A basic bearing designation typically contains three to five digits. Some products, like cylindrical roller bearings, can have a combination of alphanumeric characters.

1. The first number relates to the bearing type, as shown in the table below

2.The second digit ( 4 digit bearing number) and combination of second & third digits (5 digits bearing number) identifies the dimensional series symbol ( the width series and diameter series symbol are combined and called the dimensional series symbol).

For radial bearings, outer diameter increases with the diameter series symbol 7,8,9,0,1,2,3,4.

width series symbols include 0,1,2,3,4,5,6 and these combined with the respective diameter series symbos. Width series symbol become wider in this ordering system to match the respective diameter series symbol.

For the standard radial ball bearings, the width series symbol is omitted and the bearing number is expressed by 4 digits.also ,it is common practice to omit the width series symbol of the zero for cylindrical roller bearings. thrust bearing use the term height symbol rather than width symbol.

3.The last number (which is a set of two numbers) indicates the bore (in mm) of the bearings.

All bearings are designated with metric standards, not inches. Numbers are as follows:
00 = 10 mm
01 = 12 mm
02 = 15mm
03 = 17 mm
For 20-480mm bore bearings: Last 2 digits x 5 = Bore (mm)

Prefix And Suffix Meaning 

Cylindrical Roller Bearing Example and Designation Meaning

Cylindrical roller bearings are identified by the prefix “N”, “NU”, “NJ”, or “NUP”, followed by numbers and sometimes suffixes that specify bore size, clearance, cage, or design type.

⚙️ Basic Structure of Cylindrical Roller Bearing Number

Example: NU 2208 ECP C3

Let’s decode it step-by-step 👇

✅ Full Meaning:
NU 2208 ECP C3 is a single-row cylindrical roller bearing, 40 mm bore, medium series, high load design (E), polyamide cage (CP), and greater clearance (C3).