6205-ZZ and 6203-2Z look similar because both end with a two-shield suffix. The base numbers are different, so the Bearing Number Decoder keeps the bore and series separate from the suffix.
Side-by-side result
| Input | Base reading | Bore reading | Suffix reading |
|---|---|---|---|
| 6205-ZZ | Deep-groove ball bearing, 62 series. | 05 means 25 mm bore. | ZZ means two metal shields. |
| 6203-2Z | Deep-groove ball bearing, 62 series. | 03 is a special code for 17 mm bore. | 2Z means two metal shields. |
ZZ and 2Z
Many catalogs use ZZ or 2Z to communicate shields on both sides, but the exact shield construction belongs to the manufacturer catalog. The decoder treats both as two metal shields and then tells you to verify the catalog entry.
Why the base number still rules
The shared shield meaning does not merge the two bearings. 6205 and 6203 have different bore codes, and catalog dimensions can differ even when the family and shield suffix look familiar. Read the suffix as an addition to the base number, not as a replacement for it.
Use case boundary
This comparison is useful for label reading, inventory cleanup, and search-query interpretation. It is not enough for substitution in a machine, because fit, outside diameter, width, load, speed, lubrication, and environmental requirements still need exact catalog data.
Source and limits
Sources: open-source bearing CSV tables from gumyr/cq_warehouse (Apache-2.0), plus NSK bearing designation guidance, JTEKT/Koyo bearing number tables, SKF designation guidance, ISO rolling bearing references including ISO 5753-1 for radial internal clearance, and ANSI/ABMA tapered roller bearing references; verified 2026-08-30.
- This content explains the imported bearing database first, then the parser fallback for supported patterns that are not in the exact table.
- Exact database rows preserve the imported dimensions and suffix notes, but they still do not replace the maker catalog for procurement, maintenance, or safety decisions.
- Bore code parsing does not decide outside diameter, width, cage material, lubrication, fit, load rating, or interchangeability.
- Metric tapered roller and inch-design tapered roller bearings use separate designation systems, so verify the exact catalog entry before purchase or maintenance work.
Related bearing guides
Bearing Seal, Shield, and Clearance Suffixes | Bearing Bore Code and Dimensions | 608-2RS Bearing Number