NACHI NU205C3 NU Cylindrical Roller Bearing 25x52x15 mm, C3

The NACHI NU205C3 is a single row cylindrical roller bearing in NU configuration: two flanges on the outer ring and none on the inner ring. It measures 25 x 52 x 15 mm (bore x outer diameter x width), with a basic dynamic load rating of 17,700 N and a basic static load rating of 15,700 N.

The inner ring and roller set can be separated from the outer ring. It does not take axial load and is used as a float (free) end bearing. Its radial internal clearance is C3 (35 to 60 µm).

Where this product is used

• Electric motors and generators
• Gearboxes and industrial transmissions
• Pumps, fans and compressors
• Machine tools and general industrial machinery
• Conveyor drives and other heavy rotating equipment

Features

• NU configuration, with two flanges on the outer ring and none on the inner ring. The inner ring and roller set can be separated from the outer ring.
• No axial location: does not take axial load, used as a float (free) end bearing
• Line contact between rollers and raceways gives a high radial load capacity for the size: Cr 17.7 kN, Cor 15.7 kN
• C3 radial internal clearance, larger than Normal (35 to 60 µm for a 25 mm bore)

Key specifications

Selecting the right option

The NU configuration has two flanges on the outer ring and none on the inner ring, so the inner ring and roller set can slide axially in the outer ring. That suits the float (free) end of a shaft, where it takes up thermal expansion, but it does not take axial load. If the bearing must locate the shaft axially, you need a type with a flange on both rings (see Related products).

C3 radial internal clearance is larger than Normal. The catalogue recommends C3 or larger where the inner ring runs hotter than the outer ring or the shaft deflects a lot. Interference fits also reduce the working clearance, so check it for your fits and operating temperatures.

Fitting and use

Check the load and speed against the catalogue figures before ordering and apply a suitable safety factor. Cylindrical roller bearings are mainly for radial load: any axial load must be well within what the flanges can carry by sliding contact, and the limit depends on lubrication and speed as well as the bearing.

The catalogue limiting speeds are for machined-cage bearings; for a pressed steel cage multiply them by 0.8. Pressed steel is the catalogue standard cage for these sizes, so the Model Details show both figures for each size.

These bearings are open: the housing arrangement has to supply and hold the lubricant and keep contamination out. Fit the rings with the housing and shaft tolerances recommended for your application, and keep the shaft and housing seats clean and square.

If you are replacing a bearing, check the full number stamped on it, including any letters after the digits, and send AIMS the number or the dimensions if you are not sure.

Related products

More sizes in the same configuration: NACHI NU cylindrical roller bearings (23 sizes) and NACHI NU C3 cylindrical roller bearings (15 sizes). Other configurations: NACHI NJ C3 cylindrical roller bearings (12 sizes) and NACHI N C3 cylindrical roller bearings (8 sizes). For combined radial and axial loads on one bearing, see the NACHI tapered roller bearings (metric series).