1 Complete Model, Dimensions, Loads & Technical Parameters

Full Model: 7003 CD/HCP4ADBA

Model Code Explanation

7003: Base specification of 70 series precision angular contact bearing; CD: 15° contact angle, D-type high-load two-point contact raceway geometry; HCP4A: composite material, P4A ultra-precision tolerance grade; DBA: Duplex Back-to-Back, factory preset back-to-back matched set with ultra-light preload. Two bearings are precisely selected at factory, and the matching layout cannot be modified arbitrarily.

Standard Dimension Parameters

Bore d: 17 mm

Outer diameter D: 35 mm

Width B: 20 mm

Contact angle: 15 °

Load Performance Data

Basic dynamic load rating Cr: 11.1 kN

Basic static load rating C0r: 6.55 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

Universal matched bearing: unavailable (fixed factory matching)

Matching arrangement: back-to-back <>

Quantity of bearings in set: 2 units

Preload / clearance specification: ultra-light preload

Tolerance class: P4A precision grade

Material: composite material

Coating: uncoated

Seal: open type without seals

Pre-filled lubricant: none, lubrication configured on demand

Indicative carbon footprint for new product: 0.24 kg CO₂e

Net weight: 0.065 kg

eClass code: 23-05-08-03

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 7003 CD/HCP4ADBA is a D-type duplex precision angular contact bearing of 70 series with 15° contact angle, pre-set as back-to-back <> arrangement with ultra-light preload upon delivery. The 15° small contact angle brings low rolling resistance and outstanding high-speed performance with superior radial load capacity, supporting combined radial and bidirectional axial loads. Optimized D-type raceway evenly distributes contact stress of rolling elements, reduces stress concentration and improves running stability and load capacity. Integrated inner and outer rings maintain stable rigidity and minimize assembly deformation to sustain long-term high-precision rotation.

Back-to-back duplex arrangement provides wider effective support span and excellent resistance to overturning moment, suitable for high-speed spindle systems under bending moment and lateral load. Ultra-light preload significantly lowers friction heat generation under high-speed conditions and alleviates interference to shaft accuracy caused by thermal elongation, prioritized for equipment with long-term ultra-high-speed continuous operation. Compared with medium preload versions, system rigidity is slightly reduced, making it ideal for light-load, high-speed equipment sensitive to temperature rise. Open seal-free design eliminates friction loss from sealing elements and maximizes speed potential. No pre-filled lubricant inside; users can select high-speed grease or oil-air lubrication according to operating conditions.

The matched bearing set is precisely calibrated at factory. Do not use separately or change assembly layout without authorization. Unauthorized modification will destroy preset preload, resulting in increased vibration, precision degradation and shortened service life.

3 Core Performance Advantages

1. Factory Pre-Matched Back-to-Back Duplex Set: Two bearings precision-selected, eliminating on-site lapping and directly adapting to back-to-back support structure assembly.

2. 15° Small Contact Angle with D-Type Raceway: Low rolling resistance, prominent high-speed performance and excellent radial load capacity, balancing load capacity and limiting speed.

3. Standard Ultra-Light Preload Class: Low friction heat at high speed, suppress thermal deformation, suitable for long-term continuous ultra-high-speed operation.

4. Excellent Anti-Overturning Moment Capacity: Back-to-back layout widens support distance, stably bearing bending moment and lateral overturning load.

5. P4A Ultra-Precision Grade: Strict control over radial and axial runout to maintain stable high-precision rotation of equipment.

6. Composite Bearing Material: Lighter self-weight reduces rotational inertia, featuring remarkable lightweight advantage and lower carbon footprint.

7. Open Seal-Free Construction: No extra friction resistance to fully realize ultra-high-speed performance, compatible with advanced lubrication solutions such as oil-air lubrication.

4 Typical Application Scenarios

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

4.2 High-Speed Automated Precision Rotary Mechanisms: High-speed precision indexing devices, miniature high-speed robot joints, high-speed rotary support shafts for semiconductor equipment.

4.3 Optical & High-Precision Inspection Equipment: High-speed image scanning spindles, high-speed rotary units of optical inspection platforms, lightweight precision test fixtures.

4.4 Lightweight High-End Precision Equipment: Spindles of high-speed textile machinery, transmission support components for miniature lightweight precision medical devices.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A high-precision duplex 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 complete matched set; avoid mixing split bearings with other batches. Control interference fit properly: excessive interference leads to sharp temperature rise; insufficient interference causes outer ring creep and damages preload stability.

5.2 Matching Structure & Preload Instructions

This model is factory fixed as back-to-back <> duplex configuration with ultra-light preload. Do not convert to face-to-face or tandem arrangement without approval. Back-to-back layout features wider support span and stronger resistance to overturning moment, suitable for spindles with lateral force and bending moment.

Preload value is precisely calibrated at factory. Do not grind spacers to adjust preload class. Ultra-light preload is designed for light-load high-speed scenarios; re-evaluate bearing preload grade when load increases significantly.

5.3 Lubrication Matching Solutions

No pre-filled lubricant inside bearing. Special high-speed low-viscosity grease can be adopted for short-period low-speed operation; oil-air circulating lubrication system is recommended for long-term continuous ultra-high-speed operation. Mixing different types or 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.