RKB NNU 49/500 cylindrical roller bearing

RKB NNU 49/500 belongs to cylindrical 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 NNU 49/500 and any equivalents.

When a machine has to carry heavy radial loads and still hold its alignment, the RKB NNU line is one of the options our customers ask about most. These are double-row cylindrical roller bearings, and MR Industrial Accessories supplies them in a broad range of bore sizes. If you already know the part number, send it over and we will take it from there.

Reading the code is straightforward. NNU tells you the bearing has two inner rings and a flanged-free outer ring, with two rows of cylindrical rollers between them. The figure after the slash is the bore in millimeters, so NNU 40/500 takes a 500 mm shaft and NNU 40/530 takes a 530 mm shaft. Across the NNU 40 series the bore runs from 500 up to 750 mm, covering NNU 40/560, NNU 40/600, NNU 40/630, NNU 40/670, NNU 40/710 and NNU 40/750. These units normally come with a machined brass cage, and the outer ring can be supplied with lubrication grooves and holes to make regreasing easier.

Where do they fit? Gearboxes, rolling mills, paper machines, high-flow pumps, industrial fans and mining equipment are the usual homes for this design, along with machine tool spindles and large support rollers. The common thread is a need for rigidity: the bearing has to keep its position while radial forces push on it, and deformation has to stay minimal. Loads are mainly radial, though the bearing can handle a degree of combined loading.

Selection comes down to four things: the radial load, the running speed, the environment and the fit. Check that the supports are aligned and that internal clearance suits the application, because misalignment or the wrong clearance adds stress the bearing was not built for. Grease works for slower running; oil is the choice as speed rises. In dirty surroundings, add seals or oil seals to keep contamination out. During mounting, use the proper tools and avoid impacts that could mark the rollers or raceways.

RKB NNU bearings can be swapped with other brands that use the same designation and dimensions, provided tolerances, internal clearance and lubrication execution line up with the original. Send us the part number and we will confirm the equivalent. Quotes go out by WhatsApp or email, and we are glad to help you pick the right variant.