Comparing with NKI series needle roller bearing, the heavy series NKIS needle roller bearings that have metric dimensions, larger outside diameter and heavier load capacity. The NKIS series is with inner rings, cage guided rollers, precision ground raceways with ribs, with/without seals are both available. The retainer guides needles providing full length roller contact for maximum capacity, low friction and long life.

When the needle roller bearing is impractical to finish the shaft to meet the desired raceway design requirements, an inner ring may be used. The metric series NKIS needle roller bearings are available with inner rings to form complete bearings. Bearings furnished with inner rings meet the quality requirements in accordance with ISO standards.

For NKIS series, there are two different structures for it based on if the bore is more than 7mm. The NKIS type bearings are used when the load carrying capacity or accuracy of drawn cup needle roller bearings with open ends is no longer sufficient and the high load capacity of cylindrical roller bearings is not yet required.  

Application

The needle roller bearing is used in various applications, such as automotive and truck transmissions, agricultural and construction equipment, pumps and compressors, and two-cycle engines, among others.