Product Overview

The NMT 71901 CE/HCP4A is an open, single-row super-precision hybrid ceramic angular contact ball bearing. With a 12 mm bore, 24 mm outer diameter, and 6 mm width, this bearing is the ultra-compact member of the 719 series. Featuring a 15° contact angle (CE type) and high-speed E-type design, combined with silicon nitride (Si₃N₄) hybrid ceramic rolling elements (HC) and a phenolic resin cage, it integrates ultra-high speed, extreme lightweight, and super-precision rotational accuracy into a single package, accommodating radial and unidirectional axial loads simultaneously.

 

The bearing offers a basic dynamic load rating of 2.16 kN and a static load rating of 0.88 kN. Manufactured to the P4A super-precision tolerance class with a 15° contact angle and hybrid ceramic technology, the bearing achieves a limiting speed of 109,000 r/min under grease lubrication and 165,000 r/min under oil-air lubrication – one of the highest speed ratings in the precision bearing industry. The bearing weighs only 0.01 kg (10 g) with a carbon footprint of just 0.04 kg CO₂e, making it the ultimate choice for extreme lightweight and ultra-high-speed applications. The operating temperature range is -30°C to 110°C.

 

Model Code Decoding – Understanding NMT 71901 CE/HCP4A

Code Meaning

71901 Basic series designation, 12 mm bore, 24 mm OD, 6 mm width – 719 series ultra-thin design

CE 15° contact angle + High-speed E-type design – 15° small contact angle offers extremely high limiting speed potential and minimal heat generation; E-type optimizes internal geometry for higher speed capability than equivalent B-type designs

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

P4A Super-precision tolerance class – superior to ABEC 7, running accuracy superior to P4

Core Value: The CE-type 15° contact angle + E-type high-speed design generates minimal frictional heat at equivalent speeds, offering extremely high limiting speed potential (oil-air lubrication 165,000 r/min). HC hybrid ceramic technology drastically reduces centrifugal forces and frictional heat at ultra-high speeds. P4A super-precision ensures bore and OD tolerances are controlled within -0.004 mm to 0 – these four elements work together to make this bearing the ultimate precision bearing solution for miniature ultra-high-speed spindles.

 

Core Performance Advantages

1. 165,000 r/min Ultra-High Speed – Industry-Leading Performance

This bearing achieves a limiting speed of 165,000 r/min under oil-air lubrication and 109,000 r/min under grease lubrication. This speed level makes it the ideal choice for ultra-high-speed miniature spindles in PCB drilling machines, dental handpieces, and high-speed engraving machines. The synergy between the 15° contact angle and E-type high-speed design ensures stable operation and low heat generation at extreme speeds.

 

2. Hybrid Ceramic Technology – The Foundation of Ultra-High-Speed Performance

Silicon nitride (Si₃N₄) ceramic balls have only 60% the density of bearing steel, drastically reducing centrifugal forces and frictional heat at the 165,000 r/min limiting speed. Ceramic materials also offer lower thermal expansion coefficients and higher elastic modulus, effectively suppressing geometric deformation at ultra-high speeds while providing excellent electrical insulation and extended service life. Combined with chrome steel rings, this achieves the perfect balance of high rigidity, ultra-high speed, and durability.

 

3. 15° Contact Angle (CE Type) + High-Speed E-Type Design – The Perfect Union of Ultra-High-Speed Performance

The 15° small contact angle generates less frictional heat at equivalent speeds, offering higher limiting speed potential than 25° designs. The E-type high-speed design optimizes internal geometry and rolling element parameters – ball diameter 3.175 mm, 11 ceramic balls per bearing – significantly reducing sliding friction and churning losses at high speeds. Compared to equivalent B-type designs, the E-type design offers higher speed capability.

 

4. Extreme Lightweight – Only 10 Grams

The bearing weighs only 0.01 kg (10 g) with a carbon footprint of just 0.04 kg CO₂e. The extremely low rotating mass effectively reduces centrifugal loads and inertia moments at high speeds, making it the ideal choice for miniaturized, lightweight designs.

 

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

The P4A tolerance class (superior to ABEC 7) guarantees minimal radial runout and axial play. Bore and outside diameter tolerances are -0.004 mm 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 ultra-high speeds. This material offers an excellent strength-to-weight ratio, contributing to reduced centrifugal forces, friction, and heat generation – a key factor in achieving the 165,000 r/min limiting speed.

 

7. Open Design – Flexible Lubrication Options

This bearing features an open design, allowing flexible selection of lubrication methods based on application – grease lubrication for general ultra-high-speed applications (109,000 r/min), oil-air lubrication for extreme ultra-high-speed machining (165,000 r/min).

 

8. Clear Performance Specifications

 

Parameter Value

Bore d 12 mm

Outer Diameter D 24 mm

Width B 6 mm

Contact Angle 15°

Dynamic Load Rating C 2.16 kN

Static Load Rating C₀ 0.88 kN

Ball Diameter Dw 3.175 mm

Ceramic Balls per Bearing 11

Speed (Grease) 109,000 r/min

Speed (Oil-Air) 165,000 r/min

Distance to Pressure Point a 5.2 mm

Ball Material Silicon Nitride (Si₃N₄)

Ring Material Chrome Steel

Cage Material Phenolic Resin

Seal Type Open

Tolerance Class P4A

Arrangement Non-Universal Matchable

Weight 0.01 kg (10 g)

Carbon Footprint 0.04 kg CO₂e

Temperature Range -30°C to 110°C

Typical Applications

The NMT 71901 CE/HCP4A, with its 165,000 r/min ultra-high speed and extreme lightweight design, covers an exceptionally wide range of cutting-edge miniature ultra-high-speed applications:

 

PCB Drilling Machine Spindles – high-speed micro-hole drilling for printed circuit boards

 

Dental Handpieces – high-speed dental turbine handpieces

 

High-Speed Engraving/Milling Machines – micro-precision mold and jewelry processing

 

Micro-Machining Electric Spindles – micro-milling, micro-drilling

 

Optical Scanning Devices – high-speed rotating mirrors, laser scanning

 

Medical Surgical Power Tools – high-speed orthopedic drills, micro-surgical instruments

 

Semiconductor Manufacturing Equipment – wafer dicing, chip packaging

 

Aerospace Micro-Components – gyroscopes, micro-actuators

 

Industrial Robots – micro high-speed rotary joints

 

Important Installation Notes

✅ This is a single-row open design bearing – select appropriate lubrication method based on application: grease lubrication for general ultra-high-speed applications (limiting speed 109,000 r/min), oil-air lubrication for extreme ultra-high-speed machining (limiting speed 165,000 r/min).

 

✅ This is a non-universal matchable single bearing (no G/GA suffix). For paired configurations (DB, DF, DT arrangements), please order the corresponding pre-matched set.

 

⚠️ Ensure shaft and housing fits comply with P4A grade requirements (bore/OD tolerance -0.004 mm to 0) to achieve the expected rotational accuracy and service life.

 

⚠️ A single-row angular contact ball bearing can accommodate axial load in one direction only. Radial loads generate an additional axial force that must be counteracted through paired mounting.

 

⚠️ This bearing has no preload setting – preload must be adjusted during paired installation based on the specific configuration.

 

⚠️ Hybrid ceramic bearings are more sensitive to installation shock. Heat mounting or hydraulic installation methods are recommended – avoid impact on raceways or rolling elements. Due to the extremely small size, extra care is required during installation to avoid excessive force.

 

✅ Installation in a clean environment is recommended to prevent contaminant ingress that could affect ultra-high-speed performance.

 

NMT Quality Commitment

Japan NMT (Enmutī) applies strict Japanese quality standards to every 71901 CE/HCP4A bearing – from ring material (high-purity chrome steel), ceramic balls (HIP silicon nitride), to superfinishing processes. The combination of 15° contact angle (CE type), E-type high-speed design, hybrid ceramic technology (HC), P4A super-precision, and phenolic resin cage makes this bearing the flagship miniature precision bearing in the NMT 719 series – offering the perfect balance of ultra-high speed, extreme lightweight, and ultra-precision performance.

 

Choose NMT 71901 CE/HCP4A for:

 

✅ 165,000 r/min oil-air lubrication limiting speed – industry-leading

 

✅ Hybrid ceramic technology – the foundation of ultra-high-speed performance

 

✅ Extreme lightweight – only 10 g, carbon footprint 0.04 kg CO₂e

 

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

 

✅ 15° contact angle + E-type high-speed design – ultra-high speed and low heat combined

 

✅ Lightweight phenolic resin cage – low friction, low noise, high speed

 

✅ Open design – flexible lubrication options

 

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