1 Complete Model & Code Explanation

Model: 7010 ACE/HCP4AL1DT

Code Definition

7010: Light series precision angular contact ball bearing basic dimension

ACE: 25° contact angle

HC: Hybrid Ceramic (steel rings + silicon nitride ceramic balls)

P4A: Precision tolerance grade P4A

L1: Factory preset light preload grade

DT: Tandem, factory pre-matched tandem set including two bearings

Key Dimensions

Bore d: 50 mm

Outer diameter D: 80 mm

Width B: 16 mm

Contact angle: 25°

Structure: Single row open bearing, two bearings as factory DT matched set

Rolling element: Silicon nitride ceramic ball

Ring material: High-carbon chromium bearing steel

Supply form: Factory pre-matched DT set, do not split and mix with separate bearings

Preload specification: L1 standard light preload, dimension matched before delivery

Pre-filled lubricant: None

Coating: None

Note: Contact SKF for official load ratings and limiting speed data.

Full Product Attributes

Contact form: two-point contact

Number of rows: single row, 2 pcs in DT tandem set

Matching type: Factory pre-tandem matched assembly, no on-site spacer grinding required

Precision class: P4A precision grade

Material: Steel rings + silicon nitride ceramic rolling elements (hybrid ceramic bearing)

Seal: Open type, no seal

Note: The 25° ACE contact angle balances radial stiffness and axial load capacity. Hybrid ceramic design reduces centrifugal force of rolling elements at high speed, lowers temperature rise and prevents electrical corrosion caused by spindle current. L1 light preload preset at factory suits continuous long-term high-speed operation, balancing spindle rigidity and thermal control. DT tandem configuration greatly improves unidirectional axial load capacity, recommended for stable unidirectional axial cutting loads; not suitable for alternating bidirectional thrust. Open construction eliminates seal friction loss and fits oil-air lubrication. No pre-grease, dedicated spindle lubrication system is mandatory. Matched set cannot be split and interchanged with bearings from other batches to prevent unbalanced preload and excessive vibration. Open design provides no dust protection; labyrinth or air curtain dust-proof structure must be equipped on equipment.

2 Structure & Operating Characteristics

Japan NMT 7010 ACE/HCP4AL1DT is size 7010 ultra-high-speed precision hybrid ceramic angular contact ball bearing DT pre-matched set with 25° contact angle. Inner and outer rings undergo ultra-precision grinding; rolling elements adopt high-purity silicon nitride ceramic balls. The factory strictly sorts and matches face height and internal clearance of two bearings according to DT tandem standards with preset L1 light preload. The set can be assembled directly in tandem layout upon arrival without on-site spacer machining.

Ceramic rolling elements have lower mass, generating less heat than all-steel bearings at high speed. Insulation property prevents electrical corrosion. Tandem DT arrangement increases effective rolling elements and greatly enhances unidirectional axial rigidity. Supplied as complete factory matched set, widely used for deep-hole drilling spindles, high-speed grinding spindles under continuous one-side load, heavy-duty unidirectional cutting motor spindles on vertical machining centers.

3 Core Performance Advantages

1. 25° ACE contact angle: Balanced radial stiffness and axial capacity for combined cutting loads.

2. HC hybrid ceramic structure: Light ceramic balls, low temperature rise, anti-electrical insulation, higher DN limit than all-steel bearings.

3. P4A high precision grade: Strict rotary runout control to sustain machining accuracy under long-time high-speed operation.

4. L1 factory preset light preload: Suitable for continuous high-speed conditions, sufficient rigidity with effective overheat suppression.

5. DT factory pre-tandem matched set: Remarkably improved unidirectional axial capacity, simplified assembly without on-site matching.

6. Open unsealed structure: No seal drag loss, fully compatible with oil-air high-speed lubrication.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A hybrid ceramic bearing set must be assembled in dust-free clean environment. Remove all burrs and metal debris from shaft and housing fitting surfaces. Controlled thermal mounting is recommended with temperature strictly limited. Never strike bearing rings or ceramic balls directly. Use complete DT matched set; splitting and mixing with other bearings is prohibited.

5.2 Matching & Preload Instructions

This model is factory DT pre-matched set with L1 light preload. Preload condition is calibrated before delivery; on-site spacer adjustment is generally unnecessary. Test spindle temperature rise and vibration after assembly. Avoid arbitrarily increasing preload under drastically changed load to prevent thermal seizure. DT structure excels only for unidirectional axial loads; switch to DB/DF arrangement for alternating bidirectional thrust.

5.3 Lubrication Matching Solutions

No pre-filled lubricant. Special high-speed spindle grease can be adopted for intermittent high-speed operation. Oil-air forced circulation lubrication is mandatory for long continuous ultra-high-speed running to evacuate friction heat efficiently. Do not mix lubricants of different brands or models; inspect lubrication pipelines regularly.

5.4 Speed Parameter Note

It delivers superior DN limit compared with all-steel DT sets of identical dimension. Maintain sufficient safety margin based on axial load and cooling conditions; reduce maximum speed under sustained heavy load.

6 Daily Maintenance & Fault Troubleshooting

Implement multi-stage low-speed running-in after assembly. Increase speed to rated value only after temperature and vibration stabilize. Open bearings have no built-in dust shield; equipment dust-proof structure cannot be omitted.

Ensure continuous stable lubrication; dry friction operation is forbidden. In case of abnormal temperature rise, noise or sharp vibration growth, sequentially check lubrication supply, assembly coaxial accuracy, axial load level and integrity of dust-proof system, and verify whether bearing preload loses balance.