1 Complete Model & Code Explanation

Model: 7013 ACE/HCP4ADT

Code Definition

7013: Basic outer dimension of 70 series light-duty precision angular contact ball bearing

ACE: 20° contact angle optimized for high speed, outstanding radial rigidity with moderate axial load capacity

HC: Hybrid Ceramic, silicon nitride Si₃N₄ ceramic rolling elements, insulated anti-electrocorrosion, low mass and low centrifugal force at high speed

P4A: Ultra-precision grade with tightly controlled runout and dimensional tolerance

DT: Factory Tandem Match. Two bearings pre-sorted by face height and supplied as a matched tandem set for tandem mounting

Supply form: Set of two bearings for DT tandem arrangement, factory pre-matched with matching mark. Do not split and randomly combine with other bearings.

Comparative Reference Models

25° contact single hybrid ceramic: 7013 ACDGC/HCP4AL

20° contact single hybrid ceramic: 7013 ACE/HC P4A

20° contact hybrid ceramic DB back-to-back set: 7013 ACE/HCP4ADB

20° contact hybrid ceramic DT tandem set: 7013 ACE/HCP4ADT

Core Basic Dimensions

Bore d: 65 mm

Outer diameter D: 100 mm

Single bearing width B: 18 mm

Contact angle: 20°

Structure: Single row open bearing, two-piece DT matched set

Rolling element: High-purity silicon nitride Si₃N₄ ceramic balls

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

Pre-filled lubricant: None

Surface treatment: Mirror finish for rings, ultra-high precision polishing for ceramic balls, no extra functional coating

Delivery form: Two bearings bound with matching serial mark, spacers not included

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 (two bearings as DT tandem set)

Pairing property: Factory pre-matched DT tandem set with unique matching label; cannot be separated and mixed

Precision class: P4A ultra-precision grade

Material: Bearing steel inner/outer rings + silicon nitride ceramic balls (hybrid ceramic bearing)

Seal structure: Open type, non-sealed

Note: ACE 20° contact angle is designed for high-speed applications. It delivers higher limiting speed and lower heat generation compared with 25° ACD series, with slightly reduced axial load capacity. Equipped with HC ceramic balls to solve electrocorrosion caused by shaft current in built-in motor spindles. DT tandem structure supports large unidirectional axial load, commonly used for rear spindle support. This factory matched set has strictly controlled face height difference. On-site height sorting is unnecessary once installed as DT tandem. Matching accuracy will be invalid if split. Open design is suitable for oil-air lubrication, not recommended for long-term grease sealed operation.

2 Structure & Operating Characteristics

Japan NMT 7013 ACE/HCP4ADT adopts standard 7013 mounting dimensions, ACE 20° high-speed contact angle and silicon nitride ceramic rolling elements supplied as DT matched set. Inner and outer rings are manufactured from high-carbon chromium bearing steel with stabilized heat treatment, multi-stage aging and ultra-precision mirror grinding. Silicon nitride balls go through strict dimensional grouping and high-grade polishing to satisfy high-speed spindle requirements.

Compared with 25° contact angle bearings, the 20° ACE design reduces axial component force and friction loss at high speed, expanding available limiting DN range. Insulating ceramic balls block shaft current and prevent electric pitting on raceways. Lower mass reduces centrifugal load and suppresses temperature rise during continuous high-speed operation. Factory DT pre-matching ensures consistent height difference between two bearings for even load distribution and less vibration, simplifying assembly for spindle manufacturers.

3 Core Performance Advantages

1. ACE 20° high-speed optimized contact angle: Lower friction loss, higher limiting speed and better temperature control than 25° contact angle series, suitable for continuous high-speed light & medium cutting.

2. HC silicon nitride hybrid ceramic balls: Insulated against electrocorrosion for built-in motor spindles; low density reduces high-speed centrifugal force with excellent thermal stability.

3. P4A ultra-precision grade: Strict control of radial and axial runout to maintain long-term rotational accuracy.

4. Factory pre-matched DT tandem set: Face dimension sorting completed in factory, direct on-site assembly without manual height screening and achieves uniform load distribution.

5. Open non-sealed design: Eliminates seal drag heat, fully compatible with oil-air forced circulation lubrication.

6. DT tandem load feature: Able to withstand large unidirectional axial load, ideal for rear support bearing layout of spindles.

4 Main Application Fields

4.1 Rear support unit of built-in high-speed motor spindles

High-speed engraving & milling motor spindles, compact high-speed machining center spindles with shaft current risk, prioritizing high speed and low temperature rise.

4.2 Spindles of high-speed PCB engravers and precision compact high-speed grinders

Long-term high-speed machining under moderate unidirectional axial load.

4.3 Mass production of standardized spindle modules for machine builders requiring ready-to-install matched bearing sets.

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 with limited heating temperature; open flame heating is prohibited. Never strike bearing rings directly. Ceramic balls are brittle and prone to invisible internal cracks under impact.

⚠️Important reminder: The two DT bearings carry unified matching serial numbers. Do not separate and mix with other bearings; matching precision will be permanently lost.

5.2 Pairing & Preload Instructions

Supply condition: Two bearings pre-matched for DT same-direction tandem mounting to carry unidirectional axial load.

Layout extension: DT+DB combination is available for bidirectional load; this set cannot be used directly for DB/DF installation.

Recommended preload: Light preload preferred for high-speed finishing; medium preload acceptable for moderate cutting loads. Avoid heavy preload running continuously at maximum speed.

Selection reference:

① Heavy cutting and large axial load → choose ACD 25° contact angle series

② High speed priority, built-in motor spindle, unidirectional axial load →7013 ACE/HCP4ADT (DT set)

③ Back-to-back bidirectional support required →7013 ACE/HCP4ADB matched set

5.3 Lubrication Matching Scheme

No pre-filled lubricant. Oil-air circulation lubrication is mandatory for long continuous high-speed operation. High-speed fully synthetic spindle grease can only be used temporarily for short intermittent commissioning. Install high-precision filter in lubrication pipeline to keep media clean; hard particles will scratch ceramic balls and raceways. Do not mix lubricants of different brands.

5.4 Speed Parameter Note

20° ACE contact angle plus hybrid ceramic delivers excellent limiting DN performance. Nevertheless, DT tandem arrangement generates slightly higher heat density than single bearing. Complete cooling and stable lubrication supply are required for continuous full-speed operation with sufficient speed safety margin.

6 Daily Maintenance & Fault Troubleshooting

Carry out multi-stage low-speed running-in after assembly. Do not raise speed to rated value until temperature rise and vibration remain stable. Open bearings have no built-in dust shield; dust protection must be arranged on rear bearing housing.

Maintain continuous supply of clean lubricant to avoid dry friction caused by oil starvation. In case of abnormal noise, overheating or sharp vibration increase, inspect sequentially: lubricant cleanliness, preload setting, assembly coaxiality, shaft current leakage and axial cutting impact load. Monitor bearing operating temperature regularly to detect early electrocorrosion and contact fatigue symptoms.