Cylindrical Roller Bearing have rollers which are essentially cylindrical in shape. This provides a modified line contact with the cylindrical inner and outer ring raceways, while the rollers are guided by ground ribs on either the inner or outer ring. The cylindrical shape allows the inner ring to have axial movement relative to the outer ring (except the NH type). This is especially important when accommodating thermal expansion when both rings must be press fitted. In this series, the NJ, NF and NH types can carry light or intermittent thrust loads. The NN3000 and NN3000K series are available in high precision tolerances and are well suited for use in machine tool spindles. NTN Cylindrical Roller Bearing, Series: NJ4, 30 mm Bore Dia, 90 mm Outside Dia, 1 Row, 23 mm W, Open Closure, 62500 N, Hardened Alloy Steel Bearing, Machined Brass Cage, 8500 RPM Maximum, -40 to 120 °C