Product Overview

The NMT 7009 CE/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 32 mm (16 mm per row × 2), a 45 mm bore, and a 75 mm outer diameter, this set features a 15° contact angle (CE type) , high-speed E-type design, silicon nitride (Si₃N₄) hybrid ceramic rolling elements, and a lightweight phenolic resin cage, specifically optimized for high-speed rotational applications dominated by heavy unidirectional axial loads.

 

The bearing set offers a basic dynamic load rating of 20.8 - 21.06 kN and a static load rating of 17 kN – significantly higher than a single 7009 CE/HCP4A bearing. The tandem arrangement doubles unidirectional axial load capacity by stacking the axial force capability of both rows. The P4A super-precision tolerance class ensures micron-level rotational accuracy at high speeds, with limiting speeds reaching 50,000 r/min under oil-air lubrication.

 

Model Code Decoding – Understanding NMT 7009 CE/HCP4ADT

Code Meaning

7009 Basic series designation, 45 mm bore

CE 15° contact angle + High-speed E-type design – small contact angle provides ultra-high-speed performance; E-type optimizes internal geometry for lower heat generation and higher limiting speeds

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

P4A Super-precision tolerance class – dimensional accuracy P4, running accuracy exceeding P4

DT Duplex Tandem – 2 bearings mounted in the same direction (<<) , factory end-face matched

Critical Feature: The DT tandem arrangement means both bearings share the same contact angle orientation. Axial loads are shared equally across both rows, enabling extreme unidirectional thrust capacity. This matched set does not have a preset internal preload (marked as "not applicable"). Actual operating preload must be adjusted during installation via locknut torque or spacer selection. 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 Arrangement – Doubled Unidirectional Axial Capacity

With both rows oriented identically, axial load capacity increases by nearly 100% compared to a single bearing. The 20.8 - 21.06 kN dynamic rating and 17 kN static rating make this set ideal for heavy-cutting lathe spindles, powerful drilling spindles, and other unidirectional thrust applications.

 

2. 15° Contact Angle + High-Speed E-Type Design – Superior High-Speed Performance

The 15° small contact angle generates less frictional heat at equivalent speeds. Combined with the E-type high-speed design that optimizes internal geometry and ball dimensions, the set achieves a limiting speed of 50,000 r/min under oil-air lubrication. Compared to equivalent B-type high-speed bearings, the E-type design offers higher speed capability and can accommodate heavier loads.

 

3. Hybrid Ceramic Technology – A Leap in High-Speed Performance

Silicon nitride 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.

 

4. Factory Precision Matching – Uniform Load Distribution

Every DT set undergoes end-face matching grinding at the NMT factory, ensuring highly uniform load sharing between the two bearings in tandem installation, preventing individual bearing overload and significantly extending overall set service life.

 

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

The P4A tolerance class guarantees minimal radial runout and axial play. Combined with the low heat generation of the 15° contact angle and 21 balls per bearing, the set maintains stable geometric accuracy and temperature performance at high speeds.

 

6. Lightweight Phenolic Resin Cage

The lightweight high-strength phenolic resin cage provides excellent guidance accuracy and low friction at high speeds, further reducing centrifugal loads and heat generation.

 

7. Clear Performance Specifications

 

Parameter Value

Bore d 45 mm

Outer Diameter D 75 mm

Total Width B 32 mm (2×16 mm)

Contact Angle α 15°

Dynamic Load Rating C 20.8 - 21.06 kN

Static Load Rating C₀ 17 kN

Fatigue Load Limit Pu 0.53 kN

Speed (Oil-Air) 50,000 r/min

Speed (Grease) 32,000 r/min

Ball Diameter Dw 7.144 mm

Balls per Bearing 21

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Bearing Steel

Cage Material Phenolic Resin

Tolerance Class P4A

Arrangement Tandem (<<) DT

Number of Rows 2

Weight 0.423 - 0.47 kg

Carbon Footprint 1.52 kg CO₂e

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7009 CE/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

 

Industrial Pumps/Compressors – unidirectional thrust positioning in high-speed rotating shafts

 

Turbomachinery – high-speed turbine rotor axial positioning

 

Gear Cutting Machines – hobbing and shaping spindles

 

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 does not have a preset internal preload. Actual preload must be controlled during installation via locknut torque or precision spacers. Strictly follow NMT's installation guidelines and recommended torque values.

 

⚠️ To achieve the 50,000 r/min limiting speed, oil-air lubrication is strongly recommended. Grease lubrication limits speed to 32,000 r/min.

 

⚠️ 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 7009 CE/HCP4ADT delivers P4A accuracy, E-type high-speed design, hybrid ceramic technology, and tandem-doubled axial capability for long-lasting, stable rotational support in your heavy-duty unidirectional-load ultra-high-speed spindles.

 

Choose NMT 7009 CE/HCP4ADT for:

 

✅ Tandem arrangement – doubled unidirectional axial capacity

 

✅ 15° contact angle + E-type high-speed design – 50,000 r/min ultra-high-speed performance

 

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

 

✅ P4A super-precision running accuracy

 

✅ Factory precision matched – uniform load distribution

 

✅ Open preload adjustment for flexible application tuning

 

✅ Lightweight phenolic resin cage

 

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