1 Complete Model, Dimensions, Loads and Technical Specifications

Full Model: 7000 CD/HCP4ADGA

Model Code Explanation

7000: 70 series miniature precision spindle specification;

C: 15° standard contact angle balancing high speed and axial rigidity;

D: NMT self-developed D-type high capacity internal geometry for optimized ball contact path;

HCP4A: Super precision P4A tolerance class;

DGA: Factory universal matched bearing set, two bearings selected from the same batch, supporting three installation arrangements without extra sorting.

Supplied as one set containing two single bearings with factory pre-matching.

Single Bearing Dimensions

Bore d: 10 mm

Outer diameter D: 26 mm

Width B: 8 mm

Contact angle: 15°

Load Ratings (per bearing)

Basic dynamic load rating Cr: 4.1 kN

Basic static load rating C0r: 1.66 kN

Full Product Specifications

Contact type: standard two-point contact

Row: single row

Race construction: integral inner ring and outer ring

Internal structure: NMT D-type high capacity design

Matching form: DGA universal matched set (2 pcs/set), configurable as back-to-back (<>), face-to-face (><), tandem (>>)

Precision class: P4A super precision

Material: high purity bearing steel

Coating: uncoated

Seal: open seal-free construction

Pre-filled lubricant: none

Speed note: attainable speed is affected by lubrication, preload, load and assembly coaxiality. Contact NMT engineering for working condition parameters.

2 Structure & Operating Characteristics

Japan NMT 7000 CD/HCP4ADGA is a pre-matched super precision angular contact bearing set. Two 7000 CD/P4A bearings undergo unified dimensional screening and rotational accuracy matching before delivery. The DGA universal matching eliminates on-site manual selection, reduces assembly error and ensures consistent running performance of the set.

The 15° two-point contact geometry balances ultimate speed and combined load capacity, delivering smooth rolling friction and excellent shaft runout control under high speed. Integral seamless race construction offers uniform rigidity and strong resistance to deformation caused by alternating loads and overturning moment, suitable for long-term continuous precision operation. The optimized D-type internal structure expands effective contact area and improves load capacity within compact envelope, solving insufficient rigidity issues of miniature spindle bearings.

All bearings go through stabilization heat treatment, mirror race superfinishing and micron-level sorting. Dimensional deviation of matched set strictly meets P4A super precision standard. Open seal-free and non pre-greased design supports oil-air ultra-high-speed lubrication as well as clean grease lubrication to satisfy diverse requirements of precision processing and testing equipment.

The outstanding advantage of DGA universal matched set lies in flexible assembly. Users can switch three typical layouts only by adjusting installation direction without replacing spacers or components, adapting to different requirements on spindle rigidity, axial load and anti-overturning performance.

3 Core Performance Advantages

Factory DGA universal pre-matching: Two bearings are precisely screened and matched at factory, ensuring high consistency and reducing assembly difficulty.

P4A super precision grade: Micron-level dimensional and rotational accuracy minimizes spindle runout to guarantee precision machining and measurement.

15° contact angle & D-type high capacity structure: Improved dynamic and static load capacity within compact size, balancing high speed and structural rigidity.

High-rigidity integral race: Seamless one-piece forming resists impact and alternating deformation with low precision attenuation over service time.

Multi-purpose set with three optional layouts: Flexible back-to-back, face-to-face and tandem arrangement for various miniature spindle designs.

Open structure without pre-filled lubricant: Fully compatible with oil-air high-speed lubrication and clean grease lubrication.

Uncoated bearing steel body: Avoids raceway contamination caused by coating peeling and provides good compatibility with various lubricants.

4 Typical Application Fields

4.1 Miniature Precision Machine Tool Spindles

Small high-speed engraving & milling spindles, PCB micro drilling spindles, miniature internal grinding heads, small CNC precision rotary units

4.2 High-Speed Mini Drive Motors

Precision servo micro motors, high-speed engraving spindle motors, built-in rotary motors for testing instruments

4.3 Precision Measuring & Laboratory Equipment

Vision alignment platforms, small precision dividing heads, rotary test fixtures, high-precision dimensional inspection devices

4.4 Automated Precision Transmission Mechanisms

Rotary shafts for electronic component processing, precision rotary transfer modules, small cam rotary stations

4.5 Electronic & Light Industry Precision Equipment

Small precision mold finishing machines, precision textile rotary shafts, precision rotary units for packaging automation

5 Assembly, Preload & Lubrication Guidelines

5.1 Assembly Environment

P4A matched bearings should be assembled in dust-free constant-temperature clean space. Thoroughly remove dust, metal chips and oil from journals, housings and spacer surfaces. Thermal mounting is recommended. Never strike raceways or rolling elements directly to prevent surface damage. Use two bearings as a complete set; avoid mixing with bearings from other batches.

5.2 DGA Layout & Preload Instruction

Back-to-back (<>): excellent anti-overturning rigidity for applications with offset radial loads;

Face-to-face (><): uniform load distribution for high-precision positioning;

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

Light preload is recommended for high-speed spindles. Control preload magnitude by adjusting spacer thickness. Excessive preload will cause abnormal temperature rise. Consult NMT engineers for customized preload solutions.

5.3 Lubrication Selection

No pre-filled grease inside bearings. Oil-air circulating lubrication is preferred for ultra-high speed conditions. Low volatility high-speed spindle grease is suitable for medium-low speed precision machining and clean environment. Do not mix different types of lubricants. Completely clean residual grease before switching lubrication medium.

5.4 Speed Notice

The maximum attainable speed is dynamic, subject to lubrication type, preload magnitude, continuous load and assembly coaxiality. Contact NMT for reference speed range according to actual equipment conditions.

6 Maintenance & Failure Reminders

Monitor vibration, noise and temperature rise during trial operation to eliminate assembly coaxial error timely. The open design has no built-in dust or coolant protection. Install external shielding if dust or cutting fluid exists to prevent foreign particle intrusion and raceway pitting.

Replenish or replace lubricant periodically to maintain effective oil film. If abnormal noise, precision drift or overheating occurs, inspect lubrication status, assembly accuracy and contamination first. Avoid long-term impact loads to protect raceway precision and extend service life.