Bearing Number Meaning: How to Read Bearing Codes

Every rolling bearing carries a code on its side. Once you know how to read it, you can identify the bearing type, its size and its seals in seconds, and order the right replacement the first time.

By Hakimi Industrial Suppliers · Updated 15 October 2026 · 6 min read

What a bearing number tells you

Most metric rolling bearings follow an ISO-based numbering system used across major manufacturers. A typical code such as 6205-2RS C3 has two parts: a basic number (6205) that gives the bearing type, the dimension series and the bore size, and suffixes (2RS, C3) that describe seals or shields, internal clearance and special features.

Step 1: The first digit is the bearing type

Code Bearing type 6 Deep groove ball bearing (the most common type) 7 Angular contact ball bearing 1 / 2 (e.g. 12xx, 22xx) Self-aligning ball bearing 2 (e.g. 222xx, 223xx) Spherical roller bearing 3 (e.g. 302xx, 322xx) Tapered roller bearing 5 (e.g. 511xx) Thrust ball bearing N, NU, NJ Cylindrical roller bearing

Roller bearings often use five-digit codes, so always read the complete number before deciding the type.

Step 2: The second digit is the series

The series shows how heavy the bearing is for a given bore. A higher series means a larger outer diameter and width, and therefore a higher load capacity, while the bore stays the same.

Series Load class Example (bore × OD × width, mm) 60xx Extra light 6005: 25 × 47 × 12 62xx Light 6205: 25 × 52 × 15 63xx Medium 6305: 25 × 62 × 17 64xx Heavy 6405: 25 × 80 × 21

Step 3: The last two digits give the bore size

Bore code Bore diameter 00 10 mm 01 12 mm 02 15 mm 03 17 mm 04 and above Code × 5 (e.g. 05 = 25 mm, 08 = 40 mm)

Miniature bearings are an exception. In a 608 bearing, the last digit is the bore itself: 608 has an 8 mm bore.

Step 4: Suffixes for seals, shields and clearance

Suffix Meaning Z Metal shield on one side ZZ / 2Z Metal shields on both sides RS Rubber contact seal on one side 2RS (2RSH, LLU, DDU) Rubber seals on both sides (names vary by manufacturer) C3 Internal clearance greater than normal C2 Internal clearance less than normal CN Normal clearance (usually not marked) N / NR Snap ring groove / groove with snap ring

Shields (ZZ) keep out larger particles with very low friction. Rubber seals (2RS) give better protection against dust and moisture, at slightly higher friction. C3 clearance is commonly used where the bearing runs hot or is fitted tightly, for example in many electric motors.

Common deep groove ball bearing sizes

Bearing Bore (mm) OD (mm) Width (mm) 6201 12 32 10 6202 15 35 11 6203 17 40 12 6204 20 47 14 6205 25 52 15 6206 30 62 16 6305 25 62 17 6306 30 72 19

These are standard boundary dimensions. Always confirm critical dimensions against the manufacturer catalogue for your application.

Worked example: 6205-2RS C3

• 6 = deep groove ball bearing
• 2 = light series
• 05 = 5 × 5 = 25 mm bore
• 2RS = rubber seals on both sides
• C3 = greater than normal internal clearance

Result: a sealed deep groove ball bearing measuring 25 × 52 × 15 mm with C3 clearance.

What if the number has worn off?

Measure the bore (inner diameter), the outer diameter and the width with a vernier caliper, note whether it has shields or seals, and match the three dimensions against a size chart like the one above. Sharing these measurements is enough for a supplier to identify the bearing.

Buying bearings in Bangalore

Hakimi Industrial Suppliers is located at 2nd floor, 178, Sadar Patrappa Rd (S.P. Road), Bengaluru. You can share the bearing number or dimensions by call or WhatsApp on 97397 55252, or browse our ball bearings and V-belts pages.

Hakimi Industrial Suppliers · S.P. Road, Bangalore

Need a bearing in Bangalore?

Share the full bearing number (including the suffix) or its bore, outer diameter and width with Hakimi Industrial Suppliers on S.P. Road. Availability and brands are confirmed at the time of quotation.

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