1 Complete Model & Code Explanation

Model: 7012 CD/HCP4AQBCA

Code Definition

7012: Light series precision angular contact ball bearing basic dimension

CD: 15° contact angle, small contact angle design for ultra-high limiting speed

HC: Hybrid Ceramic construction; inner/outer rings: high carbon chromium bearing steel, rolling elements: silicon nitride Si₃N₄ ceramic balls

P4AQBCA: P4A ultra-precision grade + QB premium single sorting

QB: Premium Single Sorting, each bearing individually inspected for face height and clearance, ready for flexible on-site matching

Note: CD(15° high speed)＜CE(18° balanced)＜ACE(25° heavy axial load); QB = single selected unit for field assembly; QBB = factory pre-matched set; HC means hybrid ceramic insulated type, no HC stands for all steel bearing

Key Dimensions

Bore d: 60 mm

Outer diameter D: 95 mm

Width B: 18 mm

Contact angle: 15°

Structure: Single row open bearing, supplied as single QB selected unit

Rolling element: Silicon nitride Si₃N₄ ceramic ball

Ring material: High-carbon chromium bearing steel

Supply form: Single QB selected bearing, customers can assemble DB/DF/DT arrangement on site according to demands

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 single bearing

Matching mode: Individually QB sorted unit, flexible for on-site DB/DF/DT combination

Precision class: P4A ultra-precision grade

Material: Hybrid ceramic bearing (steel rings + silicon nitride ceramic rolling elements)

Seal: Open type, no seal

Note: The 15° CD small contact angle reduces rolling resistance and delivers much higher limiting DN speed than 18° CE and 25° ACE variants, suitable for long-term high-speed light & medium load applications, while axial rigidity and overturn resistance are lower than large contact angle series.

HC hybrid ceramic configuration provides insulation capability to block shaft current and prevent electric corrosion on built-in motor spindles. Lighter ceramic balls lower centrifugal force and improve high-speed thermal stability. Ceramic rolling elements have weaker impact resistance; knocking and shock loads must be avoided during assembly.

QB premium sorting means each bearing is independently screened on face height and clearance. Users can flexibly configure back-to-back DB, face-to-face DF or tandem DT layout, more flexible than fixed factory pre-matched QBB sets. Open structure eliminates seal drag; continuous oil-air lubrication is mandatory. Long-term high-speed operation with grease is not suggested. No built-in dust shield; labyrinth or air curtain dust-proof device must be equipped.

2 Structure & Operating Characteristics

Japan NMT 7012 CD/HCP4AQBCA is size 7012 ultra-precision hybrid ceramic single angular contact ball bearing with 15° contact angle and QB premium sorting. Inner/outer rings adopt ultra-precision mirror ground high-carbon chromium bearing steel, rolling elements are high-purity silicon nitride ceramic balls. Every single bearing is independently sorted to control face height and clearance range for stable batch consistency.

The 15° small contact angle geometry generates less heat under high-speed rotation with superior limiting speed performance. Insulated lightweight ceramic balls effectively solve shaft current issues of built-in motor spindles and realize lower operating temperature. Widely adopted on high-speed engraving milling machines and high-speed machining center spindles pursuing maximum rotational speed.

3 Core Performance Advantages

1. 15° CD small contact angle: Low friction loss, excellent limiting DN speed, ideal for continuous high-speed operation.

2. HC hybrid ceramic construction: Silicon nitride balls offer insulation against shaft current corrosion; light weight reduces centrifugal effect and optimizes temperature rise control.

3. P4A precision + QB single sorting: Strict independent dimension screening for each unit, enabling flexible DB/DF/DT matching on site.

4. Open unsealed structure: Eliminates seal friction loss, complies with design standards of high-speed spindles adopting oil-air lubrication.

5. Flexible assembly scheme: Free quantity procurement, various matching layouts available according to load characteristics.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4AQBCA ultra-precision hybrid ceramic bearing should be assembled in constant-temperature dust-free clean environment. Remove all burrs, dust and metal debris on shaft and housing mating surfaces. Use controlled thermal mounting; never strike the bearing, especially avoid impact on ceramic rolling elements, shock may induce micro-cracks and premature failure. Assemble bearings from the same production batch preferentially.

5.2 Matching & Preload Instructions

Supplied as independent QB selected single bearings without fixed pairing relation; DB, DF, DT arrangement can be configured on site. Select layout based on spindle speed and load; light preload is recommended for high-speed applications, accurately adjusted via spacers. ⚠️Heavy preload is forbidden under ultra-high speed conditions to prevent thermal seizure.

Selection guide: ①Heavy cutting requiring high axial rigidity →7012 ACE series; ②Balanced speed & load →7012 CE series; ③No insulation demand, cost control →7012 CD/P4AQBCA all steel QB version; ④Ready-to-use factory matched set →7012 CD/HCP4AQBB.

5.3 Lubrication Matching Solutions

No pre-filled lubricant. Oil-air forced circulation lubrication is mandatory for long continuous high-speed operation. Special high-speed spindle grease is only allowed for short intermittent low-speed operation. Install high-precision filters on oil circuit and strictly control lubricant cleanliness; do not mix lubricants of different brands. Ceramic bearings demand higher lubrication cleanliness than all steel bearings to avoid hard contaminants entering raceways.

5.4 Speed Parameter Note

Limit DN value is obviously higher than 18° CE and 25° ACE bearings of same size. Reserve extra speed safety margin under continuous heavy load; properly reduce rated operating speed under long-term high temperature.

6 Daily Maintenance & Fault Troubleshooting

Carry out multi-stage low-speed extended running-in after assembly; gradually raise to working speed only after temperature and vibration stay stable. Open bearings have no built-in dust shield; front spindle dust sealing cannot be omitted.

Maintain continuous supply of clean lubricant and avoid dry friction without oil. In case of abnormal heating, continuous noise or sharp vibration increase, sequentially check: oil supply & cleanliness, excessive preload, assembly coaxiality, dust seal integrity, cutting overload and abnormal shaft current.