Product Overview

The NMT 7014 ACD/P4ADGC is a pre-assembled duplex universally matchable super-precision all-steel 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 all-steel rolling elements and a cotton fabric reinforced phenolic cage, factory-preset with Class C moderate preload (DGC) . It integrates high load capacity, excellent speed performance, Class C moderate-preload high rigidity, 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 79.1 – 79.3 kN (17,803 – 17,842 lbf) and a static load rating of 86.5 kN (19,462 lbf) . The DGC 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 Class C moderate preload, the set achieves a limiting speed of 29,000 r/min. The set weighs 1.19 kg with an operating temperature range of -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7014 ACD/P4ADGC

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

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

DGC Duplex General Arrangement + Class C preload – 2-bearing matched set with universal matchable (SU) capability, factory-preset Class C moderate preload

Core Value: DGC universal matchability (SU) means every NMT 7014 ACD/P4ADGC 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, providing effective load sharing within a predetermined preload range. The AC-type 25° contact angle delivers superior axial rigidity and radial load capacity. The D-type high-capacity design, with optimized rolling element parameters – ball diameter 12.7 mm, 19 balls per bearing – achieves outstanding load capacity. Class C moderate preload provides the optimal balance between high-speed capability and system rigidity. 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, Class C moderate-preload high-rigidity, 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. 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 79.1 – 79.3 kN (17,803 – 17,842 lbf) , static load rating 86.5 kN (19,462 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 balls per bearing – is best suited for heavier loads compared to equivalent B and E type high-speed bearings.

 

3. Class C Moderate Preload – Ideal for High-Speed Heavy-Load Applications

Class C moderate 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. Preload force is 1,188 N with axial stiffness of 314 N/µm, offering excellent stability for high-precision applications. This ensures stable temperature performance even at the 29,000 r/min limiting speed.

 

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

DGC 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. 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.

 

6. Cotton Fabric Reinforced Phenolic Cage – Speed and Durability Combined

The cotton fabric reinforced phenolic cage, outer ring centred, features excellent sliding properties and high-speed adaptability. It 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 29,000 r/min limiting speed.

 

7. All-Steel Construction – High Rigidity, Impact Resistance, Cost-Effectiveness

Premium chrome steel rings and balls offer higher fracture toughness and impact resistance – more reliable under interrupted cutting and accidental overload conditions. All-steel bearings also offer significant cost advantages for high-volume industrial applications.

 

8. Open Design – Flexible Lubrication Options

This set features an open design, allowing flexible selection of lubrication methods based on application requirements – grease lubrication for general applications, oil-air or oil-mist lubrication for high-speed heavy-load conditions.

 

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 79.1 – 79.3 kN (17,803 – 17,842 lbf)

Static Radial Load 86.5 kN (19,462 lbf)

Ball Diameter Dw 12.7 mm

Balls per Bearing 19

Limiting Speed 29,000 r/min

Preload Force (Class C) 1,188 N

Axial Stiffness (Class C) 314 N/µm

Ball Material Chrome Steel

Ring Material Chrome Steel

Cage Material Cotton Fabric Reinforced Phenolic

Seal Type Open

Tolerance Class P4A

Preload Class C (Moderate)

Arrangement Universal Matchable (SU)

Bearings in Set 2

Weight 1.19 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7014 ACD/P4ADGC, with its duplex universal matchable rigidity, D-type high-capacity design, Class C moderate preload, 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

 

Aerospace Components – gyroscopes, actuators, jet engine parts

 

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

 

Semiconductor Manufacturing Equipment – precision wafer processing spindles

 

High-Precision Industrial Gearboxes – precision transmission systems

 

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

 

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 29,000 r/min limiting speed, oil-air or oil-mist lubrication is recommended.

 

⚠️ This set comes with factory-preset Class C moderate 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).

 

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

 

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

 

NMT Quality Commitment

Japan NMT (Enmutī) applies the most stringent end-face matching grinding and preload control to every DGC 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/P4ADGC delivers P4A accuracy, 25° contact angle high rigidity, D-type high-capacity design, Class C moderate preload (1,188 N / 314 N/µm), and universal matchable flexibility for unparalleled rotational support in your premier high-speed spindles.

 

Choose NMT 7014 ACD/P4ADGC for:

 

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

 

✅ 25° contact angle + D-type high capacity – 79.3 kN (17,842 lbf) high load capacity

 

✅ Class C moderate preload – 1,188 N preload force / 314 N/µm axial stiffness

 

✅ Universal matchable – one inventory, infinite arrangements

 

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

 

✅ 29,000 r/min ultra-high-speed performance

 

✅ Cotton fabric reinforced phenolic cage – low friction, low noise, high speed

 

✅ All-steel – high rigidity, impact resistance, cost-effectiveness

 

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