What Are Our Concerns About Bearings（19）

Q1:How does a general bearing judge its inner diameter, outer longitude and thickness (e.g. 6203Z) according to its code name?  

A:First know the code name of rolling bearing  

(Based on new code name)  

Bearing model, the size of bearing can be judged intuitively from the model.  

Type code, the bearing structure type can be judged intuitively from the bearing (mainly according to the shape of the rolling body classification).  

Outer diameter code, from the bearing type can only be judged series, and what series what size.  ISO and bearing main producers have standards, countries basically follow ISO standards.  For details, refer to the manual.  

The situation of width code and outer diameter series code is basically the same, we also need to check the manual.  

Inner diameter code:  

Bearing basic codes are: three numbers, four numbers, five numbers, with a slash.  

One, three numbers: from right to left, a number represents the size of the internal meridian, the number is a few inner diameter is a few mm.  For example, the inner diameter of the 608 bearing is 8mm.  

Two, four and five numbers: from right to left, the first two numbers are the inner diameter code.  

Among them:  

00 indicates that the inner diameter of the bearing is 10mm,  

01 indicates that the inner diameter of the bearing is 12mm,  

02 indicates that the inner diameter of the bearing is 15mm,  

03 indicates that the inner diameter of the bearing is 17mm.  

The inside dimensions above 04 are equal to the number from right to left, multiplying the first two numbers by five.  

For example, the inside diameter of 6201 is 12mm.  

The bearing diameter of 6204 is: 20mm.  

Three, bearing model has a slash, the number on the right side of the slash is the size of the inner diameter.  

For example, the inside diameter of NK20/16 is 16mm.  

The inner diameter size of 230/500 bearings is 500mm.  

This is the basic method for calculating the inner diameter of metric rolling bearings.  

Inch bearings and some individual factory express methods, there are other methods.  

Outside diameter code resolution:  

Example: 6205  

05 is the inner diameter code.  Inner diameter size (mm) =05*5=25mm  

2 indicates the diameter series code.  (For bearings with the same inner diameter series code, diameter series code indicates the size of the outer diameter of the bearing).  Same inner diameter, outer diameter 4 > 3 > 2 > 0 > 9 > 8 > 7 (some manufacturers have 7 series, some do not)

That is to say, 6405, 6305, 6205, 6005, 6905 (61905), 6805 (61805), 6705, these bearings are deep groove ball bearings with the same inner diameter and successively smaller outer diameter.  

Width code:  

Bearing type number from right to left, the fourth number, is the width code.  Example: 21315 is a “1” series width.  6205 is the “0” series width (actually 6 (0) 205, width “0” omitted.  

0 “1” 2 “3” 4 “5” 6 “……  In the case of the same inner diameter, the same outer diameter, the width size becomes wider in turn.  

The type code  

Count one from left to right or add one and the second number together  

“6” means deep groove ball bearing  

“4” means double row deep groove ball bearings  

“2” or “1” indicates self-aligning ball bearings (there are four numbers in the basic model 0: indicates double-row self-aligning ball bearings  

Example: 2205 1204  

The standard model should be 02205. The 0 is omitted.  

The standard model should be 01204.  

“21”, “22”, “23” and “24” denote self-aligning roller bearings.  

“N” denotes cylindrical roller bearing (including short cylindrical roller and part of slender needle roller)  

“7” means angular contact ball bearing  

“3” means tapered roller bearing (metric)  

“51”, “52” and “53” indicate centripetal thrust ball bearings (five numbers for basic models)  

“81” means thrust short cylindrical roller bearing  

“29” means thrust self-aligning roller bearing  

Q2:What are the parameters of bolted needle roller bearings CF3?

A:CF3 bolted roller needle roller bearings  

Specific dimensions: OUTER diameter: 10

width of outer ring: 7   Thread: M3x0.5

Maximum allowable load: 0.36kN

Limit speed: 47000 r/min   Mass: 4.5g.  

Q3:Inner diameter 14 outer diameter 20 width 20, what type of needle roller bearing is it?

A:Refer to the Machine Manual:  

Stamped outer ring needle roller bearing HK1420  

Q4:What about a 5-digit bearing number?

A:Basic types of rolling bearings  

Bearing type New Standard Old Standard Bearing type New Standard Old Standard Double row angular contact ball bearing 0 6 Cylindrical roller bearing N 2 Self-aligning ball bearing 1 1 Outer spherical ball bearing U 0 Self-aligning roller bearing 2 3 Four-point contact ball bearing QJ 6 Tapered roller bearing 3 7 Needle roller bearing (solid ring) NA  Double row deep groove ball bearing 4 0 Stamping outer ring needle roller bearing (perforated type) HK HK 5 8 Stamping outer ring needle roller bearing (sealed type) BK BK deep groove ball bearing 6 0 needle roller and cage assembly K K Angle contact ball bearing 7 6 Thrust needle roller and cage assembly AXK 889  Thrust cylindrical roller bearing 8 9 thrust tapered roller bearing 9 9 1  The basic code  

The basic code is used to indicate the inner diameter, diameter series, width series and type of bearings, generally five digits, first described as follows:  

• 1) Bearing inner diameter is represented by one or two digits from the right of the basic code number.  For the common inner diameter d=20~480mm bearing inner diameter is generally a multiple of 5, these two numbers represent the bearing inner diameter size divided by 5 quotient, such as 04 represents D = 20mm;  12 means d = 60mm and so on.  For bearings with inner diameters of 10mm, 12mm, 15mm and 17mm, the inner diameters are 00, 01, 02 and 03 respectively.  For bearings with inner diameter less than 10mm and greater than 500mm, the inner diameter expression method is otherwise stipulated, which can be referred to GB/T272-93.  

• 2) The diameter series of bearings (that is, the bearing with the same structure and the same inner diameter changes in the outer diameter and width series) are represented by the third digit from the right of the basic code.  For example, for centripetal bearings and centripetal thrust bearings, 0 and 1 represent extra-light series;  2 indicates light series;  3 indicates the medium series.  4 indicates the repeated series.  The size pairs between the series are shown in the figure below.  The thrust bearing is the same as the centripetal bearing except that 1 is used to represent the extra-light series.  

• 3) The width series of bearings (that is, the change series of bearing width with the same structure, inner diameter and diameter series) is represented by the fourth digit from the right of the basic code.  Most bearings can not mark the width series code 0 in the code, but for self-aligning roller bearings and tapered roller bearings, the width series code 0 should be marked.  

Diameter series code and width series code collectively referred to as size series code.  

• 4) Bearing type codes are represented by the fifth digit from the right of the basic code (for cylindrical roller bearings and needle roller bearings and other types of codes are letters).  

Q5:What is the meaning of needle roller bearing type HK?

A:H Hardened card type punch cage K taper hole 1:12

Q6:What are the code classifications of rolling bearings?

A:Rolling bearing Classification Code:  

“0” indicates double row angular contact ball bearings  

“1” means aligning ball bearing  

“2” means self-aligning roller bearing and thrust self-aligning roller bearing  

“3” means tapered roller bearing  

“4” means double row deep groove ball bearings  

“5” means thrust ball bearing  

“6” means deep groove ball bearing  

“7” means angular contact ball bearing  

“8” means thrust cylindrical roller bearing  

“9” means thrust tapered roller bearing  

“N” stands for cylindrical roller bearings and needle roller bearings  

Cylindrical roller bearing code after the general additional 1 or a few letters code, used to represent those fender structure type, such as: NJ, NU, NUP and so on.  For double – or multi-row cylindrical roller bearings are denoted by the letter NN.  Needle roller bearings are usually represented by the letters NA or NK.  

“U” stands for outer spherical ball bearing