Product Overview

The NMT 7013 CD/HCP4AQBCC is a pre-assembled quadruplex QBC matched super-precision hybrid ceramic angular contact ball bearing set, comprising 4 rows of bearings precision-paired in a tandem-back-to-back-tandem (<<>>) QBC configuration. With a total width of 72 mm (18 mm per row × 4), a 65 mm bore, and a 100 mm outer diameter, this set features a 15° contact angle (CD type) and D-type high-capacity design, combined with silicon nitride (Si₃N₄) hybrid ceramic rolling elements (HC) and a phenolic resin cage, factory-preset with Class C moderate preload, delivering ultimate bidirectional axial rigidity, overturning moment resistance, and high load capacity.

 

The bearing set offers a radial dynamic load rating of 111 kN (24,975 lbf) and a static load rating of 150 kN (33,750 lbf). The QBC (tandem-back-to-back-tandem) configuration provides the highest system rigidity and bidirectional axial load capacity. Manufactured to the P4A super-precision tolerance class with a 15° contact angle and Class C moderate preload, the set achieves a limiting speed of 36,000 r/min. The bore and outside diameters of the bearings are matched to within a maximum of one-third of the permitted diameter tolerance, ensuring highly uniform load distribution across all 4 rows. The set weighs 1.44 – 1.45 kg with an operating temperature range of -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 7013 CD/HCP4AQBCC

Code Meaning

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

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

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

P4A Super-precision tolerance class – bore and OD tolerances -0.004 mm to 0

QBC Quadruplex QBC arrangement (Quadruplex Back-to-Back-Cascade) – 4 bearings arranged in tandem-back-to-back-tandem (<<>>) configuration

C Class C moderate preload – optimized internal contact stiffness for high-speed heavy-load applications

Core Configuration Insight: The QBC (<<>>) configuration consists of 4 bearing rows – the center two in back-to-back (<> ) providing maximum overturning rigidity, with one tandem (>>) row on each side doubling unidirectional axial load capacity. This represents the highest rigidity and highest load capacity configuration available in angular contact bearing arrangements. This is a non-universal matchable fixed set – the 4 bearings are factory end-face matched, with bore and OD matching precision controlled within one-third of the allowable tolerance, and must not be interchanged or mixed with other bearings.

 

Core Performance Advantages

1. QBC Quadruplex Configuration – Ultimate System Rigidity and Bidirectional Axial Load Capacity

The QBC (<<>>) configuration combines the dual advantages of back-to-back (<> ) and tandem (>>) arrangements:

 

Center two rows back-to-back: Provides maximum overturning moment rigidity, effectively resisting bending and eccentric loads

 

One tandem row on each side: Doubles unidirectional axial load capacity on each side, with symmetric layout achieving perfect bidirectional axial load balance

 

Dynamic load rating 111 kN (24,975 lbf) , static load rating 150 kN (33,750 lbf)

 

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° contact angle designs. The D-type high-capacity design, with optimized rolling element parameters – ball diameter 11.112 mm, 20 ceramic balls per bearing – achieves an outstanding 111 kN dynamic and 150 kN static load rating.

 

3. Hybrid Ceramic Technology – Speed and Durability Combined

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, significantly extending maintenance intervals.

 

4. 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. This ensures stable temperature performance even at 36,000 r/min limiting speeds.

 

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

The P4A tolerance class (ABEC 7) guarantees minimal radial runout and axial play. All 4 bearings undergo factory precision end-face matching grinding, with bore and OD matching precision controlled within one-third of the allowable tolerance, ensuring highly uniform load distribution across all rows, preventing individual bearing overload, and significantly extending overall set service life. 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, while its low mass further reduces centrifugal loads – a key factor in achieving the 36,000 r/min limiting speed.

 

7. Steel Rings + Ceramic Balls – High Rigidity, High Speed, Cost-Effectiveness

Premium chrome steel rings combined with silicon nitride ceramic balls deliver the high rigidity and impact resistance of all-steel bearings along with the high-speed low-heat characteristics of hybrid ceramic technology. This combination offers significant cost advantages over full ceramic bearings while maintaining superior performance.

 

8. Clear Performance Specifications

 

Parameter Value

Bore d 65 mm

Outer Diameter D 100 mm

Total Width B 72 mm (4×18 mm)

Contact Angle 15°

Dynamic Radial Load 111 kN (24,975 lbf)

Static Radial Load 150 kN (33,750 lbf)

Ball Diameter Dw 11.112 mm

Ceramic Balls per Bearing 20

Limiting Speed 36,000 r/min

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Chrome Steel

Cage Material Phenolic Resin

Seal Type Open

Tolerance Class P4A (ABEC 7)

Preload Class C (Moderate)

Arrangement QBC (<<>>)

Bearings in Set 4

Weight 1.44 – 1.45 kg

Temperature Range -30°C to 110°C

Typical Applications

The NMT 7013 CD/HCP4AQBCC is engineered for premium precision equipment demanding ultimate system rigidity, high load capacity, and uncompromising accuracy:

 

Heavy-Duty Vertical/Horizontal Machining Center Spindles – powerful milling and heavy boring spindles

 

High-Rigidity 5-Axis Machining Centers – complex surface machining, aerospace structural component processing

 

Heavy-Duty CNC Turning Centers – large-depth, high-feed turning spindles

 

Precision Grinding Machine Wheel Spindles – high-accuracy internal/external grinding, jig grinders

 

Gear Cutting Machines – hobbing, shaping, milling, and grinding spindles

 

Large Mold Machining Centers – high-rigidity spindles for combined roughing and finishing

 

Aerospace Component Machining Equipment – high-speed heavy cutting of titanium and superalloys

 

Semiconductor Manufacturing Equipment – high-precision wafer processing spindles

 

Industrial Robots – high-precision transmission mechanisms and rotary axes

 

Important Installation Notes

⚠️ This is a non-universal matchable fixed set (QBC) – the 4 bearings are supplied as one complete unit. Do not interchange or mix with other bearings of the same model.

 

⚠️ The QBC (<<>>) configuration is strictly directional. Installation must strictly follow NMT's assembly drawings to ensure correct contact angle orientation for each row. Incorrect orientation will completely eliminate load capacity.

 

✅ 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).

 

✅ Bore and OD matching precision is controlled within one-third of the allowable tolerance – ensure shaft and housing bore concentricity and straightness meet P4A grade requirements.

 

✅ To achieve the 36,000 r/min limiting speed, oil-air or oil-mist lubrication is recommended. Maximum speed depends on lubrication, mounting fit, and heat dissipation conditions. Please consult NMT technical engineers for application-specific speed recommendations.

 

⚠️ Total width is 72 mm. Ensure sufficient axial installation space.

 

⚠️ 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 the most stringent end-face matching grinding and preload control to every QBC quadruplex bearing set. All 4 bearings undergo complete factory matching and full-parameter inspection, with bore and OD matching precision controlled within one-third of the allowable tolerance, ensuring load-sharing deviation between rows is minimized to an extremely small range. The 7013 CD/HCP4AQBCC delivers P4A accuracy, 15° contact angle ultra-high-speed performance, D-type high-capacity design, hybrid ceramic technology, and QBC quadruplex ultimate rigidity for unparalleled rotational support in your premier heavy-duty high-speed spindles.

 

Choose NMT 7013 CD/HCP4AQBCC for:

 

✅ QBC quadruplex configuration – ultimate system rigidity and bidirectional load capacity

 

✅ 15° contact angle + D-type high capacity – 111 kN high load capacity

 

✅ Hybrid ceramic technology – speed and durability together

 

✅ Class C moderate preload – ideal for high-speed heavy-load applications

 

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

 

✅ 36,000 r/min ultra-high-speed performance

 

✅ Steel rings + ceramic balls – high rigidity, high speed, cost-effectiveness

 

✅ Factory pre-matched – matching precision within one-third of tolerance