1 Complete Model & Code Explanation

Model: 7013 ACD/P4A

Code Definition

7013: Light series precision angular contact ball bearing basic dimension

ACD: 25° heavy-duty contact angle, high axial rigidity and load capacity with moderate limiting speed

P4A: P4A ultra-precision grade

Note: C(15° high speed)＜AC(18° balanced)＜ACD(25° heavy load); standard all-steel bearing without ceramic, coating or advanced sorting grade; Comparative extended models:7013 ACD/HCP4A (hybrid ceramic),7013 ACD/P4AH1DGA (H1 coated GA selected ceramic version)

Key Dimensions

Bore d: 65 mm

Outer diameter D: 100 mm

Width B: 18 mm

Contact angle: 25°

Structure: Single row open bearing, supplied as single standard unit

Rolling element: High-carbon chromium bearing steel ball

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

Supply form: Single independent bearing, DB/DF/DT arrangement configurable on site

Pre-filled lubricant: None

Surface treatment: Standard mirror finish without functional coating

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: standard unit, freely combinable DB/DF/DT on site

Precision class: P4A ultra-precision grade

Material: All-steel angular contact ball bearing

Seal: Open type, no seal

Note: The 25° ACD large contact angle delivers prominent axial stiffness and anti-tilting moment, preferred for continuous heavy cutting. Load capacity improves compared with 18° AC model while limiting DN speed decreases. Standard all-steel structure without insulation, not suitable for built-in motor spindles with shaft current. Optimized for belt-driven spindles. Without raceway coating, suitable for stable working conditions, clean lubrication and low start-stop impact in mass-production machines.

Open structure eliminates seal drag; continuous oil-air lubrication is recommended. High-speed spindle grease can be adopted for intermittent operation. No built-in dust shield; labyrinth or air curtain dust-proof structure must be equipped.

2 Structure & Operating Characteristics

Japan NMT 7013 ACD/P4A is size 7013 all-steel P4A ultra-precision single angular contact ball bearing. All components are manufactured from high-carbon chromium bearing steel with mirror ultra-precision grinding on raceways and balls. The 25° ACD contact angle maximizes axial load capacity focusing on rigidity and heavy-duty performance.

Designed for belt-driven vertical machining centers, mold engraving & milling machines, grinder spindles. Suitable for general precision machine tools without inverter shaft current, long-term heavy milling and cost-sensitive applications.

3 Core Performance Advantages

1. 25° ACD heavy-duty contact angle: Excellent axial load capacity and anti-tilting rigidity, suitable for continuous heavy cutting and high-feed machining.

2. P4A ultra-precision grade: High rotational accuracy to control spindle radial and axial runout and guarantee workpiece precision.

3. All-steel standard construction: Mature and stable, short lead time and outstanding overall cost performance.

4. Open non-sealed design: No friction heat generated by sealing, fully compatible with oil-air lubrication for long continuous operation.

5. Flexible matching solution: Single bearings can be assembled into DB back-to-back, DF face-to-face, DT tandem configurations with different preload levels.

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A ultra-precision bearing shall be assembled in constant-temperature dust-free clean workshop. Remove all burrs, dust and metal debris on shaft and housing mating surfaces. Adopt controlled thermal mounting with limited heating temperature; open flame heating is forbidden. Never strike the bearing to avoid raceway damage and ball indentation. Bearings from the same batch are preferred for paired assembly to guarantee consistent face height.

5.2 Matching & Preload Instructions

Supplied as standard all-steel single bearings without factory pre-matching; DB back-to-back, DF face-to-face, DT tandem layout can be arranged on site. Medium preload is recommended for continuous heavy milling; light preload for light-load finishing. Avoid heavy preload running at maximum speed for long periods to prevent excessive temperature rise.

Selection guide: ①Pure high-speed light cutting →15° C series; ②Balanced general medium load →18° AC series; ③Continuous heavy cutting, rigidity priority →7013 ACD/P4A; ④Built-in spindle requiring anti-electric corrosion →corresponding HC hybrid ceramic version.

5.3 Lubrication Matching Solutions

No pre-filled lubricant. Oil-air forced circulation lubrication is recommended for long continuous high-speed operation. Special high-speed spindle grease is only allowed for short intermittent machining. Install filters on oil circuit to maintain lubricant cleanliness; hard contaminants easily cause raceway scuffing. Do not mix lubricants of different brands or specifications.

5.4 Speed Parameter Note

Limiting DN speed is lower than 18° AC and 15° C series. Reserve sufficient speed safety margin under continuous heavy load; long-term operation near limiting speed is not advised.

6 Daily Maintenance & Fault Troubleshooting

Carry out multi-stage low-speed running-in after assembly; gradually increase to rated speed only after temperature rise and vibration stabilize. Open bearings have no built-in dust shield; front spindle dust sealing cannot be omitted.

Maintain continuous supply of clean lubricant to prevent dry friction caused by oil shortage. In case of abnormal heating, continuous noise or sudden vibration change, inspect sequentially: oil supply & lubricant cleanliness, over-limit preload, assembly coaxial accuracy, dust seal condition, cutting load impact. For all-steel bearings, strictly monitor lubricant cleanliness to prevent raceway fatigue pitting.