Product Overview

The NMT 7013 ACE/HCP4ADT is a pre-assembled duplex tandem matched 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 36 mm (18 mm per row × 2), a 65 mm bore, and a 100 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 phenolic resin cage, factory-preset with 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 7,020 lbf (31.2 kN) and a radial static load rating of 6,525 lbf (29 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 factory preload setting, the set achieves a limiting speed of 24,000 r/min. The set weighs only 0.78 kg with an operating temperature range of -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7013 ACE/HCP4ADT

Code Meaning

7013 Basic series designation, 65 mm bore, 100 mm OD

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

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

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 balances high speed and high load capacity. The E-type 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. 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 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 with preload setting 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 7,020 lbf (31.2 kN) and static radial load rating of 6,525 lbf (29 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 8.731 mm, 25 ceramic balls per bearing), significantly reducing sliding friction and churning losses at high speeds. Compared to equivalent B-type high-speed bearings, the E-type 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 24,000 r/min.

 

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, extending bearing service life. The low density of ceramic balls works synergistically with the lightweight phenolic resin cage to further reduce high-speed rotating mass.

 

4. Factory Pre-Matched with Preload Setting – Ready to Install, Optimal Performance

This bearing set undergoes end-face matching grinding and preload setting at the factory, eliminating the need for additional preload adjustment during installation. The preload configuration enhances overall system rigidity, which is critical for suppressing spindle deflection at high speeds and maintaining machining accuracy. Ready to install out of the box, significantly simplifying the assembly process.

 

5. 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.

 

6. 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 24,000 r/min limiting speed.

 

7. Clear Performance Specifications

 

Parameter Value

Bore d 65 mm

Outer Diameter D 100 mm

Total Width B 36 mm (2×18 mm)

Contact Angle 25°

Dynamic Radial Load 7,020 lbf (31.2 kN)

Static Radial Load 6,525 lbf (29 kN)

Ball Diameter Dw 8.731 mm

Ceramic Balls per Bearing 25

Limiting Speed 24,000 r/min

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Chrome Steel

Cage Material Phenolic Resin

Seal Type Open

Tolerance Class P4A

Arrangement Tandem (<<) DT

Bearings in Set 2

Weight 0.78 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7013 ACE/HCP4ADT 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 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).

 

✅ To achieve the 24,000 r/min limiting speed, oil-air lubrication is recommended. Maximum speed depends on lubrication, mounting fit, and heat dissipation conditions. Please consult NMT technical engineers for application-specific speed recommendations.

 

⚠️ 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 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 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 7013 ACE/HCP4ADT delivers P4A accuracy, ACE-type 25° contact angle, E-type high-speed design, hybrid ceramic technology, tandem-doubled axial capability, and factory preload setting for long-lasting, stable rotational support in your heavy-duty unidirectional-load ultra-high-speed spindles.

 

Choose NMT 7013 ACE/HCP4ADT for:

 

✅ Tandem (DT) arrangement – doubled unidirectional axial capacity

 

✅ ACE-type 25° contact angle + E-type high-speed design – 24,000 r/min ultra-high speed and heavy load combined

 

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

 

✅ Factory pre-matched with preload – ready to install, optimal performance

 

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

 

✅ Lightweight phenolic resin cage

 

✅ 7,020 lbf (31.2 kN) high load capacity

 

✅ Reliable choice for heavy-load ultra-high-speed conditions