1 Complete Model, Dimensions, Loads & Technical Parameters

Full Model: 7005 ACE/P4ADGA

Model Code Explanation

7005: Base specification of 70 series precision angular contact ball bearing;

ACE: 25° contact angle, E-type high-speed two-point contact raceway geometry;

P4A: bearing steel material, P4A ultra-precision tolerance grade;

DGA: Duplex General Arrangement, duplex universal matched bearing set, compatible with DB/DF/DT assembly modes.

Standard Dimension Parameters

Bore d: 25 mm

Outer diameter D: 47 mm

Width B: 24 mm

Contact angle: 25 °

Load Performance Data

Basic dynamic load rating Cr: 12.7 kN

Basic static load rating C0r: 7.8 kN

Speed note: Contact SKF to obtain official technical documents for achievable operating speed

Full Product Attributes

Contact style: standard two-point contact

Row: 2 rows (duplex matched unit)

Race structure: integrated inner ring and outer ring

Internal design: E-type high-speed optimized design

Interchangeable matched configuration: available, back-to-back (<>), face-to-face (><), tandem (>>)

Matching arrangement: universal match

Quantity of bearings in set: 2 units

Preload / clearance specification: ultra-light preload

Tolerance class: P4A precision grade

Material: bearing steel

Coating: uncoated

Seal: open type without seals

Pre-filled lubricant: none, lubrication configured on demand

Indicative carbon footprint for new product: 0.55 kg CO₂e

Net weight: 0.149 kg

eClass code: 23-05-08-04

UNSPSC code: 31171531

Speed note: Actual operating speed is affected by lubrication mode, heat dissipation, continuous load and assembly coaxiality. Confirm reference limiting speed with SKF before formal selection.

2 Structure & Operating Characteristics

Japan NMT 7005 ACE/P4ADGA is a 25° E-type high-speed duplex universal matched precision angular contact bearing with integrated bearing steel inner and outer rings. The 25° contact angle balances axial load capacity and high-speed performance. The optimized E-type high-speed raceway improves rolling contact condition, reduces friction disturbance and suppresses temperature rise and vibration under high-speed operation. Supplied as a universal matched duplex set. The two precision selected bearings can be installed flexibly in three layouts according to working conditions:

Back-to-back (<>): wider supporting span, superior anti-overturning performance for heavy overturning loads;

Face-to-face (><): compact axial dimension, good tolerance to assembly coaxial error for limited axial space;

Tandem (>>): superimposed axial load capacity for sustained unidirectional heavy axial thrust.

Ultra-light preload is preset at factory to minimize frictional heat and restrain micro-slip of rolling elements, suitable for long-term continuous high-speed operation. Open non-sealed design eliminates friction loss caused by seals to maximize limiting speed. No pre-filled lubricant inside; high-speed grease or oil-air lubrication system can be selected according to application.

The two bearings form an integral matched set. Splitting and mixing with other single bearings is not recommended, otherwise inconsistent precision will lead to increased vibration and rapid accuracy loss.

3 Core Performance Advantages

1. E-Type High-Speed Raceway & 25° Contact Angle: Balanced load capacity and high-speed capability, excellent temperature control during prolonged high-speed operation.

2. Duplex Universal Matched Set: One set supports three assembly layouts, compatible with various shaft designs and easy inventory management.

3. Factory Ultra-Light Preload: Low friction and low heat generation, stable performance during long continuous high-speed operation.

4. Bearing Steel Body: High mechanical strength, good wear resistance and reliable dimensional stability.

5. P4A Ultra-Precision Grade: Strict control over radial and axial runout to ensure long-term high-precision rotation.

6. Integrated Ring Structure: High rigidity, small elastic deformation at high speed to maintain stable rotary accuracy.

7. Open Seal-Free Construction: No extra friction loss, higher limiting speed, compatible with advanced oil-air lubrication solutions.

4 Typical Application Scenarios

4.1 Medium & Small High-Speed Precision Machine Tool Spindles: High-speed engraving & milling spindles, PCB machining spindles, small high-speed grinding spindles, precision woodworking high-speed spindles.

4.2 Light-Duty High-Speed Automated Rotary Mechanisms: High-speed precision indexing tables, lightweight collaborative robot joints, rotary units for high-speed winding and conveying equipment.

4.3 High-Speed Precision Optical & Testing Equipment: Optical scanning rotary platforms, rotary mechanisms of precision test fixtures, rotary support assemblies for small high-speed fluid equipment.

4.4 Medium & Small High-Speed General Precision Equipment: High-speed textile rotary shafts, high-speed rotary support components for compact precision medical instruments.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A high-precision duplex universal matched bearings must be assembled in dust-free clean environment. Remove burrs, dust and metal debris on shaft journals, housing bores and spacer mating surfaces. Thermal mounting is preferred. Direct impact on raceways, rolling elements and working surfaces is prohibited. Use bearings as a matched set; avoid splitting and mixing with other bearings. Control interference fit properly: excessive interference causes sharp temperature rise; insufficient interference results in outer ring creep and damages preset preload.

5.2 Matching Structure & Preload Instructions

This model is universal matched duplex bearing set. Select back-to-back (<>), face-to-face (><) or tandem (>>) layout based on load conditions. Calculate axial force and overturning moment of shaft system before assembly to confirm optimal arrangement. Ultra-light preload is factory preset, ideal for applications prioritizing rotational speed with medium-light loads. Contact manufacturer for customization if different preload grade is required.

5.3 Lubrication Matching Solutions

No pre-filled lubricant inside bearing. High-speed low-viscosity grease fits intermittent low-speed operation; oil-air circulating lubrication system is recommended for long-term continuous high-speed operation. Mixing different types of lubricants is forbidden. Fully clean bearing assembly before lubricant replacement.

5.4 Speed Parameter Note

Obtain reference limiting speed data directly from SKF. Reserve sufficient safety margin for continuous operation. Reduce operating speed under heavy load or poor heat dissipation to prevent premature bearing fatigue failure.

6 Daily Maintenance & Fault Troubleshooting

Carry out low-speed no-load trial run after assembly, increase speed gradually and monitor vibration, noise and temperature rise. Formal operation can be started only under stable working status. Open design does not provide built-in protection against dust and cutting fluid. External sealing must be installed at shaft end if dust, cutting fluid or moisture exists in working environment.

Replenish and replace lubricants periodically according to service cycle to maintain complete oil film on raceways. If continuous abnormal noise, accuracy decline or overheating occurs, sequentially check assembly interference, bearing layout, mounting direction, foreign matter intrusion and lubrication failure. Avoid severe impact loads to prevent permanent deformation of bearing rings.