The basic code is used to indicate the bearing's inner diameter, diameter series, width series and type. Generally, the maximum number is five digits. The first part is described as follows:

1) The bearing inner diameter is represented by the first and H-digit Numbers from right of the basic code.For bearing bore diameter d=20 ~ 480mm in common use, it is usually a multiple of 5. These two Numbers represent the quotient of bearing bore size divided by 5. For example, 04 represents d= 20mm.12 means d is equal to 60mm and so on.For bearings of 10mm, 12mm, 15mm and 17mm, the bore codes are 00, 01, 02 and 03, respectively.For bearings with bore diameter less than 10mm and greater than 500mm, the method of representing bore diameter is otherwise stipulated, see GB/T272-93.

2) The diameter series of bearings (i.e., the variation series of outer diameter and width of bearings with the same structure and inner diameter) shall be represented by the third digit from the right of the basic code.For example, for radial bearings and radial thrust bearings, 0 and 1 represent extra-light series;2 represents the light series;3 represents medium series;Four represents the heavy series.The size pairs between the series are shown below.The thrust bearings are in accordance with the expression of the centrist-bearing except for the extra-light series represented by 1.

3) The bearing width series (i.e. the bearing width variation series with the same structure, inside diameter and diameter) is represented by the fourth digit from the right of the basic code.When the width is shown in FIG. 13-4, the diameter series is classified as 0 series (normal series), the width series code O may not be indicated in the code for most bearings, but for self-aligning roller bearings and tapered roller bearings, the width series code 0 should be indicated.

Diameter series code and width series code are collectively called size series code.

4) The bearing type code is represented by the fifth digit from the right of the basic code (for cylindrical roller bearings and needle roller bearings, the code name is letter).

2.Post code

The rear designation of the bearing is used to indicate the bearing structure, tolerances, special material requirements, etc., in letters and Numbers.The content of post code is very much, the following introduces a few commonly used code.

1) Internal structure code refers to the different internal structure of the same type of bearing, which is represented by letters followed by the basic code.For example, angular contact ball bearings with contact angles of 15°, 25° and 40° are respectively represented by C, AC and B in terms of their internal structures.

2) Tolerances of bearings are divided into class 2, class 4, class 5, class 6, class 6X and class 0. There are six grades in total, which are successively from high to low, and their codes are respectively/PZ, / P4, / P5, / P6, / P6X and/PO.Among the tolerance classes, 6X class is only applicable to tapered roller bearings;Class e 0 is a normal class, not indicated in the wheel bearing code.

3) The commonly used radial clearance series of bearings are divided into 1 group, 2 group, 0 group, 3 group, 4 group and 5 group. There are 6 groups in total, and the radial clearance goes from small to large in turn.The clearance of Group O is the commonly used clearance group, which is not marked in the bearing code, and the rest clearance groups are respectively represented by/CI, / CZ, / C3, / C4 and/CS in the bearing code.

3.Front code

The prefix code for a bearing is used to indicate the component parts of the bearing and is denoted by letters.For example, L is used to represent the detachable ring of separable bearing;K represents the rolling body of the bearing, the retainer assembly and so on.

The practical application of the rolling bearing type is a lot of, the corresponding bearing code is more complex.The code introduced above is the most basic bearing code, the most commonly used part, familiar with this part of the code, you can identify and check the commonly used bearing.