1 Complete Model & Code Explanation

Model: 7012 CDGB/HCP4A

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

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

HC: Hybrid Ceramic, silicon nitride ceramic balls + steel inner & outer rings

P4A: P4A ultra-precision grade

Note: CD(15° high speed)＜CE(18° balanced)＜ACE(25° heavy axial load); GB = single selected unit for field assembly; DBB = 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 GB selected unit

Rolling element: Silicon nitride (Si₃N₄) ceramic ball

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

Supply form: Single GB 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 GB 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 combination of 15° CD small contact angle and ceramic balls greatly reduces rotational inertia, delivering much higher limiting DN speed and lower heat generation than equivalent all-steel bearings, suitable for long-term ultra-high-speed light & medium load applications. Axial rigidity and overturn resistance are inferior to large contact angle ACE series.

Ceramic rolling elements provide electrical insulation to block shaft current and prevent electric pitting corrosion on raceways, making it the preferred choice for built-in motor spindles.

GB 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 DBB sets. Open structure eliminates seal drag; continuous oil-air lubrication is mandatory. Long-term high-speed operation with grease is not recommended. No built-in dust shield; labyrinth or air curtain dust-proof device must be equipped.

2 Structure & Operating Characteristics

Japan NMT 7012 CDGB/HCP4A is size 7012 ultra-precision hybrid ceramic single angular contact ball bearing with 15° contact angle and GB premium sorting. Inner/outer rings are mirror-finished high-carbon chromium bearing steel; rolling elements adopt silicon nitride ceramic balls. Every single bearing is independently sorted to control face height and clearance range for stable batch consistency.

15° small contact angle matched with ceramic balls features low rotational inertia, low temperature rise and higher limiting speed, with insulation against electric corrosion. Widely adopted on built-in motor spindles and high-speed engraving milling spindles to resolve bearing electric erosion caused by variable frequency drive.

3 Core Performance Advantages

1. 15° CD small contact angle + ceramic rolling elements: Low rotational inertia, low friction heat, limiting DN speed far higher than all-steel bearings of the same dimension.

2. HC hybrid ceramic insulation: Isolates shaft current and prevents electric pitting to extend service life for motor spindles.

3. P4A ultra-precision grade: Superior dimensional and rotational accuracy to minimize spindle runout at high RPM.

4. GB single sorting + open construction: Freely combinable DB/DF/DT; eliminates seal friction loss, ideal for oil-air lubricated ultra-high-speed spindles.

5. Excellent ceramic material properties: High hardness, good self-lubrication and wear resistance, improved fatigue life under high-speed working conditions.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A hybrid ceramic ultra-precision bearing shall be assembled in constant-temperature dust-free clean environment. Remove all burrs, dust and metal debris on shaft and housing mating surfaces. Adopt controlled thermal mounting with limited heating temperature; avoid direct high-temperature baking on ceramic balls. Never strike the bearing; impact may cause ceramic ball cracking and permanent raceway damage. Assemble bearings from the same production batch preferentially.

5.2 Matching & Preload Instructions

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

Selection guide: ①Belt-driven spindle without shaft current & cost sensitive →all steel 7012 CDGA/P4A; ②Continuous high-temperature machining environment →high-temperature series 7012 CDGATP/P4B; ③Heavy cutting requiring high axial rigidity →7012 ACE series; ④Ready-to-use factory matched set →7012 CD/HC P4A DBB.

5.3 Lubrication Matching Solutions

No pre-filled lubricant. Oil-air forced circulation lubrication is mandatory for long continuous ultra-high-speed operation. Special high-speed spindle grease is only allowed for short intermittent low-speed operation. Install high-precision filters on oil circuit to guarantee lubricant cleanliness; hard impurities will lead to surface chipping of ceramic balls. Do not mix lubricants of different brands.

5.4 Speed Parameter Note

Limit DN value is significantly higher than all-steel bearings of the same model. Even with good heat resistance of ceramics, sufficient safety speed margin must be reserved under continuous heavy load; avoid prolonged operation near limiting speed.

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 & lubricant cleanliness, excessive preload, assembly coaxiality, dust seal integrity and cutting overload; focus on lubricant impurity control to protect ceramic rolling elements.