1 Product Overview: A Versatile Choice for Bearing Assembly

NMT 7005 CDGC/P4A is a universal paired ultra-precision single-row angular contact ball bearing, belonging to the 7000 series of high-precision angular contact bearings. This bearing adopts a 15° contact angle and a high-load D-type design, integrating P4A-level ultra-precision tolerances and universal pairing (G) capabilities. It is an ideal choice for scenarios requiring comprehensive requirements for precision, load-bearing capacity, and rotational speed, such as machine tool spindles, high-speed machining centers, precision grinding machines, and robot joints.

 

The 15° contact angle is a small contact angle design optimized for high-speed applications. Compared to the same B-type design high-speed bearings, the D-type high-load design can withstand higher loads. The universal pairing (G) design allows the bearing to be flexibly configured in three installation modes: back-to-back (DB), face-to-face (DF), or series (DT), without the need for spacer plates to achieve the even distribution of load between the two bearings. The factory preset medium preload (Class C) enhances system rigidity while controlling the temperature rise during high-speed operation. The basic rated dynamic load reaches 9.56 kN, making it one of the balanced configurations in this size range.

 

Core dimensions: Inner diameter 25 mm, outer diameter 47 mm, width 12 mm

 

Performance parameters:

 

Basic rated dynamic load: 9.56 kN

 

Basic rated static load: 5.2 kN

 

Operating temperature range: -30°C to 110°C

 

Ball diameter: 6.35 mm / Number of balls: 14

 

Net weight: 0.077 kg

 

Precision grade: P4A level - Dimensional accuracy conforms to ISO P4 standard, rotational accuracy exceeds ISO P4

Tolerance: Inner diameter tolerance -0.004mm to 0, outer diameter tolerance -0.004mm to 0

Pairing preload: Medium preload (Class C)

 

2 Model Code Interpretation

Code Meaning

7005 Basic model, inner diameter 25mm, outer diameter 47mm, width 12mm

C 15° contact angle, optimized for high-speed applications

D High-load D-type design, capable of withstanding higher loads compared to B-type and E-type designs

G Universal pairing (Universally Matchable) - Allows for flexible installation without spacers

C Medium preload (Class C)

P4A Ultra-precision tolerance grade - Dimensional accuracy P4 level, rotational accuracy exceeds P4 level

3 Structural and Design Features: Precision Logic of High Load and Universal Pairing

The design of NMT 7005 CDGC/P4A embodies a deep understanding of "high load capacity", "high speed", and "flexible configuration".

 

15° contact angle and CD high-load D-type design. The contact angle is 15°, a small contact angle design optimized for high-speed applications. The 15° contact angle maintains good axial load-bearing capacity while maximizing high-speed performance. The CD-type high-load D-type design optimizes the size, quantity of rolling elements, and the curvature of the raceway to achieve high stiffness, high load-bearing capacity, and high speed in a compact 25×47mm size. It is designed for operating conditions requiring high load capacity and high speed, and compared to B-type and E-type high-speed bearings, the D-type design can withstand higher loads.

 

Universal pairing (G) - Three configurations, one bearing. The "G" suffix indicates universal pairing (Universally Matchable). The universal pairing design allows the bearing to be flexibly configured in three installation modes: back-to-back (DB), face-to-face (DF), or series (DT). Universal pairing bearings can be installed arbitrarily without the need for spacers or similar devices to achieve the even distribution of load between the two bearings. Users do not need to prepare different bearing models for each configuration; a single set of bearings can cover various installation requirements.

 

Medium preload (Class C) - Balancing load and speed. The "C" in the "GC" suffix indicates medium preload (Moderate Preload, Class C). Medium preload significantly enhances system rigidity while keeping friction temperature rise within a reasonable range, ensuring that the bearings do not lose accuracy due to overheating during high-speed operation. Compared to light preload (Class A), medium preload (Class C) provides higher system rigidity and is suitable for scenarios with higher bearing capacity requirements.

 

Phenolic cage - Guarantee for high-speed operation. The phenolic (phenolic resin) cage has a good strength-to-weight ratio and low friction characteristics, capable of withstanding large inertial forces and operating temperatures up to 120°C. During high-speed operation, the lightweight design of the cage effectively reduces the influence of centrifugal force on the guiding accuracy of the rolling elements.

 

Chrome steel rings and rolling elements. The rings and rolling elements are made of high-purity chrome steel, providing excellent fatigue resistance and dimensional stability under heavy load and high-speed conditions.

 

P4A ultra-precision tolerance. P4A level of precision means that the size accuracy conforms to the ISO P4 standard, and the rotational accuracy exceeds ISO P4. This precision level ensures that the bearing maintains extremely low radial runout and axial play during high-speed operation.

 

4 General pairing and medium preload engineering value

The combination of general pairing and medium preload gives the NMT 7005 CDGC/P4A a unique value positioning in high-speed and high-load application scenarios:

 

Load advantage. The high-load D-type design of this bearing enables the basic rated dynamic load to reach 9.56 kN. Compared to B-type and E-type high-speed bearings, the D-type design can withstand higher loads. Medium preload (Class C) further enhances system rigidity, suitable for scenarios with higher bearing capacity requirements.

 

Flexible configuration. The general pairing design allows the same set of bearings to be flexibly configured as back-to-back, face-to-face, or series installation. Compared to fixed pairing, general pairing does not require users to specify the installation configuration in advance, significantly simplifying inventory management and selection processes.

 

Balance of speed and load. Class C medium preload significantly enhances system rigidity while keeping friction temperature rise within a reasonable range. Compared to light preload (Class A), medium preload (Class C) provides higher system rigidity; compared to heavy preload, it maintains better high-speed performance.

 

Accuracy consistency. P4A level of precision and precise pairing ensure that the size and preload of the bearing are highly consistent, and after installation, no additional adjustments are needed to achieve stable system rigidity and rotational accuracy.

 

5 Core application scenarios

The NMT 7005 CDGC/P4A is mainly used for scenarios with comprehensive requirements for high precision, high load, and high-speed performance.

 

Machine tool spindles and high-speed machining centers. The spindles of CNC machining centers, precision milling machines, and grinding machines need to withstand heavy-load cutting during high-speed operation. The 15° contact angle high-speed characteristic, high-load D-type design, and P4A level of precision of the 7005 CDGC/P4A ensure that the spindle meets the requirements of speed, load, and accuracy in extreme conditions.

 

Industrial robot joints. High-precision robot joints require compact bearing dimensions and reliable load-bearing capacity. The general pairing design and medium preload of the 7005 CDGC/P4A provide flexible configuration options and stable rotational support for robot joints.

 

Precision grinding spindle. The tolerance for spindle runout is extremely low in grinding processing. The P4A level of precision and high-load D-type design meet the strict requirements of precision grinding.

 

Semiconductor manufacturing equipment and medical imaging equipment. The scenarios such as wafer handling and precise alignment have extremely high requirements for the precision, cleanliness and reliability of bearings. Medical imaging equipment needs to maintain low vibration and high precision during high-speed rotation.

 

High-speed motors and power tools. High-frequency motors, power tools and other equipment need to operate for a long time at extreme rotational speeds. The lightweight structure of phenolic cages and the high durability of chrome steel effectively reduce heat generation and extend continuous operation time.

 

3D printers and automation equipment. Precise linear motion and high-speed positioning have continuous requirements for the precision and stability of bearings. The lightweight design and high rotational speed tolerance make it an ideal choice for precision manufacturing tasks.

 

6 Installation and Maintenance Guide

Matching Installation Tips. This bearing is designed for general matching and can be flexibly configured as back-to-back, face-to-face or series three installation methods. Select the installation method based on the load direction: back-to-back (DB) - wide end faces are opposite, the rigidity is the maximum, suitable for heavy load and high rigidity requirements; face-to-face (DF) - narrow end faces are opposite, suitable for scenarios with uncertain axial load direction; series (DT) - wide end faces are in the same direction, used when a unidirectional axial load is extremely large. The factory preset medium preload (C grade) has been achieved through precise matching, and no additional adjustment of preload force is required after installation. General matching bearings do not require spacers to achieve the average distribution of load between two bearings.

 

Lubrication Management. This bearing is of an open (Open) design, facilitating lubrication and maintenance. Grease lubrication can meet requirements in most high-speed scenarios, and low-viscosity, low-volatile, high-speed-specific lubricants are recommended. The applicable working temperature range of the bearing is -30°C to 110°C.

 

Operation Monitoring. Regular monitoring of bearing temperature and vibration is required during high-speed operation. An abnormal increase in temperature usually indicates a failure in lubrication; vibration spectrum analysis can identify rolling element or raceway damage at an early stage.

 

Sealing Protection. This bearing is of an open design, without seals. After installation, it is necessary to ensure that the overall sealing system of the equipment is effective to prevent contaminants such as dust and cutting fluid from invading the internal of the bearing.

 

7 Customized Services and Supply Chain Assurance

NMT 7005 CDGC/P4A follows international standard dimensions (25×47×12mm) and P4A accuracy grade, achieving complete interchangeability with existing bearings of the same specification. NMT supports non-standard customization - including special preload levels, special lubrication schemes, and matching bearing configurations. Mainstream specifications have ready-made inventory in stock, and the professional technical team provides selection and technical support. The net weight of the product is 0.077 kg.

 

8 Value Summary

In high-speed heavy-load cutting of machine tool spindles, in precise motion of robot joints, and under the strict cleanliness standards of semiconductor equipment - NMT 7005 CDGC/P4A ultra-precision general matching single-row angular contact ball bearings with a 15° contact angle, high rotational speed gene, heavy-load capacity of D-type design, three flexible configurations of general matching, medium preload's rigidity and temperature rise balance and P4A grade ultra-precision tolerance, release the precision power beyond size in a compact 25×47×12mm size. Single-row design, general matching, three configurations - achieving "high load capacity", "high precision" and "flexible configuration" simultaneously.