1 Complete Model, Dimensions, Loads & Technical Parameters

Full Model: 7005 ACD/P4ADFB

Model Code Explanation

7005: Base specification of 70 series precision angular contact bearing; ACD: 25° contact angle, D-type high-load two-point contact raceway geometry; P4A: bearing steel, P4A ultra-precision tolerance grade; DFB: Duplex Face-to-Face Bundle, factory fixed face-to-face pre-matched set, disassembly and mixed use are prohibited.

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: 14.8 kN

Basic static load rating C0r: 10 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: D-type high-load optimized design

Interchangeable matched configuration: not available (fixed factory matched set)

Matching arrangement: face-to-face (><)

Quantity of bearings in set: 2 units

Preload / clearance specification: 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: 0.57 kg CO₂e

Net weight: 0.154 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 ACD/P4ADFB is a 25° D-type high-load duplex face-to-face pre-matched precision angular contact bearing with integrated bearing steel inner and outer rings. The 25° large contact angle provides excellent axial load capacity for heavy bidirectional axial load conditions. Optimized D-type high-load raceway improves contact stress distribution and extends load capacity and fatigue life. The bearings are factory pre-matched in face-to-face (DF) configuration. Do not split the set and interchange with other single bearings.

Features of face-to-face (><) layout: compact structure, good tolerance for assembly coaxial error, capable of bearing bidirectional axial loads with moderate anti-overturning performance, suitable for medium-small spindle structures with limited axial installation space and bidirectional loads.

Light preload is preset at factory to suppress rolling element slip during high-speed rotation and balance rotational accuracy and frictional heat. 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.

Splitting the duplex set will invalidate factory matching accuracy, resulting in increased vibration, accuracy loss and shortened service life.

3 Core Performance Advantages

1. D-Type High-Load Raceway & 25° Contact Angle: Strong axial load capacity, uniform contact stress distribution, outstanding durability under heavy loads.

2. Factory Fixed DF Face-to-Face Pre-Matched Set: Precision matched before delivery, saving on-site matching work and ensuring consistent assembly quality.

3. Standard Factory Light Preload: Prevents rolling element sliding, balances precision and temperature rise for continuous high-speed operation.

4. Bearing Steel Body: High strength and wear resistance, stable performance under impact and heavy loads.

5. P4A Ultra-Precision Grade: Strict control over radial and axial runout to maintain long-term spindle precision.

6. Integrated Ring Structure: High rigidity, minimal deformation under heavy load to sustain stable rotary accuracy.

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

4 Typical Application Scenarios

4.1 Medium & Small Precision Machine Tool Spindles: Spindles of small machining centers, precision CNC milling machines, small CNC internal and external grinding machines.

4.2 Heavy-Duty Rotary Mechanisms for Automation Equipment: Medium precision indexing turntables, heavy-duty rotary fixtures for automation, joint support units of medium-sized robots.

4.3 Rotary Components of Precision Forming Equipment: Rotary mechanisms for medium-small precision injection molding machines, auxiliary rotary supports for die casting equipment.

4.4 Medium & Small General Precision Heavy-Duty Machinery: Precision high-speed textile rotary shafts, rotary support assemblies for small high-pressure fluid equipment.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A high-precision duplex face-to-face pre-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. Do not split the set for mixed assembly 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 factory fixed as face-to-face (><) duplex set. Layout conversion to back-to-back or tandem is not supported. Calculate bidirectional axial force and overturning moment of the shaft system before assembly to verify suitability for DF arrangement. Light preload is preset; no adjustment required under normal working conditions. Contact manufacturer for customization if different preload level is needed.

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 mounting direction, foreign particle intrusion and lubrication failure. Avoid severe impact loads which cause permanent ring deformation.