Bearing Designation Decoder

This bearing number decoder breaks an ISO bearing designation such as 6205-2RS C3 into its component fields — type, dimension series, bore, suffixes — so you can enrich a product record with structured, searchable attributes instead of one opaque part string. It is built for distributors and MRO catalog teams who receive bearings from dozens of suppliers and need consistent specs across every line.

Bearing Designation Decoder

Runs in your browser · no upload

Paste bearing designations, one per line

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Suffix letters are manufacturer-specific and only partly standardised; confirm substitutions against the maker's datasheet. See how Claro decodes part strings across a whole catalog →

What it checks

Paste a designation and the decoder parses and explains each segment of the code:

• Bearing type — the series code or prefix (for example 60/62/63 deep-groove ball, 72/73 angular contact, 12/22 self-aligning ball, 222/223 spherical roller, 302/322 tapered roller, 511 thrust ball, N/NU/NJ cylindrical roller).
• Dimension series — width/height series and diameter series that together set the outer diameter and width for a given bore. For the common deep-groove series 60, 62 and 63 the decoder also returns the outer diameter and width in mm.
• Bore code — the standard rule where bore codes 00, 01, 02, 03 map to 10, 12, 15, 17 mm, and codes from 04 upward are multiplied by 5 to give the bore in millimetres.
• Seal and shield suffixes — 2RS/2RSR (contact seals both sides), ZZ/2Z (metal shields), RS (one side), and open variants.
• Internal clearance — C2, CN, C3, C4 and similar codes that affect fit and running behaviour.
• Cage, precision, and heat-stabilisation suffixes — common modifiers (such as M, J, TN9, P6, P5, S1) that distinguish otherwise identical bore-and-series records. Lubrication and grease codes are too manufacturer-specific to decode reliably, so they are flagged rather than guessed.
• Format validity — whether the string is a plausible ISO designation or a manufacturer-specific code the parser cannot fully resolve.

How the bearing number decoder works

The tool applies the metric bearing designation system defined in ISO 15 (boundary dimensions) and ISO 76/ISO 355 conventions used across the industry. A designation is read left to right: the type and series prefix, then the two-digit bore code, then an ordered set of suffixes. The decoder uses the published bore-code arithmetic — fixed values for 00–03, then code x 5 from 04 up — and a lookup of common type, seal, and clearance suffixes to label each segment in plain language.

Because suffix conventions vary slightly between manufacturers, the decoder flags any segment it cannot confidently resolve rather than guessing. That is the same discipline you want in catalog enrichment generally: a value is only as trustworthy as the rule or source behind it. See data normalization for why consistent parsing matters before matching or publishing.

All processing happens client-side in your browser. Nothing is uploaded, stored, or sent to a server — paste a single code or a column of thousands and it stays on your machine. That makes it safe for pre-release supplier price files and confidential MRO catalogs.

How to read a bearing part number

A bearing designation has three parts: a basic designation (type, dimension series, bore), then optional supplementary suffixes. SKF describes the basic designation as exactly that, and says the bore size code multiplied by 5 gives the bore in millimetres. Timken’s catalog gives the same rule with the exceptions: codes 00, 01, 02 and 03 are 10, 12, 15 and 17 mm, and from 04 up the bore in mm is the code times 5.

Number	Type	Dimension series	Bore code	What the sources confirm
6205	6 = deep groove ball	2	05	Bore 25 mm; the manufacturers’ pages list 25 x 52 x 15 mm
6305	6 = deep groove ball	3	05	Same 25 mm bore as 6205; the series changes outside diameter and width, which you read from the maker’s table or the decoder
7205	7 = single-row angular contact ball	2	05	Bore 25 mm; SKF lists 7205 BEP as 25 x 52 x 15 mm with a 40 degree contact angle

The last two digits are the bore code for these examples. Letters after the number are not a standard: for 7205, SKF documents B as a 40 degree contact angle and E as an optimized internal design, while another maker may write the angle differently. Seal and shield suffixes differ by maker too: SKF 2RS1, FAG 2RSR, NSK DDU and NTN LLU are all contact-sealed designs, not identical products.

Example designation	Maker	Reading
6203-2RSH/C3GJN	SKF	Deep groove, 03 bore code, NBR contact seals both sides, C3 clearance, GJN grease
6205DDU	NSK	Deep groove 25 x 52 x 15 mm, rubber contact seals both sides
6205LLU	NTN	Deep groove 25 x 52 x 15 mm, contact seal, nitrile rubber
6207-2RSR	FAG	Deep groove 35 x 72 x 17 mm, contact seals both sides

Maker-by-maker detail with sources is in the bearing suffix reference, SKF specifics are in SKF bearing suffix codes, and the seal question is answered in what does 2RS mean on a bearing. The ball bearing attribute template lists the fields to store the parsed values in.

Sources (retrieved 12 October 2026): SKF basic bearing designation system; SKF 7205 BEP; SKF single row angular contact designation system; Timken deep groove ball bearing sell sheet; NSK 6205DDU; NTN 6205LLU; Schaeffler 6207-2RSR; SKF electric-motor handbook.

Related resources

FAQ

How do you read a bearing number like 6205? +

Read it left to right. The 6 is the type (deep-groove ball). The 2 is the dimension series, which sets the outer diameter and width band. The final 05 is the bore code: codes 00–03 map to 10/12/15/17 mm, and from 04 up you multiply by 5 — so 05 means a 25 mm bore.

What does 2RS or ZZ mean on a bearing? +

They are seal and shield suffixes. 2RS (sometimes 2RSR) means contact rubber seals on both sides, ZZ or 2Z means metal shields on both sides, and a single RS or Z means the closure is on one side only. Open bearings carry no such suffix.

What is bearing clearance C3? +

C3 is an internal radial clearance class greater than the standard (CN) clearance. Codes run roughly C2 (tighter) through C5 (looser). Higher clearance is often specified for press fits or applications that run hot, where the bearing expands in use.

Can I decode bearings in bulk for a catalog feed? +

Yes. Paste a whole column of designations and the decoder parses each row, returning bore, series, seal, and clearance as separate fields. Because it runs entirely in your browser, you can process large or confidential files without uploading anything.

Does decoding confirm two bearings are interchangeable? +

No. Matching designations is a strong signal, but interchangeability also depends on tolerance class, cage material, lubrication, and load rating. Use the decoder to standardize and compare records, then confirm any substitution against the manufacturer datasheet.

How do you read an angular contact bearing number like 7205? +

The 7 is the type (single-row angular contact ball bearing), the 2 is the dimension series and 05 is the bore code, which gives a 25 mm bore. The letters after it, such as B, BE or ACD, are maker-specific and often give the contact angle or internal design, so check the maker’s table.