1 Complete Model & Code Explanation

Model：E2.625-2Z/C3

Code Definition

E2：Optimized raceway geometry series, reduced contact stress, low vibration and low noise

625：Basic dimension of miniature deep groove ball bearing

2Z：Double-side pressed steel non-contact shield

C3：Increased radial internal clearance class

Structure：Steel shields fitted on both ends with closed end face

Supply form：Single independent bearing, no factory duplex grinding, DB/DF duplex arrangement not supported

Important reminder: E2.625-2Z/C3 is bearing steel miniature bearing with double-side steel shields, capable of bearing radial loads and moderate bidirectional axial loads. 2Z steel shields adopt clearance non-contact structure with minimum running resistance and higher limiting speed than 2RZ & 2RS rubber sealed bearings. It can only block dry coarse dust, unable to isolate fine dust, water vapor, oil mist and liquid medium. E2 improved raceway profile enhances running stability for long-term continuous high-speed operation. Steel shields are permanently riveted, non-detachable for cleaning; on-site re-lubrication is not available.

Basic Parameters

Bore d：5 mm

Outer diameter D：16 mm

Width B：5 mm

Bearing type：Single-row deep groove ball bearing

Number of rows：Single row

Bore form：Straight cylindrical bore

Seal arrangement：2Z double pressed steel non-contact shield

Cage：Stamped steel cage

Radial internal clearance：C3 increased clearance

Material：Bearing steel

Surface coating：Uncoated

Pre-installed lubricant：General long-service grease

Relubrication capability：On-site re-greasing unavailable

Duplex arrangement：Not supported, single unit operation only

Basic dynamic load rating：0.088 kN

Basic static load rating：0.036 kN

Reference speed：85 000 r/min

Limiting speed：59 000 r/min

Net weight：0.00025 kg

Indicative carbon footprint：0.00062 kg CO₂e

eClass code：23-05-08-01

UNSPSC code：31171504

Series Suffix Comparison

625：Open type without protection, highest rotational speed, no dust resistance

E2.625：E2 optimized raceway, open construction

E2.625-Z/C3：Single steel shield, C3 clearance

E2.625-2Z/C3：Double steel shield, E2 raceway optimization, C3 increased clearance (this model)

625-2RZTN9/HC5C3WTF1：Double non-contact rubber seal, wide-temperature low-temperature grease

625-2RS：Double contact rubber seal, dust & moisture resistant, lower allowable speed

2 Structure & Operating Characteristics

Japan NMT E2.625-2Z/C3 is developed on standard 625 dimension platform with E2 modified raceway curve, double-side 2Z pressed steel shields and C3 increased radial clearance, targeted at high-speed miniature rotary mechanisms under dry and clean environment. Optimized raceway profile improves contact condition between balls and raceways, reduces stress concentration, delivering better vibration and noise performance than ordinary standard 625 bearings during continuous high-speed rotation.

A tiny fixed clearance exists between double-side steel shields and inner ring without contact friction, achieving outstanding high-speed performance. Nevertheless, fine dust and moisture can slowly penetrate through clearance, so it is not recommended for heavy dust or humid working conditions. C3 increased radial clearance fits assembly conditions with obvious temperature rise at high speed, compensating thermal expansion of shaft and bearing to avoid seizure caused by insufficient clearance. Stamped steel cage features stable strength and excellent centrifugal resistance for sustained high-speed applications. The bearing mainly withstands radial loads and bears certain bidirectional axial loads. Long-term overspeed operation is prohibited.

3 Core Performance Advantages

1. E2 optimized raceway geometry reduces contact stress, lowers operation vibration and noise, provides superior durability compared with standard basic bearings.

2. Double-side 2Z steel shields with non-contact clearance design realize ultra-low friction loss; limiting speed exceeds all rubber sealed bearings.

3. C3 increased radial clearance adapts to high-speed temperature rise and effectively prevents thermal seizure.

4. All-metal shielding components resist high temperature without rubber aging failure, suitable for clean and dry medium-high temperature environment.

5. Symmetrical shielding structure on both ends with no installation orientation required, simplifying assembly for compact equipment.

6. Standard 625 outer dimension brings great interchangeability for equipment upgrade replacing ordinary 625 series bearings.

4 Typical Application Fields

4.1 Miniature High-Speed Motors

Small cooling fan motors, portable air pump motors, model brushless spindles.

4.2 Precision Office & Automation Components

Mini printer rollers, small conveying guide wheels, automation micro rotary shafts.

4.3 Small Laboratory Instruments

Optical gimbal rotary shafts, small rotary assemblies for inspection equipment, transmission units of portable analytical instruments.

4.4 Light-Duty Small Electric Devices

Mini handheld polishing modules, small household high-speed transmission mechanisms.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

Keep assembly environment clean to prevent hard particles entering the bearing. Apply pressing force onto bearing ring end faces; knocking or prying steel shields on both sides is forbidden to avoid shield deformation and clearance deviation. Properly control interference between shaft and housing. When selecting C3 clearance version, excessive interference fit should be avoided otherwise the advantage of increased clearance will be offset. Symmetrical 2Z double shield structure has no specified installation direction.

5.2 Selection Guidance

Ultimate rotational speed & extremely clean environment → E2.625 open bearing

Single-side dust protection, dry high-speed working condition → E2.625-Z/C3

Dry clean environment, blocking coarse dust on two sides, priority on high limiting speed → E2.625-2Z/C3 (this model)

Environment with fine dust, alternating hot and cold, higher dust protection required → 2RZ non-contact rubber seal type

Working condition with water vapor and oil mist → 2RS contact rubber sealed bearing

5.3 Lubrication Instruction

Pre-filled with standard long-service grease at factory, supporting long maintenance-free operation under clean and dry standard conditions. 2Z steel shields are permanently riveted closed structure. Dismantling shields, cleaning with organic solvent and on-site re-greasing are strictly prohibited. Long-term overspeed and continuous high temperature accelerate grease oxidation and drying, drastically shortening bearing service life.

5.4 Environmental Application Notes

2Z steel shields only block dry coarse solid debris, incapable of preventing fine dust, water vapor, oil mist and liquid water penetration. Bearing steel has no inherent anti-rust performance. Even with double-side shields, internal rust easily occurs under high humidity. Sealed bearings shall be adopted for humid scenarios. No rubber parts mean no rubber aging risk, yet lubricant will still degrade under long-time high temperature.

6 Daily Maintenance & Fault Troubleshooting

Carry out low-speed running-in test after assembly; gradually increase to rated working speed only after confirming no abnormal noise and temperature rise. Typical faults of this model include gradually amplified rotation noise, sluggish rotation and abnormal temperature surge.

Common failure causes: continuous invasion of fine dust leading to raceway abrasion, grease drying under prolonged high temperature, insufficient clearance caused by improper fitting tolerance, sustained excessive axial load. Once raceway pitting or cage deformation occurs, the bearing cannot be repaired and replacement is recommended.