NN 3068 ASK.M.SP bearings ( 340 mm x 520 mm x 133 mm) have the advantages of Extremely high rotational accuracy and rigidity, high rotational speed and low heat generation, suitable for high-speed and high-positioning-precision applications, and are therefore widely used in the Machine tool spindles, high-speed motors, precision rolling mills, industrial robots, and aerospace equipment.

| Part Number | NN 3068 ASK.M.SP |
| Reference From | FAG NN 3068 ASK.M.SP |
| Series | NN30..-AS-K-M-SP |
| Bearing Type | Cylindrical roller bearing, double row, separable, with cage (Non-locating bearings) |
| Design Type | NN = ribs on inner ring, outer ring without ribs |
| Dimension series | 30 (Medium series) |
| Bore Type | K = Tapered (taper 1:12) |
| Cage | M = Brass cage, guided by rollers |
| Rows NO. | Double row |
| Radial internal clearance | C1 |
| Accuracy class | SP = Super Precision |
| External form | AS = Lubricating groove and holes on the outer ring |
| Weight [lb] | 218.917 |
| Cr Radial Dynamic [lbf] | 366387 |
| C0r Radial static [lbf] | 730525 |
| Cur Radial Fatigue [lbf] | 68531 |
| nB Reference speed [rpm] | 1351 |
| nG Limiting speed [rpm] | 1669 |
| d φ Inside [inch] | 13.386 |
| D Φ Outside [inch] | 20.472 |
| B Width [inch] | 5.236 |
| r(min.) [inch] | 0.197 |
| s [inch] | 0.343 |
| E [inch] | 18.622 |
| d1 [inch] | 16.102 |
| ds [inch] | 0.374 |
| ns [inch] | 0.697 |
| Mounting dimensions | |
| da(h12) [inch] | 14.055 |
| Da(H12) [inch] | 19.803 |
| Db(min.) [inch] | 18.779 |
| ra(max.) [inch] | 0.157 |
The NN 3068 ASK.M.SP Ultra-precision cylindrical roller bearings are primarily composed of high-precision inner and outer rings (made of precision-ground bearing steel), cylindrical rollers (graded to P4 or higher precision), and a cage (solid brass or outer ring guided type). Common structures include the N10 series (double-flange outer ring, no flange inner ring) and the NN30 series (double-row structure), with the rollers and raceways employing a logarithmic curve profile design.
Ultra-precision cylindrical roller bearings exhibit extremely high radial stiffness, making them suitable for precision spindles requiring heavy loads and high rigidity. They offer high limiting speeds, and optimized roller end face and flange contact reduce friction and heat generation. Precision grades can reach P4 to P2, providing smooth rotation and low vibration. They can be used as floating end bearings to compensate for thermal expansion and maintain high positioning accuracy.















