Product Overview

The NMT 7012 CDGB/HCP4A is an open, universally matchable single-row super-precision hybrid ceramic angular contact ball bearing. With a 60 mm bore, 95 mm outer diameter, and 18 mm width, this bearing features a 15° contact angle (CD type) and D-type high-capacity design, combined with silicon nitride (Si₃N₄) hybrid ceramic rolling elements (HC) and a phenolic resin cage, factory-preset with Class B medium preload (GB). It integrates ultra-high-speed performance, high load capacity, and flexible arrangement capability into a single package, accommodating radial and unidirectional axial loads simultaneously.

 

The bearing offers a radial dynamic load rating of 43.4 kN and a radial static load rating of 38.0 kN. The GB universal matchable suffix indicates that this bearing features universal matchable (SU) capability – any two bearings of the same model can be directly paired without selective shimming or additional grinding. Users can freely configure them in back-to-back (<>), face-to-face (><), or tandem (>>) arrangements. Manufactured to the P4A super-precision tolerance class with hybrid ceramic technology and Class B medium preload, the bearing achieves a limiting speed of 34,000 r/min. The operating temperature range is -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7012 CDGB/HCP4A

Code Meaning

7012 Basic series designation, 60 mm bore, 95 mm OD

CD 15° contact angle design – offers higher limiting speed and lower heat generation than 25° designs

G Single bearing (not a pre-assembled set)

B Class B medium preload – optimized internal contact stiffness for high-speed heavy-load applications

HC Hybrid ceramic – rolling elements made of bearing-grade silicon nitride (Si₃N₄)

P4A Super-precision tolerance class – dimensional accuracy to ISO P4 class (ABEC 7), running accuracy superior to P4

Core Value: GB universal matchability means every NMT 7012 CDGB/HCP4A bearing's end-face height difference and parallelism are tightly controlled, allowing any two bearings of the same model to be directly paired without selection or re-grinding. The CD-type 15° contact angle generates less frictional heat at equivalent speeds, offering higher limiting speed potential than 25° contact angle designs. The D-type high-capacity design is best suited for heavier loads compared to equivalent B and E type high-speed bearings. HC hybrid ceramic technology drastically reduces centrifugal forces and frictional heat at high speeds. P4A super-precision ensures bore and OD tolerances are controlled within -0.004mm to 0 – these five elements work together to make this bearing a high-performance yet flexible flagship general-purpose precision bearing.

 

Core Performance Advantages

1. Hybrid Ceramic Technology – A Leap in High-Speed Performance

Silicon nitride (Si₃N₄) ceramic balls have only 60% the density of bearing steel, drastically reducing centrifugal forces and frictional heat at high speeds. Ceramic materials also offer lower thermal expansion coefficients and higher elastic modulus, effectively suppressing geometric deformation at high speeds while improving seizure resistance and lubrication-starvation tolerance, extending bearing service life.

 

2. 15° Contact Angle (CD Type) + D-Type High-Capacity Design – Ultra-High Speed and High Load Combined

The 15° small contact angle generates less frictional heat at equivalent speeds, offering higher limiting speed potential than 25° contact angle designs, with a limiting speed of 34,000 r/min. The D-type high-capacity design, with optimized internal geometry and rolling element parameters (ball diameter 11.112 mm, 19 ceramic balls per bearing), is best suited for heavier loads compared to equivalent B and E type high-speed bearings. Combined with a phenolic resin cage, it achieves an outstanding 43.4 kN dynamic and 38.0 kN static load rating. The bearing weighs only 0.373 kg.

 

3. Universal Matchable (GB) – One Inventory, Infinite Arrangements

GB universal matchability delivers outstanding value:

 

Simplified inventory: Stock a single model to cover DB (<>), DF (><), and DT (>>) pairing needs

 

On-site flexibility: Change arrangements during commissioning based on actual load directions

 

Easy maintenance: Replace individual bearings without replacing entire matched sets

 

No shims required: Install directly to achieve design preload

 

4. Class B Medium Preload – Ideal for High-Speed Heavy-Load Applications

Class B medium preload provides "just-right" internal contact stiffness for high-speed spindles – eliminating internal clearance, reducing vibration and noise at high speeds, while providing higher system rigidity than Class A extra light preload, making it particularly suitable for heavy-load high-speed applications requiring greater stiffness.

 

5. P4A Super-Precision Grade – Micron-Level Accuracy

The P4A tolerance class guarantees minimal radial runout and axial play. Bore and outside diameter tolerances are -0.004mm to 0, meeting stringent surface quality and dimensional consistency requirements. Operating temperature range is -30°C to 110°C.

 

6. Lightweight Phenolic Resin Cage

The lightweight high-strength phenolic resin cage provides excellent guidance accuracy and low friction at high speeds, contributing to reduced centrifugal forces, friction, and heat generation – a key factor in achieving the 34,000 r/min limiting speed.

 

7. Clear Performance Specifications

 

Parameter Value

Bore d 60 mm

Outer Diameter D 95 mm

Width B 18 mm

Contact Angle 15°

Dynamic Radial Load 43.4 kN

Static Radial Load 38.0 kN

Ball Diameter Dw 11.112 mm

Balls per Bearing 19

Limiting Speed 34,000 r/min

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Chrome Steel

Cage Material Phenolic

Seal Type Open

Tolerance Class P4A

Preload Class B (Medium)

Arrangement Universal Matchable (SU)

Weight 0.373 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7012 CDGB/HCP4A, with its hybrid ceramic high-speed performance, D-type high-capacity design, and universal matchable flexibility, covers an exceptionally wide range of high-end applications:

 

High-Speed Machine Tool Spindles – CNC machine tools, precision grinders, milling center spindles

 

High-Speed Electric Spindles – high-speed rotary units

 

Machining Center Spindles – vertical/horizontal spindle systems

 

Precision Rotary Tables – high-accuracy rotary positioning

 

Aerospace Components – gyroscopes, actuators, jet engine parts

 

Medical Equipment – high-speed dental drills and medical imaging devices

 

Semiconductor Manufacturing Equipment – precision wafer processing spindles

 

Industrial Robots – high-precision transmission mechanisms and rotary axes

 

Industrial Pumps and Compressors – high-speed rotating machinery

 

Important Installation Notes

✅ This bearing is universally matchable (GB) – any two bearings of the same model can be directly paired.

 

✅ This bearing is open design – select appropriate lubrication method based on application. To achieve the 34,000 r/min limiting speed, oil-air or oil-mist lubrication is recommended.

 

✅ For paired installations, using bearings from the same production batch is recommended for optimal consistency.

 

⚠️ This bearing comes with factory-preset Class B medium preload. No additional preload adjustment is required during installation. However, ensure shaft and housing fits comply with P4A grade requirements (bore/OD tolerance -0.004mm to 0).

 

⚠️ Hybrid ceramic bearings are more sensitive to installation shock. Heat mounting or hydraulic installation methods are recommended – avoid impact on raceways or rolling elements.

 

⚠️ Ensure the contact angle direction matches the intended load direction – incorrect orientation will eliminate load capacity.

 

NMT Quality Commitment

Japan NMT (Enmutī) applies strict Japanese quality standards to every 7012 CDGB/HCP4A bearing – from ring material (high-purity chrome steel), ceramic balls (HIP silicon nitride), to superfinishing processes. End-face height difference, parallelism, and contact angle deviation of each bearing are tightly controlled to ensure universal matchability consistency across any two bearings of the same model. The combination of 15° contact angle (CD type), D-type high-capacity design, hybrid ceramic technology (HC), P4A precision, Class B medium preload, and universal matchable flexibility makes this bearing the flagship general-purpose precision bearing in the NMT 7012 series – offering the perfect balance of high performance, high load capacity, and flexible arrangement.

 

Choose NMT 7012 CDGB/HCP4A for:

 

✅ Hybrid ceramic technology – 34,000 r/min ultra-high-speed performance

 

✅ 15° contact angle + D-type high capacity – 43.4 kN high load capacity

 

✅ Universal matchable – one inventory, infinite arrangements

 

✅ Class B medium preload – ideal for high-speed heavy-load applications

 

✅ P4A super-precision running accuracy

 

✅ Steel rings + ceramic balls – high rigidity, high speed, cost-effectiveness

 

✅ Factory pre-matched – ready to install