Every major manufacturer makes the same bearing: a deep groove ball bearing with a sheet-steel reinforced rubber seal on both sides. Each writes it differently. 2RS1 is SKF, 2RSR is FAG, DDU is NSK, LLU is NTN and 2NSE is NACHI — and because purchasing systems match on the code rather than the construction, these five get treated as five different parts.
Each manufacturer built its own suffix system before any of them were standardised, and ISO never harmonised seal designations — only boundary dimensions and tolerance classes. The result is a set of codes that mean the same thing but cannot be decoded from first principles. A buyer reading 2RS1 has to know it is SKF, or look it up.
Boundary dimensions always match: a 6205-2RS1 and a 6205DDU are both 25 × 52 × 15 mm and carry similar dynamic ratings. What does not automatically match is everything the seal implies.
State the full designation including clearance and any special suffix, plus the application speed and temperature. If the original is an SKF 2RS1/C3 and the alternative is an NSK DDU, the seal is equivalent but the clearance has to be written explicitly — NSK's default is CN, not C3. That single omission is the most common cause of a cross-brand substitution running hot.
| 2RS1 | SKF — contact seal, sheet-steel reinforced |
|---|---|
| 2RSH / RSH | SKF — heavier reinforced seal, common on larger bores |
| 2RSR | FAG / Schaeffler — contact rubber seal, both sides |
| DDU | NSK — contact rubber seal, both sides |
| LLU | NTN — contact rubber seal, both sides |
| 2NSE | NACHI — contact rubber seal, both sides |
| 2RS | KOYO, TIMKEN, INA and most Chinese manufacturers |
| Interchange basis | Boundary dimensions (d × D × B) and load rating |
| Brand | Code | Construction | Notes |
|---|---|---|---|
| SKF | 2RS1 | Rubber seal, sheet-steel reinforced | The reference designation |
| SKF | 2RSH | Heavier reinforced lip | Used on larger bore sizes |
| FAG / Schaeffler | 2RSR | Rubber seal, both sides | Equivalent duty to 2RS1 |
| NSK | DDU | Rubber seal, both sides | Default clearance CN |
| NTN | LLU | Rubber seal, both sides | LLB is the non-contact version |
| NACHI | 2NSE | Rubber seal, both sides | 2NSL is the non-contact version |
| KOYO / JTEKT | 2RS | Rubber seal, both sides | Same as 2RS1 in practice |
| TIMKEN / INA | 2RS | Rubber seal, both sides | Specify clearance separately |
A deep groove ball bearing is a single-row rolling bearing in which a ring of balls runs in deep raceway…
Read →This category covers everything outside the standard catalogue: thin-section and miniature bearings,…
Read →A self-aligning ball bearing carries two rows of balls running on a common sphered raceway in the outer…
Read →An angular contact ball bearing has its raceways offset so that the line joining the contact points crosses…
Read →Bearing accessories are the mounting and locating components that make a bearing work in a real machine:…
Read →Rubber contact seal on both sides — maximum protection
Read →Steel shield on both sides — high speed, coarse dust only
Read →Non-contact rubber seal — shield friction, better sealing
Read →No seal — maximum speed, relubrication access
Read →SKF's reinforced contact seal for larger bores
Read →FKM and PTFE seals for 150–260 °C
Read →Functionally yes. 2RS1 is SKF's designation for a contact rubber seal reinforced with sheet steel; 2RS is the generic form used by most other makers. Both mean two contact seals.
It is a design variant number, not a count of seals. Both sides are sealed. SKF uses the 1 to distinguish this seal generation from earlier versions.
Yes on dimensions and duty. Check the clearance suffix and the grease temperature range before you do — those are where substitutions actually fail.
2RSH is the heavier of the two and is used on larger sizes where a plain lip would deform. For a 6205 either works; for a 22220 the RSH family is the correct choice.
Send the designation, the three dimensions and the quantity — we reply with price, brand options and lead time within 30 minutes on working days.