Core 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 design: CD standard raceway structure with 30° contact angle

Contact form: Two-point standard contact

Number of rows: Single row

Ring structure: Integrated inner ring, integrated outer ring

Seal arrangement: Double-sided non-contact seal

Seal type: Non-contact labyrinth rib seal

Base material: Martensitic stainless steel

Surface coating: Uncoated

Pre-installed lubricant: Factory pre-filled long-life grease for precision rotary shafts

Duplex capability: Universal matchable bearing, available for back-to-back (<>), face-to-face (><), tandem (>>) layout; no factory preset duplex arrangement, grade B axial clearance/preload adjusted by measured load

Precision class: P4A

Basic dynamic load rating: 2.45 kN

Basic static load rating: 1.12 kN

Speed reference: Contact manufacturer for attainable rotational speed reference data

Net weight: 0.0100 kg

Indicative carbon footprint for new unit: 0.037 kg CO₂e

eClass code: 23-05-08-04

UNSPSC code: 31171531

Suffix Comparison within Series

S71901 CDGB/P4A: Stainless steel, 30° contact angle, double-sided non-contact seal, pre-filled grease, universal matchable single unit P4A precision, Grade B preload (this model)

S71901 CDGA/P4A: Stainless steel open bearing with Grade A preload

S71901 CDGC/P4A: Stainless steel open single bearing with Grade C preload

S71901 CDGBQ/P4A: Stainless steel factory duplex matched sealed bearing set

S71901 ACDGB/P4A: Stainless steel 25° contact angle double-sided sealed bearing with Grade B preload

71901 CDGB/P4A: Bearing steel 30° contact angle sealed bearing with Grade B preload, no corrosion resistance

2 Structure & Operating Characteristics

Japan NMT S71901 CDGB/P4A belongs to S719 series martensitic stainless steel super precision angular contact ball bearing. It adopts CD 30° contact angle raceway geometry with prominent axial load capacity, ideal for rotary mechanisms subjected to high proportion of axial load. Inner and outer rings are integrally formed, raceways processed by ultra-precision mirror grinding to reduce vibration and noise during high-speed rotation.

The bearing features GB double-sided non-contact seal design. Compared with contact seals, operating friction is smaller; sealing ribs do not contact rings directly to reduce heat generation. Long-life grease is pre-sealed at factory, ready for medium-low speed continuous operation after installation and simplifies lubrication layout. The sealing structure blocks dust and ambient moisture, adapting to indoor condensation and slightly humid environments. Nevertheless, stainless steel only provides basic rust protection and cannot withstand long-term liquid immersion, salt spray or aggressive chemical media.

As universal matchable single bearing, multiple duplex configurations can be flexibly assembled with Grade B preload. Grade B preload delivers moderate axial preload force with excellent temperature control, suitable for uninterrupted long-term operation; rigidity is inferior to Grade A preload, fitting equipment with heavy axial thrust, sensitive to temperature rise and without extreme load requirements. Stainless steel material achieves slightly lower load ratings than bearing steel bearings of same size. Limited grease volume inside sealed structure leads to lower attainable speed versus GA open bearings. Continuous oil-air or oil injection circulating lubrication is prohibited.

3 Core Performance Advantages

1. CD 30° contact angle raceway structure: Superior axial load capacity for combined loads dominated by axial thrust.

2. GB double-sided non-contact sealed construction: Low running resistance, prevents dust and ambient moisture ingress and slows raceway rusting.

3. Factory pre-filled long-life grease: Directly operable after mounting, eliminating initial grease filling and lowering supporting costs.

4. Martensitic stainless steel substrate: Basic rust and moisture resistance, suitable for dry to slightly humid environments with condensation.

5. P4A super precision tolerance: High dimensional accuracy and small rotary runout to guarantee positioning and rotation precision of precision equipment.

6. Grade B standard preload solution: Stable and controllable operating temperature rise, adapted to long continuous operation and mitigating accuracy loss caused by overheating.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Assembly of P4A super precision stainless steel sealed angular contact bearings is recommended to be carried out in constant-temperature clean workshops with strict dust control. Thermal mounting is preferred; direct impact on raceways and sealing areas is forbidden. Avoid squeezing sealing ribs during assembly to prevent deformation and loss of dust & moisture protection.

Important reminder: No factory duplex lapping for sealed single bearings. When two bearings are combined, match precision spacers and adjust preload to Grade B standard via measured load to guarantee uniform load sharing.

5.2 Assembly Combination & Preload Instructions

Supply condition: Independent sealed single bearing, universal for duplex arrangement

Optional layout: DB back-to-back / DF face-to-face / DT tandem

Preload control method: Measured load, grade B preload

Selection guidance:

Slightly humid environment, condensation, heavy axial load, rust prevention required → prioritize S71901 CDGB/P4A;

Intermittent high speed equipped with oil-air/oil injection external lubrication system → select open type S71901 CDGA/P4A;

Low load, limited budget and moderate rigidity requirement → adopt S71901 CDGC/P4A;

Mass standardized equipment without on-site preload adjustment → factory duplex matched S71901 CDGBQ/P4A;

Predominantly radial load, higher limiting speed required → select 25° contact angle S71901 ACDGB/P4A;

Dry clean environment without moisture, heavy load applications → select bearing steel 71901 CDGB/P4A;

Salt spray, chemical splash, long-term liquid immersion → this model is not applicable, full anti-corrosion solution required.

5.3 Lubrication Matching Scheme

Special grease for precision rotary shafts is pre-filled inside bearing upon delivery. No continuous external oil supply is needed under standard working conditions. For long-hour continuous operation with rising temperature, periodic grease replenishment structure can be designed. Continuous circulating oil-air lubrication is prohibited; persistent external oil flow will flush out internal grease and trigger premature rust and fatigue failure. Mixing greases of different base oil types or brands is forbidden.

5.4 Speed & Environmental Application Notes

Non-contact seals introduce slight air flow resistance, resulting in lower attainable speed compared with open stainless steel bearings of same specification. It provides dustproof and basic rust & moisture resistance. Do not directly apply under liquid immersion, continuous splash, high-concentration salt spray or acid & alkali corrosion conditions. External housing protection is mandatory in environments with high dust concentration or persistent high humidity to reduce direct contact between moisture and bearings.

6 Daily Maintenance & Fault Troubleshooting

Carry out low-speed staged running-in after assembly, continuously monitor temperature rise and vibration. Do not raise speed to rated working level until operation stabilizes. Pre-filled grease has fixed service life; grease replenishment or bearing replacement shall be arranged once service duration expires.

Grade B preload excels in temperature control, yet preload force will gradually decay under long-term axial impact loads. Regular recheck of rotary accuracy is recommended. Stainless steel only slows rust instead of fully isolating moisture; once seals are damaged, moisture ingress easily causes raceway rust, accompanied by increased vibration.

Common abnormal triggers: damaged sealing ribs during assembly, internal grease washed away by continuous external oil supply, excessive preload causing overheating, poor coaxiality between shaft and housing, operation beyond limit speed, seal aging and water ingress leading to rust under long-term high humidity.

Formulate periodic accuracy inspection and grease replenishment schedule to prevent abnormal noise, rotary accuracy drop, seizure and rust failure in advance.