21308-E1-XL-K-C4 bearings have the advantages of Self-aligning, high load-bearing capacity, impact resistant, and adaptable to heavy loads, and are therefore widely used in the Gearboxes, drive shafts, conveying equipment, general machinery.

| Part Number | 21308-E1-XL-K-C4 |
| Design Type | E1 = without central rip |
| Bore Type | K = Tapered bore (K = taper 1:12) |
| RIC | C4 |
| X-Life | XL long life design |
| Row | 2 |
| Bearing Type | Double row spherical roller bearings |
| Manufacturer Part Code | 21308-E1-K-C4 |
| Original Code | 21308-E1-K |
| Cage | JPA = Stamping steel cage |
| Measurement | Metric |
| d φ Inside [inch] | 1.575 |
| D Φ Outside [inch] | 3.543 |
| B Width [inch] | 0.906 |
| nB Reference speed (grease) [min–1] | 5193 |
| nG Limiting speed (oil) [min–1] | 9526 |
| Weight [kg] | 0.702 |
| r(min.) Chamfer [inch] | 0.059 |
| D1 [inch] | 3.181 |
| d2 [inch] | 2.350 |
| ds [inch] | 0.126 |
| ns [inch] | 0.189 |
| Cr Radial Dynamic [lbf] | 24490 |
| C0r Radial static [lbf] | 24035 |
| Cur Radial Fatigue [lbf] | 3197 |
| Temperature - T(min)[°C] | -30 |
| Temperature - T(max)[°C] | up +200 |
| Mounting dimensions | |
| da(min.) [inch] | 1.929 |
| Da(max.) [inch] | 3.189 |
| ra(max.) [mm] | 0.702 |
| Calculation coefficient | |
| e | 0.24 |
| Y0 | 2.75 |
| Y1 | 2.81 |
| Y2 | 4.19 |
The 21308-E1-XL-K-C4 Double-row spherical roller bearings mainly consist of an inner ring, an outer ring, two rows of spherical rollers, a cage, and seals. The outer ring raceway has a spherical structure, while the inner ring has a double-row raceway. The rollers and raceways are logarithmically curved. The cage is typically made of stamped steel or machined brass.
Double-row spherical roller bearings possess excellent self-aligning properties, compensating for shaft deflection, installation errors, and misalignment. They can simultaneously withstand radial loads and bidirectional axial loads, exhibiting extremely high load-bearing capacity and strong impact resistance. Furthermore, the internal clearance can be optimized for vibration conditions, effectively reducing frictional temperature rise.















