1 Complete Model & Code Explanation

Model: 7013 ACDGA/P4A

Code Definition

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

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

GA: Optimized large-diameter ball internal design, higher load capacity and structural rigidity compared with standard configuration

P4A: P4A ultra-precision grade

Supply form: Independent single bearing, not factory pre-matched set, multiple units can be freely combined for pairing

Comparative reference models:

Standard ball single bearing: 7013 ACD/P4A

Large ball single bearing: 7013 ACDGA/P4A

Hybrid ceramic large ball version: 7013 ACDGA/HC/P4A

Factory DB matched assembly: 7013 ACDGA/P4ADBA / 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: High-carbon chromium bearing steel, GA version equipped with enlarged balls

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

Pre-filled lubricant: None

Surface treatment: Mirror finish for inner ring, outer ring and balls, no functional coating

Delivery form: Individually packed single unit, no matched spacer included

Note: Official data of dynamic load rating and limiting DN value 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 on-site DB/DF/DT pairing

Precision class: P4A ultra-precision grade

Material: All-steel angular contact ball bearing

Seal structure: Open type, non-sealed

Note: The ACDGA large ball version adopts larger rolling elements under identical outer dimensions, raising basic dynamic & static load rating and better impact resistance than standard 7013 ACD. The 25° contact angle provides outstanding axial load and anti-tilting performance, suitable for intermittent cutting impact and medium to heavy cutting conditions. Open structure avoids friction heat caused by sealing, optimized for oil-air lubrication. This product is supplied as single bearing. If double or triple bearing spindle configuration is required, machine builders need to select spacers separately and complete height sorting and preload adjustment. It cannot replace factory pre-matched bearing sets. No insulation treatment, not applicable for built-in motor spindles generating shaft current, recommended for belt-driven spindle units.

2 Structure & Operating Characteristics

Japan NMT 7013 ACDGA/P4A keeps standard 7013 outer dimensions, equipped with GA optimized large-diameter ball structure internally. Inner and outer rings are manufactured from premium high-carbon chromium bearing steel, subjected to stabilized heat treatment and multiple ultra-precision mirror grinding processes. Raceway surface quality and geometric precision satisfy application requirements of high-end machine tool spindles.

Compared with standard ACD bearings of the same size, GA large ball design expands contact bearing area, improves overall rigidity and impact resistance, delivering longer service life under interrupted milling and impact loads in mold machining. Open non-sealed design reduces high-speed drag loss, suitable for long continuous high-speed operation. Supplied as single unit, offering greater flexibility for spindle manufacturers to design double-row, triple-row or multi-row bearing layout according to rigidity demands.

3 Core Performance Advantages

1. GA optimized large ball internal structure: Higher load capacity and structural rigidity than standard 7013 ACD bearing under equal outer size, stronger resistance against cutting impact.

2. 25° ACD contact angle: Excellent axial load capacity and anti-tilting moment, ideal for mold machining and heavy cutting.

3. P4A ultra-precision grade: Strictly controlled radial and axial rotational runout to guarantee dimensional stability in precision machining.

4. Open non-sealed design: Eliminate sealing friction loss, lower temperature rise, fully compatible with oil-air forced lubrication system.

5. Flexible single-unit supply: No bundled matching spacer, machine tool manufacturers can freely select DB/DF/DT arrangement and independently design spacers & preload scheme.

6. Mature all-steel material solution: Stable supply chain and controllable lead time, convenient for standardized bulk stocking of spindle manufacturers.

4 Main Application Fields

4.1 Belt-driven spindle units of vertical machining centers and CNC mold engraving & milling machines

Medium-heavy milling and intermittent cutting conditions, spindle manufacturers independently design double/triple bearing layout.

4.2 Spindles of high-precision internal & external grinders and small gear finishing equipment

Applications requiring high rigidity and anti-tilting capacity for medium-long term continuous precision machining.

4.3 R&D and standardized spindle module assembly for spindle equipment manufacturers with independent bearing pairing & commissioning

5 Assembly Specifications & Usage Guidelines

5.1 Assembly Environment & Operation Standards

P4A ultra-precision bearings should be assembled in constant-temperature dust-free clean workshop. Fully remove burrs, metal debris and dust on shaft and housing mating surfaces. Adopt controlled thermal mounting with temperature strictly regulated; open flame heating is forbidden. Never strike inner or outer ring directly to prevent raceway indentation.

This item is single bearing. When multiple bearings work together, height sorting and matching must be completed on site. Random mixing will lead to uneven load distribution, abnormal vibration and temperature rise.

5.2 Pairing & Preload Instructions

Supplied as independent single unit without pairing marks or spacers.

Arrangement options: DB back-to-back, DF face-to-face, DT tandem configuration.

Medium preload recommended for continuous heavy cutting; light preload for light-load finishing. Avoid long-time full-speed operation under heavy preload.

Selection reference:

① Priority on load capacity and impact resistance →7013 ACDGA/P4A

② General stable cutting with cost priority →7013 ACD/P4A

③ Factory DB pre-matched complete set with spacer →7013 ACDGA/P4ADBC, 7013 ACDGA/P4AQBC series

④ Anti-electrocorrosion for motor spindles →7013 ACDGA/HC/P4A hybrid ceramic bearing

5.3 Lubrication Matching Scheme

No pre-filled lubricant. Oil-air forced circulation lubrication is preferred for long continuous high-speed operation. High-speed spindle grease can only be used for short intermittent processing. Install precision filter on lubrication circuit to maintain oil cleanliness; hard particles easily cause raceway fatigue damage. Do not mix lubricants of different brands.

5.4 Speed Parameter Note

GA large ball structure improves load capacity while limiting DN speed slightly lower than standard ball ACD bearings of same specification. Sufficient speed safety margin shall be reserved under continuous heavy load; long-term operation near limiting speed is not recommended.

6 Daily Maintenance & Fault Troubleshooting

Carry out multi-stage low-speed running-in after assembly. Do not raise rotating speed to working level until temperature rise and vibration stabilize. Open bearing has no built-in dust shield, labyrinth seal or air curtain dust-proof structure must be equipped 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, check in sequence: lubrication supply & oil cleanliness, bearing pairing accuracy, preload value, assembly coaxiality and external cutting impact load. Regularly monitor spindle temperature to identify early bearing fatigue.