BEARING IDENTIFICATION NUMBER
“WHAT ARE THEY”?
A GUIDE TO DECODE SIZE AND TYPE
There are simple ways to know the bearing designation or kind, a little knowledge can help in understanding the type or kind that u need. The bearings are identified by the number pattern which in most cases gives the information of size and type, also the cage, and the groove can also be identified by the alphanumeric code.DECODING THE KIND AND INNER SIZE
Another method is to look at the number on the bearing itself for ex 6205zz.The “6” or the first number determines the bearing type which is ball bearing series. The last two numbers determines the inner size, to get the size multiply the last two numbers by 5 as a standard rule in this case 05 * 5= 25 mm. Another example would be 22216, the first number “2” tells us that it is a spherical roller bearing and to get the inner size we multiply the last two numbers by 5, (16 * 5) = 80mm. Many bearings have similar inner sizes such as “6205” size is 25*52*15, “3205” size is 25*52*20.6, in this example we see the last numbers or diameter are different 15 contrast with 20.6 but the inner size is similar which is 25 therefore a little knowledge about the initial number is important which will give us an indication of the type. Also if the last number is less than 04 then the multiplication formula cannot be applied for ex “6203” the inner size is 17mm as a rule of thumb less than 04 inner sizes are given below.| NUMBER | INNER (MM) |
| 6200 | 10 |
| 6201 | 12 |
| 6202 | 15 |
| 6203 | 17 |
TABLE TO DETERMINE THE BASIC KIND OR TYPE
| BALL BEARING | 0, 1, 2, 3, 4, 5, 6,7, UC |
| TAPPER ROLLER | LM, HM, 1, 2, 3, 5, 7 |
| SPHERICAL ROLLER | 222, 23, 24, 29 |
| CYLINDRICAL | N, NU, NJ, NF, NUP |
| PILLOW BLOCK | P, F, FL, T, FC, SN |
| ADAPTER SLEEVES | H, HE |
MEANING OF SUFFIX
BALL BEARING SUFFIX:
| LLU, 2RS, LLB(NTN), DDU(NSK) | RUBBER SEAL |
| ZZ | STEEL SEAL |
| C3, C4 | HIGH CLEARANCE |
SPHERICAL ROLLER SUFFIX :
| MB | BRASS CAGE |
| CC | STEEL CAGE |
| W33 | OIL GROOVE |
CYLINDRICAL ROLLER PREFFIX:
| NJ | ONE SIDE LOCK |
| NU | FREE MOVEMENT BOTH SIDE |
| NUPK | ONE SIDE PLATE |
| N | OUTER RING |
CYLINDRICAL ROLLER SUFFIX:
| ECJ | |
| ECP | POLYAMIDE CAGE |
| EM | BRASS CAGE |
– By Shamoon Sharif
