Product Overview

The NMT 7014 ACE/HCP4AL1DT is a pre-assembled duplex tandem matched (DT) super-precision hybrid ceramic angular contact ball bearing set, comprising 2 rows of bearings precision-paired in a tandem (<<) 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 (ACE type) and high-speed E-type design, combined with silicon nitride (Si₃N₄) hybrid ceramic rolling elements (HC) and a light metal cage (L) , factory-preset with L1 light preload, specifically optimized for ultra-high-speed rotational applications dominated by heavy unidirectional axial loads.

 

The bearing set offers a radial dynamic load rating of 8,190 lbf (36.4 kN) and a static load rating of 7,762 lbf (34.5 kN) . The DT tandem arrangement means both bearings share the same contact angle orientation, with axial loads shared equally across both rows, delivering doubled unidirectional axial load capacity. Manufactured to the P4A super-precision tolerance class with hybrid ceramic technology and L1 light preload, the set achieves a limiting speed of 29,000 r/min. The bore and outside diameter tolerances are controlled within -0.004 mm to 0. The set weighs 1.11 kg with an operating temperature range of -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7014 ACE/HCP4AL1DT

Code Meaning

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

ACE 25° contact angle + High-speed E-type design – 25° contact angle provides superior axial rigidity and radial load capacity; E-type offers higher speed capability and higher load capacity than equivalent B-type designs

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

P4A Super-precision tolerance class – surpassing ABEC 7/ISO P4 standards, running accuracy superior to P4

L1 Light preload – provides optimized rigidity and positioning accuracy while minimizing high-speed friction and heat generation

DT Duplex Tandem – 2 bearings mounted in the same direction (<<) , doubling unidirectional axial load capacity

Core Value: The DT tandem arrangement means both bearings share the same contact angle orientation, with axial loads shared equally across both rows, enabling extreme unidirectional thrust capacity. The ACE-type 25° contact angle + E-type high-speed design balances high speed and high load capacity. HC hybrid ceramic technology drastically reduces centrifugal forces and frictional heat at high speeds. L1 light preload eliminates internal clearance, ensuring precise shaft positioning and minimal deflection. 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 ultimate solution for heavy-load unidirectional ultra-high-speed spindles. 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. Tandem (DT) Arrangement – Doubled Unidirectional Axial Capacity

With both rows oriented identically, axial load capacity increases by nearly 100% compared to a single bearing. With a dynamic radial load rating of 8,190 lbf (36.4 kN) and static radial load rating of 7,762 lbf (34.5 kN) , this set is ideal for heavy-cutting lathe spindles, powerful drilling spindles, and other unidirectional thrust applications. The tandem matched pair ensures consistent preload distribution, enhancing overall system rigidity and load distribution uniformity.

 

2. 25° Contact Angle (ACE Type) + High-Speed E-Type Design – Ultra-High Speed and Heavy Load Combined

The 25° contact angle delivers superior axial rigidity while maintaining ample radial capacity. The E-type high-speed design optimizes internal geometry and rolling element parameters – ball diameter 9.525 mm, 25 ceramic balls per bearing – significantly reducing sliding friction and churning losses at high speeds. Combined with hybrid ceramic rolling elements and a light metal cage (L), the set achieves a limiting speed of 29,000 r/min.

 

3. L1 Light Preload – Ideal for High-Speed Precision Applications

L1 light preload provides precise internal contact stiffness for high-speed spindles – eliminating internal clearance, ensuring precise shaft positioning and minimal deflection, while avoiding excessive temperature rise from over-preloading. This ensures stable temperature performance even at 29,000 r/min limiting speeds.

 

4. 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.

 

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

The P4A tolerance class (surpassing ABEC 7/ISO P4 standards, running accuracy superior to P4) guarantees minimal radial runout and axial play. Bore and outside diameter tolerances are -0.004 mm to 0. Operating temperature range is -30°C to 110°C.

 

6. Light Metal Cage (L) – Speed and Durability Combined

The light metal 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 29,000 r/min limiting speed.

 

7. Open Design – Flexible Lubrication Options

This set features an open design, allowing flexible selection of lubrication methods based on application. The set comes pre-lubricated from the factory – ready to install out of the box.

 

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 25°

Dynamic Radial Load 8,190 lbf (36.4 kN)

Static Radial Load 7,762 lbf (34.5 kN)

Ball Diameter Dw 9.525 mm

Ceramic Balls per Bearing 25

Limiting Speed 29,000 r/min

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Chrome Steel

Cage Material Light Metal (L)

Seal Type Open (Pre-lubricated)

Tolerance Class P4A

Preload Class L1 (Light)

Arrangement Tandem (<<) DT

Bearings in Set 2

Weight 1.11 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7014 ACE/HCP4AL1DT is ideally suited for ultra-high-speed precision equipment where unidirectional axial loads dominate:

 

CNC Lathe Spindles – sustaining continuous axial cutting feed forces

 

Vertical/Horizontal Machining Centers – heavy milling spindles (fixed axial direction)

 

Deep-Hole Drilling Spindles – high-thrust drilling and gun-drilling applications

 

Grinding Machine Wheel Spindles – high-speed rotation under unidirectional grinding forces

 

High-Speed Electric Spindles – precision machining units with constant axial load direction

 

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

 

Important Installation Notes

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

 

⚠️ The tandem arrangement (<<) is directional. Ensure the contact angle direction points toward the incoming axial load – incorrect orientation will eliminate load capacity.

 

✅ This set comes with factory-preset L1 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).

 

✅ To achieve the 29,000 r/min limiting speed, oil-air or oil-mist lubrication is strongly recommended.

 

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

 

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

 

NMT Quality Commitment

Japan NMT (Enmutī) applies stringent end-face parallelism and height-difference matching grinding to every DT tandem set, ensuring load-sharing deviation between the two rows is minimized to an extremely small range. The 7014 ACE/HCP4AL1DT delivers P4A accuracy, ACE-type 25° contact angle, E-type high-speed design, hybrid ceramic technology, L1 light preload, and tandem-doubled axial capability for long-lasting, stable rotational support in your heavy-duty unidirectional-load ultra-high-speed spindles.

 

Choose NMT 7014 ACE/HCP4AL1DT for:

 

✅ Tandem (DT) arrangement – doubled unidirectional axial capacity

 

✅ ACE-type 25° contact angle + E-type high-speed design – 29,000 r/min ultra-high speed and heavy load combined

 

✅ Hybrid ceramic technology – a leap in high-speed performance

 

✅ L1 light preload – ideal for high-speed precision applications

 

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

 

✅ Light metal cage – low friction, high speed

 

✅ 8,190 lbf (36.4 kN) high load capacity

 

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