Anti-friction bearings, also known as rolling bearings, are numbered according to standardized systems. The most commonly used numbering systems for anti-friction bearings are the ISO (International Organization for Standardization) and the ABMA (American Bearing Manufacturers Association) numbering systems.
ISO numbering system: The ISO system uses a five-digit code to represent different characteristics of the bearing. The digits represent various parameters such as the bearing type, dimensions, and other specific details. The digits are organized as follows:
- First digit: Represents the bearing type and is generally a number from 1 to 9, indicating different types of bearings.
- Second and third digits: Indicate the bearing series, which represents the general size and design of the bearing.
- Fourth and fifth digits: Represent the bearing size, which specifies the bore diameter (inner diameter) of the bearing.
For example, an ISO bearing with the number 6204 represents a deep groove ball bearing with a bore diameter of 20 mm.
ABMA numbering system: The ABMA system, also known as the ANSI/ABMA standard, uses a four or five-digit code to designate various characteristics of the bearing. The digits provide information about the bearing type, dimensions, and specific details. The digits are organized as follows:
- First digit: Indicates the bearing type, generally represented by a number from 0 to 9, defining different bearing types.
- Second and third digits: Represent the bearing series, which provides information about the general size and design of the bearing.
- Fourth and fifth digits (optional): Can represent additional details such as the bore diameter, width, or other specific features.
For example, an ABMA bearing with the number 30309 indicates a tapered roller bearing in the 30000 series with a 45 mm bore diameter.
It's important to note that both the ISO and ABMA numbering systems provide standardized codes to identify and classify different types and sizes of anti-friction bearings, making it easier to specify and select the appropriate bearing for specific applications.