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Non standard size bearing code

Time:2021-07-21 Views:594
The code of non-standard size bearing is composed of basic code, pre code and post code. The basic code consists of two parts: type code and dimension expression; The codes of front and rear bearings are the same as those of common bearings.

(1) Type code

Same as common bearings, see table 2-1.

(2) Dimension representation

1) There are two ways to express the size series code.

① The non-standard outer diameter or width (height) dimension shall be taken as the closest diameter series or width (height) series by comparing the standard dimension or according to the rules of external dimension extension specified in GB / t273.2 and GB / t273.3, and the letter shall be added after the basic code, as shown in table 2-19.

Table 2-19 representation of dimension series






Non standard outer diameter

Width (height) non standard

Outside diameter, width (height) non standard (standard inside diameter)

② When the non-standard inner diameter, outer diameter and width (height) dimension can not be compared with the standard dimension or according to the external dimension extension rules specified in GB / T 273.2 and GB / T 273.3, it shall be represented by indefinite series, as shown in table 2-20.

Table 2-20 representation of dimension series of indefinite series

Bearing type

Indefinite series

keep on record

Width (height) series code

Diameter series code

Radial bearing



1. The indefinite series of double row angular contact ball bearing is 46

2. "O" is omitted when indefinite series 06 is combined with type code (except tapered roller bearing and double row deep groove ball bearing)

thrust bearing




One way thrust bearing, indefinite series 17

Two way thrust bearing, indefinite series 27

2) The inner diameter is expressed according to table 2-21.

Table 2-21 inner diameter representation

internal diameter


Standard size

According to table 2-5

Non standard size

The integer below 500mm which can be divided by 5 is expressed by quotient divided by 5. Other dimensions are directly expressed by actual inner diameter mm, but shall be separated from dimension series code by "/"

Example: 66 / 6.4 - deep groove ball bearing, indefinite series, inner diameter 6.4mm;

61700 X1 - a deep groove ball bearing, non-standard outer diameter, close to diameter series 7;

62 / 14.5 - deep groove ball bearing, size series 02, inner diameter 14.5mm;

52706 - bidirectional thrust ball bearing, indefinite series, inner diameter 30mm

3) The dimension of the bearing is expressed as:

"/ inner diameter × external diameter × "Mm of actual width"

Example: K / 13 × seventeen × 13 -- needle roller and cage assembly, FW = 13mm, EW = 17mm, be = 13mm;

HK/12 × seventeen × 15 -- needle roller bearing with punched outer ring, FW = 12mm, d = 17mm, B = 15mm.

4) When the codes of several non-standard bearings of the same type with little difference in external dimensions are the same, the basic codes shall be distinguished by adding the symbol "-" followed by the serial numbers 1, 2, 3.

Example: 61700x1 - 1

61700X1 -2

52706- 152706-2