Product Overview

The NMT 7014 CD/P4ADBB is a pre-assembled duplex back-to-back matched super-precision all-steel angular contact ball bearing set, comprising 2 rows of bearings precision-paired in a back-to-back (<>) 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 15° contact angle (CD type) and D-type high-capacity design, combined with all-steel rolling elements and a phenolic resin cage, factory-preset with Class B light preload, delivering superior bidirectional axial rigidity, overturning moment resistance, and high load capacity.

 

The bearing set offers a basic dynamic load rating of 83.2 kN and a static load rating of 91.5 kN. The DB back-to-back configuration extends the load action points outward, creating a maximum effective span that provides the highest overturning moment rigidity and bidirectional axial load capacity. Manufactured to the P4A super-precision tolerance class with a 15° contact angle and Class B light preload, the set achieves a limiting speed of 22,000 r/min. The bore and outside diameter matching precision is controlled within -0.004 mm to 0. The set weighs 1.17 kg with an operating temperature range of -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7014 CD/P4ADBB

Code Meaning

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

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

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

DB Duplex Back-to-Back – 2 bearings mounted with contact angles facing outward (<>)

B Class B light preload – ideal for high-speed precision applications

Core Configuration Insight: The DB back-to-back configuration (<>) extends the load action points outward, maximizing the effective span and significantly enhancing spindle resistance to bending moments. The CD-type 15° contact angle generates less frictional heat at equivalent speeds, offering higher limiting speed potential than 25° designs. The D-type high-capacity design, with optimized rolling element parameters – ball diameter 12.7 mm, 19 balls per bearing – achieves an outstanding 83.2 kN dynamic and 91.5 kN static load rating. Class B light preload eliminates internal clearance and reduces vibration and noise at high speeds, while avoiding excessive temperature rise from over-preloading. 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 the flagship precision bearing solution offering the perfect balance of ultimate overturning rigidity, high load capacity, and ultra-precision rotational accuracy. This is a non-universal matchable fixed set – the 2 bearings are factory end-face matched and must not be interchanged or mixed with other bearings.

 

Core Performance Advantages

1. Back-to-Back (DB) Configuration – Ultimate Overturning Rigidity and Bidirectional Load Capacity

The back-to-back (<> ) arrangement orients the contact angles outward in opposite directions, maximizing the effective span and providing the highest overturning moment rigidity. Whether facing axial load direction changes, radial cutting force fluctuations, or bending moment impacts, this configuration delivers the most stable rotational support. The precision-matched pair ensures uniform load distribution across both rows, significantly enhancing overall system rigidity. Dynamic load rating 83.2 kN, static load rating 91.5 kN.

 

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° designs, with a limiting speed of 22,000 r/min. The D-type high-capacity design, with optimized rolling element parameters – ball diameter 12.7 mm, 19 balls per bearing – achieves an outstanding 83.2 kN dynamic and 91.5 kN static load rating. Compared to equivalent B and E type high-speed bearings, the D-type design is best suited for heavier loads.

 

3. Class B Light Preload – Ideal for High-Speed Precision Applications

Class B 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 22,000 r/min limiting speed.

 

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

The P4A tolerance class (surpassing ABEC 7) 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, preventing individual bearing overload, and significantly extending overall set service life. Operating temperature range is -30°C to 110°C.

 

5. 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 22,000 r/min limiting speed.

 

6. 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.

 

7. Open Design – Flexible Lubrication Options

This set features an open design (unsealed), 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.

 

8. Clear Performance Specifications

 

Parameter Value

Bore d 70 mm

Outer Diameter D 110 mm

Total Width B 40 mm (2×20 mm)

Contact Angle 15°

Dynamic Load Rating C 83.2 kN

Static Load Rating C₀ 91.5 kN

Ball Diameter Dw 12.7 mm

Balls per Bearing 19

Limiting Speed 22,000 r/min

Ball Material Chrome Steel

Ring Material Chrome Steel

Cage Material Phenolic Resin

Seal Type Open

Tolerance Class P4A

Preload Class B (Light)

Arrangement Back-to-Back (<> ) DB

Bearings in Set 2

Weight 1.17 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7014 CD/P4ADBB, with its DB back-to-back ultimate overturning rigidity, D-type high-capacity design, 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

 

Industrial Robots – high-precision transmission mechanisms and rotary axes

 

High-Precision Industrial Gearboxes – precision transmission systems

 

Important Installation Notes

⚠️ This is a non-universal matchable fixed set (DB) – the 2 bearings are supplied as one complete unit. Do not interchange or mix with other bearings of the same model.

 

⚠️ The back-to-back configuration (<> ) is directional. Ensure the contact angles face outward to achieve the expected overturning rigidity.

 

✅ This set comes with factory-preset Class B 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).

 

✅ This set is open design – select appropriate lubrication method based on application. To achieve the 22,000 r/min limiting speed, oil-air or oil-mist lubrication is recommended.

 

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

 

⚠️ Ensure shaft and housing bore concentricity and straightness meet P4A grade requirements to achieve the expected rotational accuracy and service life.

 

NMT Quality Commitment

Japan NMT (Enmutī) applies the most stringent end-face matching grinding and preload control to every DB back-to-back 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 CD/P4ADBB delivers P4A accuracy, 15° contact angle ultra-high-speed performance, D-type high-capacity design, DB back-to-back ultimate rigidity, and Class B light preload for unparalleled rotational support in your premier high-speed spindles.

 

Choose NMT 7014 CD/P4ADBB for:

 

✅ DB back-to-back configuration – ultimate overturning rigidity and bidirectional axial load capacity

 

✅ 15° contact angle + D-type high capacity – 83.2 kN high load capacity

 

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

 

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

 

✅ 22,000 r/min ultra-high-speed performance

 

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

 

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

 

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