Product Overview

The NMT 7014 ACD/HCP4ADGA 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 40 mm (20 mm per row × 2), a 70 mm bore, and a 110 mm outer diameter, this set features a 25° contact angle (AC 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 A extra light preload (GA) . It integrates ultra-high load capacity, high-speed performance, 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 79.3 kN (17,827 lbf) and a static load rating of 86.5 kN (19,445 lbf) . 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, providing effective load sharing within a predetermined preload range. 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 maximum speed of 36,000 r/min. The set weighs 1.0 – 1.05 kg with an operating temperature range of -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7014 ACD/HCP4ADGA

Code Meaning

7014 Basic series designation, 70 mm bore (14×5 mm), 110 mm OD

AC Angular contact design with 25° contact angle

D D-type high-capacity design – best suited for heavier loads compared to equivalent B and E type high-speed bearings

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

P4A Super-precision tolerance class – surpassing ABEC 7/ISO P4 standards, bore and OD tolerances -0.004 mm to 0

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 (SU) means every NMT 7014 ACD/HCP4ADGA 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 AC-type 25° contact angle delivers superior axial rigidity and radial load capacity. The D-type high-capacity design is best suited for heavier loads compared to equivalent B and E type designs. 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 -0.004 mm to 0 – these five elements work together to make this bearing set a high-capacity, high-speed, and flexible flagship precision bearing solution.

 

Core Performance Advantages

1. Duplex Universal Matchable Set – Doubled System Rigidity and Load Capacity

This bearing set comprises 2 rows of bearings precision-matched into one unit, delivering double the load capacity and system rigidity. The universal matchable (SU) feature allows flexible configuration in back-to-back (<>), face-to-face (><), or tandem (>>) arrangements – one inventory, infinite arrangements. Both bearings undergo factory end-face matching grinding, ensuring uniform load distribution across both rows, preventing individual bearing overload, and significantly extending overall set service life. Dynamic load rating 79.3 kN (17,827 lbf) , static load rating 86.5 kN (19,445 lbf) .

 

2. 25° Contact Angle + D-Type High-Capacity Design – Powerful Combined Load Capacity

The 25° contact angle delivers superior axial rigidity while maintaining ample radial capacity. The D-type high-capacity design, with optimized rolling element parameters – ball diameter 12.7 mm, 19 ceramic balls per bearing – is best suited for heavier loads compared to equivalent B and E type high-speed bearings. This set is specifically designed for high load capacity and relatively high speed operation.

 

3. 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, significantly extending bearing service life.

 

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. 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 the 36,000 r/min maximum speed.

 

6. P4A Super-Precision Grade – Micron-Level Spindle Accuracy

The P4A tolerance class (surpassing ABEC 7/ISO P4 standards) guarantees minimal radial runout and axial play. Bore and outside diameter tolerances are -0.004 mm to 0. Both bearings undergo factory precision end-face matching grinding, ensuring highly uniform load distribution across both rows. Operating temperature range is -30°C to 110°C.

 

7. 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 36,000 r/min maximum speed.

 

8. Open Design – Flexible Lubrication Options

This set features an open design, allowing flexible selection of lubrication methods based on application requirements, and facilitating easy maintenance and relubrication.

 

9. Clear Performance Specifications

 

Parameter Value

Bore d 70 mm

Outer Diameter D 110 mm

Total Width B 40 mm (2×20 mm)

Contact Angle 25°

Dynamic Radial Load 79.3 kN (17,827 lbf)

Static Radial Load 86.5 kN (19,445 lbf)

Ball Diameter Dw 12.7 mm

Ceramic Balls per Bearing 19

Maximum Speed 36,000 r/min

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Chrome Steel

Cage Material Phenolic Resin

Seal Type Open

Tolerance Class P4A

Preload Class A (Extra Light)

Arrangement Universal Matchable (SU)

Bearings in Set 2

Weight 1.0 – 1.05 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7014 ACD/HCP4ADGA, with its duplex universal matchable ultimate rigidity, hybrid ceramic high-speed performance, and P4A super-precision grade, 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

 

High-Precision Industrial Gearboxes – precision transmission systems

 

Pumps and Compressors – high-speed rotating machinery

 

Aerospace Components – gyroscopes, actuators, jet engine parts

 

Semiconductor Manufacturing Equipment – precision wafer processing spindles

 

Industrial Robots – high-precision transmission mechanisms and rotary axes

 

Important Installation Notes

⚠️ This is a duplex fixed matched set – the 2 bearings are supplied as one complete unit. Do not separate or mix with other bearings of the same model.

 

✅ This set features universal matchable (SU) capability – freely configurable as back-to-back (<>), face-to-face (><), or tandem (>>) arrangements.

 

✅ This set is open design – select appropriate lubrication method based on application. To achieve the 36,000 r/min maximum speed, oil-air or oil-mist lubrication is recommended.

 

⚠️ 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 -0.004 mm 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.

 

✅ This set comes pre-lubricated from the factory – ready to install out of the box.

 

NMT Quality Commitment

Japan NMT (Enmutī) applies the most stringent end-face matching grinding and preload control to every DGA duplex bearing set. Both bearings undergo complete factory matching and full-parameter inspection, ensuring load-sharing deviation between rows is minimized to an extremely small range. The 7014 ACD/HCP4ADGA delivers P4A accuracy, 25° contact angle high rigidity, D-type high-capacity design, hybrid ceramic technology, Class A extra light preload, and universal matchable flexibility for unparalleled rotational support in your premier high-speed spindles.

 

Choose NMT 7014 ACD/HCP4ADGA for:

 

✅ Duplex universal matchable set – doubled system rigidity and load capacity

 

✅ 25° contact angle + D-type high capacity – 79.3 kN (17,827 lbf) high load capacity

 

✅ Hybrid ceramic technology – 36,000 r/min ultra-high-speed performance

 

✅ Universal matchable – one inventory, infinite arrangements

 

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

 

✅ P4A super-precision running accuracy – bore/OD tolerance -0.004 mm to 0

 

✅ Phenolic resin cage – low friction, low noise, high speed

 

✅ Factory pre-matched and pre-lubricated – ready to install