NTN NK120/40 needle roller bearing

NTN NK120/40 belongs to needle roller bearing, part of our Bearings range. Tell us how many you need by WhatsApp or email and we'll get back to you promptly with a quote for NK120/40 and any equivalents.

Needle roller bearings in the NTN NK series are single-row radial units supplied without an inner ring. Their low section height lets them carry substantial radial load in spots where room on the shaft and in the housing is tight, and the shaft itself serves as the raceway. You will find them in transmissions, pumps, compressors and production machinery that runs continuously.

Reading the code is straightforward. After NK come two figures split by a slash: the first is the bore or raceway diameter, the second is the overall width. So NK12/16 is a needle roller bearing with a 12 mm bore diameter and a 16 mm width. Because there is no inner ring, the shaft has to meet the required hardness and surface finish to work as a raceway. Suffixes used in this family cover sealing, internal clearance or special tolerance variants, and each one is read against the current NTN catalogue.

Typical installations include gearboxes, hydraulic pumps, air compressors, machine tools, packaging equipment and transmission lines, as well as automotive gearboxes and steering systems and agricultural machinery. The appeal is radial capacity within a very small envelope, which suits assemblies where the outer diameter cannot grow.

When selecting a size, look at the radial load, the rotation speed and the operating environment. If the shaft does not reach the necessary hardness, pair the bearing with a suitable inner ring. Fitting calls for precise alignment and proper lubrication, either grease for general duty or oil where the system circulates it. A side seal keeps contaminants out and lubricant in. Confirm internal clearance and shaft tolerance before mounting, and avoid impacts that could mark the needles or the cage.

Bearings that share the same dimensional designation can be interchanged across brands, provided bore diameter, outer diameter and width line up. Cage, sealing or tolerance may still differ, so it pays to check the application. If your part number comes from another brand, send it over and we will identify the matching equivalent and quote the exact part you need.

To get a quote on your NTN NK series bearing, message us the complete part number on WhatsApp or by email. We answer promptly and can also point you to other sizes in the series, or to needle roller bearings with an inner ring if your application calls for one.