1 Product complete model, size, load and all standard attributes

Complete model: 7000 CD/P4ADBC

Model code interpretation

7000: 70 series ultra-small precision angular contact bearing basic specification; CD: D type high-load internal design, double-row two-point contact structure; P4A: P4A ultra-high precision tolerance grade; DBC: factory pre-assembled back-to-back configuration (<>), medium preload finished pair unit, ready for direct assembly upon arrival, no need for on-site selection and bearing adjustment.

Standard size parameters

Diameter d: 10 mm

Outer diameter D: 26 mm

Width B: 16 mm

Contact angle: 15 °

Load performance parameters

Basic rated dynamic load Cr: 6.63 kN

Basic rated static load C0r: 3.25 kN

Limit rotational speed note

Operating speed can be achieved by contacting SKF for corresponding technical reference data.

Product complete attributes

Contact type: Ordinary two-point contact

Column number: 2 columns (double-row structure)

Inner ring type: Integral inner ring, integral outer ring

Internal structure: D type high-load optimized design

Factory pre-assembled configuration: Bearing supply in a complete set, not supporting single-piece use

Factory paired arrangement: Back-to-back arrangement <>

Number of bearings in the set: 2 units

Pre-tightening state: Medium preload (factory preset, cannot be arbitrarily changed for clearance)

Tolerance grade: P4A precision grade

Base material material: Bearing steel

Surface coating: No coating

Sealing structure: No sealing, open structure

Pre-installed lubricant: None, lubrication scheme configured on-site as needed

New product indicative carbon footprint: 0.14 kg CO₂e

Net weight of logistics: 0.038 kg

eClass classification code: 23-05-08-04

UNSPSC code: 31171531

Rotational speed note: Actual operating speed is affected by lubrication method, cooling conditions, continuous load, and coaxiality of assembly. For high-speed conditions, it is recommended to配套 an oil-air lubrication system. Detailed rotational speed thresholds can be consulted in the official technical documentation of SKF.

2 NMT 7000 CD/P4ADBC structure and operating characteristics

The Japanese NMT 7000 CD/P4ADBC belongs to the 70 series ultra-small double-row pre-assembled precision angular contact bearings， featuring a 15° small contact angle design， balancing high-speed operation capability and radial load-bearing performance. The integrated inner and outer ring structure effectively enhances component rigidity， reducing the risk of assembly deformation； The D-type high-load internal raceway contour optimization further enhances dynamic load-bearing capacity compared to the basic double-row bearing， suitable for continuous stable light to medium-load high-speed conditions.

The product is factory-pre-assembled medium preload back-to-back complete units， with two sets of bearings having matching precision， factory preset preload force， ready for direct installation upon arrival， eliminating the need for on-site pairing and adjustment， significantly reducing the assembly time for the spindle. The 15° contact angle characteristic enables more stable high-speed temperature rise performance， suitable for long-term continuous low-speed fluctuations in precise rotating scenarios.

Open structure without sealing， no friction resistance from sealing components， suitable for both grease lubrication and oil-air lubrication mainstream schemes； No pre-installed lubricant， equipment manufacturers can choose the appropriate lubricating oil based on rotational speed and temperature conditions. The overall size is compact， with an outer diameter of 26 mm and an inner diameter of 10 mm， suitable for installation spaces with limited space for precision equipment.

3 Core performance advantages

1. Factory pre-assembled back-to-back medium preload unit： Factory precision matching completed， direct installation， no on-site pairing and adjustment required， reducing assembly error.

2. 15° small contact angle， excellent high-speed performance： Lower rolling friction， controllable high-speed temperature rise， suitable for small high-speed precision rotating mechanisms. 3. D-type high-capacity double-row structure: Two-point contact design for double rows, superior radial load-bearing capacity compared to single-row bearings, and stronger stability in handling combined loads.

4. P4A high-precision tolerance grade: Strict control of radial and axial runout to ensure continuous high-precision rotation of instruments and micro-spindle units.

5. Integrated inner and outer ring design: Strong overall integrity of the rings, less prone to deformation during assembly, maintaining long-term operational accuracy stability.

6. Compact miniaturized size: Inner diameter 10mm, outer diameter 26mm, suitable for precise equipment layout in limited installation spaces.

4 Main application scenarios

4.1 Micro high-speed precision spindle

Small engraving machine spindles, built-in high-speed spindles in instruments, micro-hole processing micro-rotating spindle units.

4.2 Precision inspection and laboratory equipment

Optical inspection rotating fixtures, three-coordinate auxiliary rotating mechanisms, various precision test instrument rotating shaft systems.

4.3 Compact miniaturized rotating components for small automation equipment

Micro robot joints, precision indexing micro turntables, semiconductor small transmission rotating mechanisms.

4.4 Small CNC and precision processing equipment

Micro CNC milling machine rotating components, small tool grinding equipment spindles, precision spinning machine high-speed rotating shafts.

5 Assembly specifications and usage requirements

5.1 Assembly environment and operation specifications

P4A high-precision complete bearing must be assembled in a dust-proof and clean environment. Clean all mating surfaces of the shaft neck and bearing housing of the mating surfaces of burrs, dust, and metal debris. It is recommended to use hot assembly technology. Do not directly strike the bearing raceway and working surface. Strictly control the interference fit. An excessive interference fit will damage the factory-set preload and cause increased heat; an insufficient interference fit is prone to cause external ring creep and wear. The entire set of bearings cannot be disassembled and used separately; disassembly will damage the factory-paired accuracy and preload state.

5.2 Preloading and pairing usage instructions

7000 CD/P4ADBC is a factory-pre-set medium preload back-to-back complete bearing. The preloading parameters are factory-calibrated. Do not privately grind the spacer sleeve or adjust the clearance. The back-to-back layout has good anti-overturning torque capability and is suitable for micro-spindles with slight overturning loads and suspended structures. If the working load is continuously high, it is necessary to recheck the rigidity of the shaft system and the rated life of the bearings.

5.3 Lubrication matching scheme

There is no pre-installed lubricant inside the bearing. For higher rotational speed conditions, priority should be given to using an oil-gas lubrication system; for regular continuous operation equipment, low-viscosity high-speed precision bearing grease should be selected. Different models and brands of lubricating media are prohibited from being mixed. Before replacing the lubricant, thoroughly clean the interior of the bearing.

5.4 Speed parameter explanation

This model can achieve the maximum speed. Please refer to the corresponding specifications of SKF for technical data. The actual operating speed is restricted by load, preload, heat dissipation, and lubrication conditions. It is recommended to reserve a speed safety margin for continuous full-load operation.

6 Daily operation maintenance and fault diagnosis

After assembly, conduct a low-speed no-load test run, gradually increase the speed, continuously monitor vibration, noise, and temperature changes, and confirm stability before officially starting operation. The open structure of the bearing has no dust-proof or liquid protection capabilities. When the working environment has dust, cutting fluid, or water vapor, an external protective sealing structure must be added at the shaft end.

Follow the lubrication cycle to replenish lubricating medium regularly and maintain an effective oil film on the raceway. During operation, if there is continuous abnormal noise, accuracy drift, or abnormal temperature rise, first check the assembly interference fit, preload state, foreign object intrusion, and lubrication failure issues. Do not allow the bearing to bear severe impact loads to prevent permanent deformation of the integrated ring.