NMT Ltd.
Corporate Communications Department
Japan NMT 7013 CE/HCP4ADT Precision Angular Contact Ball Bearing, 20° Contact Angle Hybrid Ceramic DT Tandem Matched Set P4A Ultra-Precision Machine Tool Motor Spindle Bearing
1 Complete Model & Code Explanation
Model: 7013 CE/HCP4ADT
Code Definition
7013: Basic outer dimension of 70 series light-duty precision angular contact ball bearing
CE: 20° standard contact angle, balanced limiting speed and axial rigidity, mainstream specification for high-speed cutting
HC: Silicon nitride ceramic rolling elements (hybrid ceramic bearing)
P4A: Ultra-precision grade with tight control of runout and dimensional tolerance
DT: Factory face-ground DT tandem matched set with two bearings
Supply form: Two bearings as one DT matched set; splitting and separate mixing is forbidden
Comparative Reference Models
20° hybrid ceramic factory DT set: 7013 CE/HCP4ADT
20° hybrid ceramic factory DB set: 7013 CE/HCP4ADGB
20° hybrid ceramic single loose bearing: 7013 CE/HCP4A
20° all steel DT matched set: 7013 CE/P4ADT
15° hybrid ceramic outer ring guided single bearing: 7013 CDGB/HCP4A
Core Basic Dimensions
Bore d: 65 mm
Outer diameter D: 100 mm
Width B: 18 mm
Contact angle: 20°
Structure: Single row open non-sealed bearing, factory DT tandem matched set of two units
Rolling element: Silicon nitride Si₃N₄ ceramic balls
Ring material: High-carbon chromium bearing steel, ultra-precision mirror grinding on raceway
Cage: One-piece solid brass cage, outer ring guided
Pre-filled lubricant: None
Surface treatment: Mirror finish for bearing rings, high-precision sorted polishing for ceramic balls
Delivery form: Two bearings packed as matched set with synchronized face grinding; preload spacers sold separately
Note: Official dynamic load rating and limiting DN data can be requested from manufacturer.
Full Product Attributes
Contact form: Two-point contact
Number of rows: Single row, supplied as DT tandem matched pair
Pairing property: Factory face-ground DT set with strictly controlled face height difference. Do not split and match with other bearings.
Precision class: P4A ultra-precision grade
Material: Inner & outer rings of high-carbon chromium bearing steel, rolling elements of silicon nitride ceramic (hybrid ceramic bearing)
Seal structure: Open type, non-sealed
Note: The 20° CE contact angle is a balanced specification. It provides stronger axial rigidity than 15° CD type and higher limiting speed than 25° AC type, suitable for most high-speed finishing conditions. DT tandem arrangement enables both bearings to bear load in the same direction and greatly improves unidirectional axial load capacity, while its capacity for resisting reverse axial force and overturning moment is inferior to DB back-to-back layout. Silicon nitride ceramic rolling elements reduce centrifugal force and temperature rise at high speed. Insulation property prevents raceway electric corrosion caused by shaft current inside built-in motor spindles. Open design is only compatible with oil-air forced lubrication, not suitable for long-term sealed grease operation. Matched set shall not be split arbitrarily; splitting will invalidate pairing accuracy and lead to uneven temperature rise and excessive vibration.
2 Structure & Operating Characteristics
Japan NMT 7013 CE/HCP4ADT is premium 7013 series hybrid ceramic DT tandem matched spindle bearing with 20° contact angle. Inner and outer rings are made of high-carbon chromium bearing steel with stabilized heat treatment and multi-stage aging treatment, equipped with ultra-precision mirror ground raceways. Fitted with outer-ring-guided solid brass cage for uniform pocket load distribution at high rotational speed. Rolling elements adopt high-purity silicon nitride ceramic balls featuring light weight, low friction and inherent insulation.
20° standard contact angle balances rotational speed and load capacity. Factory DT tandem face grinding ensures consistent end-face dimension between two bearings for bearing unidirectional axial load after assembly, perfectly suited for long-term unidirectional heavy axial load working conditions. Ceramic balls effectively lower heat generation during prolonged high-speed finishing. Drawback: ceramic rolling elements have limited impact resistance and not suitable for cyclic shock loads. DT layout cannot withstand obvious reverse axial force and large overturning moment. Open structure requires reliable external dust protection on bearing housing. Factory pre-matching eliminates on-site measuring and screening work and reduces spindle assembly errors.
3 Core Performance Advantages
1. CE 20° balanced contact angle: Balances limiting speed and axial rigidity with wide adaptability for high-speed milling and grinding.
2. DT factory tandem pre-matched set: Synchronized face grinding and controlled pairing tolerance, ready for direct installation without on-site matching errors, doubling unidirectional axial bearing capacity.
3. HC silicon nitride ceramic rolling elements: Light weight reduces centrifugal force and suppresses temperature rise; electrical insulation prevents shaft current corrosion inside motor spindles.
4. P4A ultra-precision grade: Strict control of radial and axial runout to maintain stable machining accuracy for CNC equipment.
5. Outer-ring-guided solid brass cage: Resists deformation under high speed, low vibration and excellent heat conduction for continuous heat dissipation.
6. Open non-sealed structure: Eliminates extra drag heat from sealing components, fully compatible with oil-air forced circulation lubrication system.
5 Assembly Specifications & Usage Guidelines
5.1 Assembly Environment & Operation Standards
P4A hybrid ceramic matched bearings must be assembled in constant-temperature dust-free clean workshops. Remove all burrs and metal debris on shaft and housing mating surfaces. Adopt controlled thermal mounting method with limited heating temperature; open flame heating is prohibited. Avoid striking bearing rings violently; impact may generate invisible cracks on ceramic balls. Never split the matched set and mix with bearings from other batches.
5.2 Pairing & Preload Instructions
Supply condition: Two bearings integrated as factory DT matched set with matching mark; splitting is forbidden.
Layout: Fixed DT tandem installation with identical load direction.
Reminder: DT combination excels at unidirectional axial load. If the working condition contains obvious bidirectional thrust and overturning moment, DB back-to-back set is preferred.
Recommended preload: Light preload for continuous high-speed finishing; standard preload for medium unidirectional cutting load; heavy preload should be avoided near limiting DN value.
Selection reference:
① Continuous unidirectional heavy axial load, same-direction load layout →7013 CE/HCP4ADT hybrid ceramic DT set
② Combined loads, high anti-overturning requirement →7013 CE/HCP4ADGB hybrid ceramic DB set
③ Priority on maximum speed, light cutting condition →7013 CDGB/HCP4A single bearing for on-site matching
④ Heavy bidirectional axial load, rigidity first →25° AC contact angle series bearings
⑤ No shaft current risk, cost control →7013 CE/P4ADT all-steel DT set
5.3 Lubrication Matching Scheme
No pre-filled grease. Oil-air forced circulation lubrication is mandatory for long-term continuous high-speed operation. Synthetic high-speed spindle grease can only be applied temporarily for short commissioning. Install high-precision filters in lubrication pipeline to maintain oil cleanliness. Hard contaminants cause raceway scratches and ceramic ball damage. Do not mix different brands or types of lubricants.
5.4 Speed Parameter Note
20° CE contact angle combined with ceramic balls realizes balanced speed and load capacity. Ceramic rolling elements cannot withstand impact loads; shock conditions must be avoided during operation. Complete cooling system and sufficient speed safety margin are required for long-duration full-speed operation to prevent overheating caused by continuous overload. When installing DT tandem set, ensure load direction aligns with bearing contact angle force direction; reverse load is forbidden.
6 Daily Maintenance & Fault Troubleshooting
Carry out multi-stage low-speed running-in after assembly. Gradually increase to rated operating speed only after temperature rise and vibration stay stable. Open bearings have no built-in dust shield; reliable external dust sealing must be installed on bearing housing.
Supply clean lubricant continuously to avoid dry friction damage caused by oil starvation. In case of continuous abnormal noise, overheating or sharp vibration growth, inspect sequentially: lubricant cleanliness, preload magnitude, assembly coaxiality, whether matched set is split and mixed, external impact and overload, reverse axial load. Monitor bearing temperature regularly to detect early failure signs including raceway fatigue and micro-cracks on ceramic balls.