NMT Ltd.
Corporate Communications Department
Japan NMT 7006 ACDGC/P4A Precision Angular Contact Bearing 25° High-Load D-Type Single Matchable Bearing with Class C Measuring Load P4A Grade
1 Complete Model, Dimensions, Loads & Technical Parameters
Full Model: 7006 ACDGC/P4A
Model Code Explanation
7006: Basic dimension of 70 series precision angular contact ball bearing;
ACD: 25° contact angle, high-load D geometry;
GC: Class C measuring load standard for duplex matching preload;
P4A: P4A ultra-precision tolerance grade.
Standard Dimension Parameters
Bore d: 30 mm
Outer diameter D: 55 mm
Width B: 13 mm
Contact angle: 25 °
Performance Data
Basic dynamic load rating Cr: 13.8 kN
Basic static load rating C0r: 7.65 kN
Speed note: Contact SKF to obtain reference achievable rotational speed.
Full Product Attributes
Contact form: standard two-point contact
Number of bearings: 1 (single unit)
Ring structure: integrated inner ring and outer ring
Internal design: high-load D-type optimized design
On-site matching available: Yes, back-to-back (<>), face-to-face (><), tandem (>>)
Duplex arrangement: none (single unit supplied, matched on site)
Preload specification: Measuring load, Class C
Tolerance class: P4A precision grade
Material: bearing steel
Coating: uncoated
Seal: open type without seals
Pre-filled lubricant: none, lubrication configured on site
Indicative carbon footprint for new product: 0.41 kg CO₂e
Net weight: 0.11 kg
eClass code: 23-05-08-04
UNSPSC code: 31171531
Speed note: The 25° large contact angle provides outstanding axial load capacity and rigidity. D-type design optimizes rolling element load zone, suitable for medium speed conditions with relatively heavy axial load. Class C measuring load fits light and medium preload matching schemes; single bearings can be freely combined into DB/DF/DT layouts with wider clearance range compared to Class B group.
2 Structure & Operating Characteristics
Japan NMT 7006 ACDGC/P4A is a single precision angular contact ball bearing of 7006 size with 25° high-load D-type design and integrated bearing steel rings. D-type geometry optimizes contact between rolling elements and raceways to increase load rating and moment resistance.
Supplied as individual single bearing. Controlled under Class C measuring load at factory, dimensional dispersion within same batch is controllable to enable on-site duplex assembly into back-to-back, face-to-face or tandem sets. Open construction supports oil-air lubrication and high-speed grease; no lubricant pre-filled inside bearing.
Bearing steel features high rigidity and wear resistance with stable load performance. The 25° contact angle delivers higher axial stiffness than smaller angle variants, ideal for spindles subjected to significant axial load and overturning moment. Class C measuring load provides wider clearance range, suitable for applications with moderate temperature rise requiring tiny expansion allowance. Users can select arrangement: DB back-to-back for moment resistance, DF face-to-face for improved centering accuracy, DT tandem for large unidirectional axial force.
3 Core Performance Advantages
1. High-Load D Geometry + 25° Contact Angle: Strong axial rigidity, high load rating and excellent resistance to overturning moment.
2. Class C Measuring Load Standard: Moderate clearance range, suitable for moderate temperature rise conditions, flexible for on-site duplex matching.
3. Bearing Steel Substrate: High hardness and wear durability for long-term continuous medium & heavy load operation.
4. P4A Precision Grade: Strict control of rotary runout to sustain precision machining operation.
5. Open Seal-Free Construction: Eliminates seal friction loss, provides excellent heat dissipation and full compatibility with oil-air lubrication.
4 Typical Application Scenarios
4.1 Precision Machining Spindles for CNC Machine Tools: Medium & small milling spindles, grinding spindles, general engraving machine spindles.
4.2 Ball Screw Support Units for CNC Equipment: Feed screws for machining centers, bidirectional feed support seats for machine tools.
4.3 Heavy-Duty Precision Rotary Tables for Automation: Precision indexing devices, heavy-duty fine-adjustment rotary mechanisms.
4.4 Precision Rotary Supports for General Test Equipment: Test machine spindles, optical rotary platforms under medium load.
5 Assembly Specifications & Usage Guidelines
5.1 Assembly Environment & Operation Standards
P4A high-precision bearings must be assembled in dust-free clean environment. Thoroughly remove burrs and contaminants from shaft and housing mating surfaces. Controlled thermal mounting is recommended. Striking bearing faces and raceways is forbidden. For duplex matching, prioritize bearings from the same production batch to guarantee uniform preload.
5.2 Matching Layout & Preload Instructions
Supplied as separate single units; duplex layout assembled on demand. Class C measuring load is suitable for light preload and standard preload configuration. DB back-to-back offers best anti-overturning performance; DF face-to-face compensates minor mounting coaxial errors; DT tandem only for sustained unidirectional axial load. Preload magnitude controlled by lock nuts and spacer sleeves.
5.3 Lubrication Matching Solutions
No pre-filled lubricant inside bearing. Oil-air lubrication preferred for continuous high-speed machining; premium high-speed grease for intermittent operation. Do not mix different lubricant grades. Maintain lubrication pipelines regularly to avoid contaminants entering raceways.
5.4 Speed Parameter Note
Request reference limiting speed data from SKF. Bearing steel delivers high load capacity; sufficient lubrication and heat dissipation must be secured during continuous high-speed operation.
6 Daily Maintenance & Fault Troubleshooting
Implement multi-stage low-speed running-in after assembly, continuously monitor temperature and vibration. Rated speed operation permitted only after stable condition is confirmed. Open design lacks dust and cutting fluid protection; external shaft seals must be installed for machining applications.
Maintain steady oil supply to form complete lubricating film on raceways. In case of abnormal temperature rise, vibration growth or periodic noise, sequentially check duplex layout, preload value, mounting coaxiality, lubrication status and contamination ingress. Avoid long-term shock overload.