The SKF 6308-2RS1/C3 is a single row deep groove ball bearing with a 40 mm bore, 90 mm outside diameter and 23 mm width, fitted with a contact rubber seal on both sides (2RS1) and C3 radial internal clearance. It belongs to the SKF Explorer performance class and, per SKF, carries a basic dynamic load rating of 42.3 kN and a basic static load rating of 24 kN.
The designation can be read directly: 6 = single row deep groove ball bearing, 3 = ISO dimension series 03 (medium), a heavier cross-section with larger balls for higher loads on the same shaft size; 08 = bore code for 40 mm (08 x 5); 2RS1 = contact seals on both sides; C3 = radial internal clearance greater than normal.
The contact seals rub lightly on the inner ring, which keeps grease in and dust, water and washdown spray out better than a shield. The price of that protection is speed: SKF lists a limiting speed of 5,000 r/min for this sealed version, against 8,500 r/min for the shielded 6308-2Z/C3.
Technical data
| SKF designation | 6308-2RS1/C3 |
|---|---|
| Bearing type | Single row deep groove ball bearing |
| Dimension series | 63 – ISO dimension series 03 (medium) |
| Bore diameter (d) | 40 mm |
| Outside diameter (D) | 90 mm |
| Width (B) | 23 mm |
| Basic dynamic load rating (C) | 42.3 kN |
| Basic static load rating (C0) | 24 kN |
| Limiting speed | 5,000 r/min |
| SKF performance class | SKF Explorer |
| Sealing | Seal on both sides (contact) |
| Radial internal clearance | C3 (greater than normal) |
| Cage | Sheet metal (pressed steel) |
| Bore type | Cylindrical |
| Lubricant | Grease, no relubrication feature |
| Material | Bearing steel |
| Net weight | 0.63 kg |
| Condition | New, original SKF |
Typical applications
- Heavier electric motors and generators
- Belt and roller conveyors exposed to dust
- Pumps and mixers in damp or dusty plant rooms
- Construction and quarry equipment auxiliaries
- Like-for-like replacement of a worn SKF 6308-2RS1/C3
Compatibility and replacement
Every 6308 bearing made to ISO 15 has the same 40 x 90 x 23 mm boundary dimensions, so this bearing fits wherever a 6308 with contact seals and C3 clearance from another maker was used. Suffixes differ between brands: shields are often marked ZZ or 2Z, contact seals 2RS, 2RS1, DDU or LLU, and the clearance C3 may appear as “C3” or “/C3”. Always match the sealing arrangement and the clearance class shown on the old bearing; if your machine needs the other closure, the 6308-2Z/C3 is the same size.
Frequently asked questions
What is the difference between 6308-2RS1/C3 and 6308-2Z/C3?
Only the closures. The 6308-2Z has non-contact steel shields; the 2RS1 version has contact rubber seals. Per SKF, the limiting speed is 8,500 r/min for 2Z and 5,000 r/min for 2RS1; the load ratings are the same. Choose shields for speed and low friction, seals for dirt and moisture.
Which shaft and housing does it fit?
A 40 mm shaft seat and a 90 mm housing bore, with 23 mm of axial space. The exact fit tolerances depend on the load and on which ring rotates, so follow the machine drawing or the old bearing seat.
What do the load ratings mean in practice?
The basic dynamic load rating C (42.3 kN) is used to calculate rating life: under ISO 281, a ball bearing loaded at one tenth of C has a basic rating life of 1,000 million revolutions. The static rating C0 (24 kN) is the reference for heavy loads at very low speed or standstill.
Related parts
- SKF 6308-2Z/C3 (shielded version)
- SKF 6307-2RS1/C3 (35 mm bore)
- SKF 6309-2RS1/C3 (45 mm bore)
- All SKF 6300 Series Bearings
Part of the SKF 6300 series stocked by RendatSP for electric motors, gearboxes, pumps, fans, conveyors and general industrial machinery, with fast shipping to Iraq, Saudi Arabia, UAE, Egypt, Yemen, Libya and across the Middle East and Africa.
Every part RendatSP supplies is new and original, carries a 1-year warranty and ships worldwide by air in 5 to 7 days once ready (shipping, payment and warranty). Send us the part number and quantity on WhatsApp or through the inquiry form and we will quote the same working day. Agents in Saudi Arabia, Iraq, the UAE, Egypt, Oman, Libya, Morocco, Mauritania, Yemen, Algeria and Jordan.
