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2026-08-14

NMT Ltd.
Corporate Communications Department

Japan NMT 7013 CE/HCP4AH1DGA Precision Angular Contact Ball Bearing, 20° Contact Angle Hybrid Ceramic DGA Triple Matched Set P4A Ultra-Precision Machine Tool Motor Spindle Bearing

1 Complete Model & Code Explanation

Model: 7013 CE/HCP4AH1DGA

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

H1: Improved low-friction one-piece solid brass cage with outer ring guidance

DGA: Factory face-ground DGA triple bearings same-direction tandem matched set

Supply form: Three bearings as one DGA matched set with exclusive marking; splitting and separate mixing is forbidden

Comparative Reference Models

20° hybrid ceramic factory DGA triple set: 7013 CE/HCP4AH1DGA

20° hybrid ceramic factory DT twin set: 7013 CE/HCP4ADT

20° hybrid ceramic factory DB twin set: 7013 CE/HCP4ADGB

20° hybrid ceramic single loose bearing H1 cage: 7013 CE/HCP4AH1

20° all steel DGA triple matched set: 7013 CE/P4AH1DGA

15° hybrid ceramic single bearing H1 cage: 7013 CD/HCP4AH1

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 DGA triple same-direction tandem matched set of three units

Rolling element: Silicon nitride Si₃N₄ ceramic balls

Ring material: High-carbon chromium bearing steel, ultra-precision mirror grinding on raceway

Cage: H1 optimized rounded-edge 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: Three 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 DGA triple same-direction tandem matched set

Pairing property: Factory face-ground DGA triple 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. DGA triple tandem arrangement enables all three bearings to bear load in the same direction and greatly improves heavy unidirectional axial load capacity, while its capacity for resisting reverse axial force and overturning moment is inferior to DB / DF 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, excessive vibration and unbalanced preload. The H1 optimized cage adopts streamlined pocket structure, which lowers oil churning loss compared with standard brass cage and achieves better thermal stability under continuous high-speed operation.

2 Structure & Operating Characteristics

Japan NMT 7013 CE/HCP4AH1DGA is premium 7013 series hybrid ceramic DGA triple same-direction tandem matched heavy-duty 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 H1 optimized outer-ring-guided solid brass cage with rounded pocket edges to reduce lubricant agitation friction. 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 DGA triple synchronized face grinding ensures consistent end-face dimension among three bearings for bearing unidirectional heavy axial load after assembly, perfectly suited for long-term heavy unidirectional axial load working conditions. Ceramic balls effectively lower heat generation during prolonged high-speed finishing, and H1 cage further stabilizes temperature under heavy continuous load. Drawback: ceramic rolling elements have limited impact resistance and not suitable for cyclic shock loads. DGA triple layout cannot withstand obvious reverse axial force and large overturning moment. Open structure requires reliable external dust protection on bearing housing. Factory complete set pre-matching eliminates multi-bearing measuring and screening work and reduces assembly cumulative errors of heavy-duty spindles.

3 Core Performance Advantages

1. CE 20° balanced contact angle: Balances limiting speed and axial rigidity with wide adaptability for heavy-duty high-speed milling and form grinding.

2. DGA factory triple same-direction pre-matched set: Synchronized face grinding and controlled pairing tolerance, ready for integral installation without on-site matching errors; axial rigidity and load capacity surpass DT twin set significantly.

3. H1 improved low-friction brass cage: Optimized pocket fillet reduces high-speed oil churning loss, lowers operating temperature and improves stability during continuous high-speed operation.

4. HC silicon nitride ceramic rolling elements: Light weight reduces centrifugal force and suppresses temperature rise; electrical insulation prevents shaft current corrosion inside motor spindles.

5. P4A ultra-precision grade: Strict control of radial and axial runout to maintain stable machining accuracy for heavy-duty CNC equipment.

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 DGA triple matched set and mix with bearings from other batches or models.

5.2 Pairing & Preload Instructions

Supply condition: Three bearings integrated as factory DGA triple matched set with exclusive matching mark; splitting is forbidden.

Layout: Fixed DGA triple same-direction tandem installation.

Reminder: DGA triple combination excels at heavy 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 heavy unidirectional cutting load; heavy preload should be avoided near limiting DN value.

Selection reference:

① Heavy continuous unidirectional heavy axial load, same-direction load layout →7013 CE/HCP4AH1DGA hybrid ceramic DGA triple set

② Medium unidirectional load, twin bearing layout →7013 CE/HCP4ADT hybrid ceramic DT twin set

③ Combined loads, high anti-overturning requirement →7013 CE/HCP4ADGB hybrid ceramic DB twin set

④ Priority on maximum speed, light cutting condition →7013 CE/HCP4AH1 single bearing for on-site matching

⑤ Heavy bidirectional axial load, rigidity first →25° AC contact angle series bearings

⑥ No shaft current risk, cost control →7013 CE/P4AH1DGA all-steel DGA triple 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 and H1 optimized cage balances speed and load capacity, achieving lower operating temperature than standard cage under equivalent working conditions. 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 heavy-load operation to prevent overheating caused by continuous overload. When installing DGA triple 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, monitor temperature rise and vibration step by step. Gradually increase to rated operating speed only after indicators 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, micro-cracks on ceramic balls and abnormal cage abrasion.