1 Complete Model & Code Explanation

Model: 7013 ACDGC/HCP4AL

Code Definition

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

ACD: 25° contact angle, excellent axial rigidity and high anti-tilting moment

GC: Upgraded reinforced large ball structure with modified raceway contact profile to balance heavy load capacity and high-speed performance

HC: Hybrid Ceramic, silicon nitride Si₃N₄ ceramic rolling elements, insulated against electrocorrosion, low density and low centrifugal force

P4AL: Long-term stabilized P4A precision grade, optimized dimensional stability and geometric tolerance for continuous long-time high-speed operation

Supply form: Independent single bearing without factory pairing marks, supports on-site DB/DF/DT pairing, no matched spacer included

Comparative Reference Models

All-steel standard single: 7013 ACD/P4A

All-steel basic large ball: 7013 ACDGA/P4A

All-steel reinforced large ball: 7013 ACDGB/P4A

Hybrid ceramic upgraded reinforced large ball: 7013 ACDGC/HCP4AL

Factory pre-matched assembly: 7013 ACDGC/HCP4AL-DBC / QBC series

Core Basic Dimensions

Bore d: 65 mm

Outer diameter D: 100 mm

Width B: 18 mm

Contact angle: 25°

Structure: Single row open type single bearing without seal

Rolling element: Silicon nitride Si₃N₄ ceramic ball with GC enlarged dimension

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

Pre-filled lubricant: None

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

Delivery form: Individually packed single unit, spacer excluded

Note: Official dynamic load rating and limiting DN value data can be requested from manufacturer.

Full Product Attributes

Contact form: Two-point contact

Number of rows: Single row

Pairing property: Loose single unit without factory pairing mark, supports flexible on-site DB/DF/DT combination

Precision class: P4AL long-term optimized ultra-precision grade

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

Seal structure: Open type, non-sealed

Note: ACDGC/HCP4AL is high-end hybrid ceramic model. GC raceway profile balances heavy impact load and high-speed capability. Ceramic rolling elements isolate shaft current to prevent electrocorrosion commonly seen in built-in motor spindles. Compared with same-size all-steel bearings, lower centrifugal force at high speed brings less heat generation and higher limiting DN speed. Open design fits oil-air lubrication. Supplied as single bearing. Spindle manufacturers need to purchase spacers separately, conduct face height sorting and preload adjustment, and cannot directly replace factory pre-matched sets. It is mainly applied to built-in motor spindles, also suitable for high-end belt-driven spindles pursuing high rotating speed and low heat rise.

2 Structure & Operating Characteristics

Japan NMT 7013 ACDGC/HCP4AL retains standard 7013 mounting dimensions, adopting GC modified raceway plus silicon nitride ceramic rolling elements. Inner and outer rings are made of high-carbon chromium bearing steel with stabilized heat treatment, aging treatment and multi-stage ultra-precision mirror grinding. Ceramic balls are manufactured from high-purity silicon nitride with precise polishing and strict dimensional grouping.

Compared with ACDGB all-steel bearings, ceramic balls feature much lower weight, which greatly reduces centrifugal load during high-speed rotation, lowers raceway contact pressure and restrains temperature rise. The insulation property of ceramic blocks shaft current to avoid electric pitting on raceways and balls. GC improved raceway contour optimizes contact ellipse and prevents edge stress concentration, realizing good capacity for heavy cutting load and stability under prolonged high-speed operation. Single-unit supply provides flexible layout freedom for spindle designers.

3 Core Performance Advantages

1. GC upgraded large-ball optimized raceway: Balances heavy load capacity and high-speed adaptability, improves contact stress distribution and resists intermittent cutting impact.

2. HC silicon nitride hybrid ceramic balls: Insulated anti-electrocorrosion for built-in motor spindles; low density reduces high-speed centrifugal force, outstanding temperature control and higher limiting DN than all-steel bearings of same size.

3. 25° ACD contact angle: Sufficient axial load capacity and strong anti-tilting performance, suitable for mold machining and multi-direction alternating load conditions.

4. P4AL long-term precision grade: Optimized dimensional stability for 24-hour continuous mass production equipment.

5. Open non-sealed structure: Eliminates sealing drag heat, fully compatible with oil-air forced circulation lubrication system.

6. Independent single-unit supply: No bundled spacers; manufacturers can freely select DB/DF/DT arrangement and independently design spacers & preload schemes.

4 Main Application Fields

4.1 Built-in motor spindle units

High-speed machining centers and engraving-milling motor spindles with shaft current risk requiring anti-electrocorrosion bearings.

4.2 High-end high-speed belt-driven spindles

Precision mold machine tools pursuing maximum rotating speed and low temperature rise while bearing medium-heavy cutting loads.

4.3 Spindles of high-speed precision internal & external grinders and high-speed gear finishing machines

Long-duration continuous high-speed precision machining scenarios.

4.4 R&D of high-end spindle modules with independent bearing pairing and preload commissioning

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4AL ultra-precision hybrid ceramic bearings shall be assembled in constant-temperature dust-free clean workshops. Fully remove burrs, metal debris and dust on shaft and housing mating surfaces. Adopt controlled thermal mounting with strict temperature limit; open flame heating is prohibited. Never strike inner or outer ring directly. Ceramic balls are brittle and prone to invisible cracks under impact.

This is independent single bearing. When multiple bearings are assembled in series or back-to-back, face height screening and matching must be completed on site. Random mixing assembly is forbidden, which will lead to uneven load, local overheating and abnormal vibration.

5.2 Pairing & Preload Instructions

Supplied as independent single unit without pairing marks or attached spacers.

Optional layout: DB back-to-back, DF face-to-face, DT tandem.

Light preload recommended for high-speed light-load finishing; medium preload for balancing high speed and moderate cutting load. Avoid heavy preload under long-time maximum rotating speed.

Selection reference:

① No shaft current demand, priority on heavy load cost performance →7013 ACDGB/P4A (all steel)

② Built-in motor spindle requiring insulation anti-electrocorrosion, high speed priority →7013 ACDGC/HCP4AL

③ Factory pre-matched complete set needed →7013 ACDGC/HCP4AL-DBC / QBC series

5.3 Lubrication Matching Scheme

No pre-filled lubricant. Oil-air forced circulation lubrication is preferred for long continuous high-speed operation. Fully synthetic high-speed spindle grease can only be used for short intermittent processing. Equip lubrication circuit with high-precision filter to maintain medium cleanliness; hard particles will create indentations on ceramic balls and raceways. Do not mix lubricants of different brands.

5.4 Speed Parameter Note

Hybrid ceramic structure greatly enhances limiting DN capacity. GC design maintains strong load capacity, yet sufficient speed safety margin should be reserved under continuous heavy load. Although ceramics resist high temperature, excessive temperature accelerates lubricant aging; continuous spindle temperature monitoring is recommended.

6 Daily Maintenance & Fault Troubleshooting

Carry out multi-stage low-speed running-in after assembly. Do not raise speed to rated working level until temperature rise and vibration stay stable. Open bearing has no built-in dust shield; labyrinth seal or air curtain dust-proof structure must be installed at spindle front end.

Maintain continuous supply of clean lubricant to avoid dry friction caused by oil starvation. In case of continuous abnormal noise, overheating and sudden vibration, inspect sequentially: oil supply system & lubricant cleanliness, bearing pairing accuracy, preload value, assembly coaxiality, shaft current leakage and external cutting impact load. Monitor temperature regularly to detect early signs of contact fatigue and electrocorrosion.