Product Overview

The NMT 7012 FE/HCP4AH1DGA is a pre-assembled duplex universally matchable super-precision hybrid ceramic angular contact ball bearing set, comprising 2 rows of bearings precision-paired in a universal matchable (SU) configuration. With a total width of 36 mm (18 mm per row × 2), a 60 mm bore, and a 95 mm outer diameter, this set features a 25° contact angle and high-speed design, combined with silicon nitride (Si₃N₄) hybrid ceramic rolling elements (HC) and a phenolic resin cage, factory-preset with Class A extra light preload (GA) , and equipped with two lubrication holes on the thrust side of the outer ring (H1) for efficient oil-air lubrication. It integrates ultra-high-speed performance, high load capacity, efficient lubrication, and flexible arrangement capability into a single package, accommodating radial and unidirectional axial loads simultaneously.

 

The bearing set offers a radial dynamic load rating of 37.1 kN and a radial static load rating of 29.0 kN. The DGA universal matchable suffix indicates that this set features universal matchable (SU) capability – any two sets 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 A extra light preload, the set 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 FE/HCP4AH1DGA

Code Meaning

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

F 25° contact angle + high-speed design – 25° contact angle provides superior axial and radial load capacity; F indicates that the inner and outer ring design, dimensions, and internal design have been optimized according to application requirements for lower friction and higher speed

E High-speed design – optimized internal geometry to significantly reduce sliding friction and churning losses at high speeds

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

P4A Super-precision tolerance class – dimensional accuracy to ISO P4 class, running accuracy superior to P4

H1 Two lubrication holes on the thrust side of the outer ring – facilitates oil-air lubrication directly to the rolling contact zone

DGA Duplex General Arrangement – 2-bearing matched set with universal matchable (SU) capability, factory-preset Class A extra light preload

Core Value: DGA universal matchability means every NMT 7012 FE/HCP4AH1DGA 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 25° contact angle + high-speed design offers higher speed capability and can accommodate heavier loads than equivalent B-type designs. HC hybrid ceramic technology drastically reduces centrifugal forces and frictional heat at high speeds. The H1 outer ring lubrication holes facilitate oil-air lubrication directly to the rolling contact zone. P4A super-precision ensures bore and OD tolerances are controlled within -0.004mm to 0 – these five elements work together to make this bearing set a high-performance yet flexible general-purpose precision bearing solution.

 

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. 25° Contact Angle + High-Speed Design – Ultra-High Speed and Heavy Load Combined

The 25° contact angle delivers superior axial rigidity while maintaining ample radial capacity. The high-speed design optimizes internal geometry and rolling element parameters, significantly reducing sliding friction and churning losses at high speeds. Compared to equivalent B-type high-speed bearings, this design offers higher speed capability and can accommodate heavier loads. Combined with hybrid ceramic rolling elements and a phenolic resin cage, the set achieves a limiting speed of 34,000 r/min.

 

3. H1 Outer Ring Lubrication Holes – Maximized Oil-Air Lubrication Efficiency

The H1 suffix indicates two lubrication holes on the thrust side of the outer ring, enabling oil-air lubricant to reach the rolling contact zone directly for maximum lubrication and heat dissipation efficiency. This design ensures stable temperature performance even at 34,000 r/min ultra-high speeds, making it particularly suitable for oil-air lubrication systems.

 

4. Universal Matchable (DGA) – One Inventory, Infinite Arrangements

DGA 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

 

5. High Load Capacity – High Load in Compact Space

With optimized rolling element parameters (ball diameter 7.938 mm, 21 ceramic balls per bearing), it achieves an outstanding 37.1 kN dynamic and 29.0 kN static load rating within a compact 36 mm total width. The set weighs only 0.8 kg.

 

6. Class A Extra Light Preload – Ideal for High-Speed Precision Applications

Class A extra light preload provides "just-right" internal contact stiffness for high-speed spindles – eliminating internal clearance, reducing vibration and noise at high speeds, while avoiding excessive temperature rise from over-preloading. This ensures stable temperature performance even at 34,000 r/min limiting speeds.

 

7. 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.

 

8. 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.

 

9. Clear Performance Specifications

 

Parameter Value

Bore d 60 mm

Outer Diameter D 95 mm

Total Width B 36 mm (2×18 mm)

Contact Angle 25°

Dynamic Radial Load 37.1 kN

Static Radial Load 29.0 kN

Ball Diameter Dw 7.938 mm

Balls per Bearing 21

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 A (Extra Light)

Arrangement Universal Matchable (SU)

Bearings in Set 2

Weight 0.8 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7012 FE/HCP4AH1DGA, with its hybrid ceramic high-speed performance, high-speed design, H1 efficient lubrication, 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

 

High-Frequency Motors – high-speed, high-precision motor applications

 

Important Installation Notes

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

 

✅ This set is open design – select appropriate lubrication method based on application. To achieve the 34,000 r/min limiting speed, oil-air lubrication is strongly recommended, utilizing the H1 outer ring lubrication holes for maximum efficiency.

 

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

 

⚠️ This set comes with factory-preset Class A extra light 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 FE/HCP4AH1DGA bearing set – 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 25° contact angle, high-speed design, hybrid ceramic technology (HC), H1 outer ring lubrication holes, P4A precision, Class A extra light preload, and universal matchable flexibility makes this bearing set the flagship general-purpose precision bearing solution in the NMT 7012 series – offering the perfect balance of high performance, efficient lubrication, and flexible arrangement.

 

Choose NMT 7012 FE/HCP4AH1DGA for:

 

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

 

✅ High-speed design – high speed and heavy load combined

 

✅ H1 outer ring lubrication holes – maximized oil-air lubrication efficiency

 

✅ Universal matchable – one inventory, infinite arrangements

 

✅ 25° contact angle – superior combined radial and axial load capacity

 

✅ Class A extra light preload – ideal for high-speed precision applications

 

✅ P4A super-precision running accuracy

 

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

 

✅ Factory pre-matched – ready to install