1 Complete Model, Dimensions, Loads & Technical Parameters

Full Model: 7005 ACE/P4ADGA

Model Code Explanation

7005: Base specification of 70 series precision angular contact bearing; ACE: 25° contact angle, E-type high-speed two-point contact raceway geometry; P4A: bearing steel, P4A ultra-precision tolerance grade; DGA: Duplex General Arrangement, duplex universal matched set, supports DB/DF/DT assembly configurations.

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 technical data of achievable operating speed

Full Product Attributes

Contact style: standard two-point contact

Row: 2 rows (duplex matched unit)

Race structure: integrated inner ring, integrated 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, 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. Optimized E-type high-speed raceway improves rolling contact condition, reduces friction disturbance and suppresses temperature rise and vibration at high speed. Supplied as universal matched duplex set. The two matched bearings can be freely assembled into back-to-back, face-to-face or tandem layouts according to working conditions.

Back-to-back (<>): wider support span, excellent anti-overturning performance for heavy overturning load;

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

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

Ultra-light preload is preset at factory to minimize frictional heat at high speed and restrain micro-slip of rolling elements, suitable for long continuous high-speed operation. Open seal-free construction eliminates sealing friction to maximize limiting speed. No pre-filled lubricant inside; high-speed grease or oil-air lubrication is recommended.

The two bearings form a matched set. Splitting and mixing with other single bearings is not recommended to avoid precision deviation.

3 Core Performance Advantages

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

2. Duplex Universal Matched Set: One set supports three assembly layouts, strong versatility for various shaft designs and inventory management.

3. Factory Ultra-Light Preload: Low friction and low heat generation, stable performance for prolonged high-speed continuous running.

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

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

6. Integrated Ring Structure: Good rigidity, minimal deformation at high speed to sustain stable rotary accuracy.

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

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 units, lightweight collaborative robot joints, high-speed winding and conveying rotary units.

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

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

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A high-precision duplex universal matched bearings must be installed 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 the set as paired units; avoid splitting and mixing with other bearings. Control interference fit properly: excessive interference leads to sharp temperature rise; insufficient interference causes outer ring creep and destroys preload status.

5.2 Matching Structure & Preload Instructions

This model is universal matched duplex set. Select back-to-back (<>), face-to-face (><) or tandem (>>) layouts according to 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 high-speed priority and medium-light load applications. Contact manufacturer for customization if different preload level is required.

5.3 Lubrication Matching Solutions

No pre-filled lubricant inside bearing. High-speed low-viscosity grease is applicable for intermittent low-speed operation; oil-air circulating lubrication system is recommended for long-term continuous high-speed operation. Mixing different grades of lubricants is forbidden. Thoroughly 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 fatigue failure.

6 Daily Maintenance & Fault Troubleshooting

Carry out low-speed no-load trial run after assembly, increase speed gradually, monitor vibration, noise and temperature rise. Formal operation can start only under stable working condition. Open design lacks built-in dust and coolant protection. External sealing must be installed at shaft end when dust, cutting fluid or moisture exists.

Replenish and replace lubricants periodically according to service cycle to maintain complete oil film on raceways. If continuous abnormal noise, precision decline or overheating occurs, sequentially inspect assembly interference, bearing layout, mounting direction, foreign particle intrusion and lubrication failure. Avoid severe impact loads which cause permanent ring deformation.