Double Row Cylindrical Roller Bearings
Two rows of rollers in one pair of rings, giving very high radial rigidity in a compact width. Most executions have a tapered bore so the radial internal clearance can be set precisely by how far the inner ring is driven up the shaft taper. SES holds the range as an authorised SKF distributor, covering bore range About 30 mm to 500 mm; series NN30 K and NNU49 K families; bore taper 1:12 on K designations; precision classes Normal through P5 and finer. Executions include NN30 k series with tapered bore, NNU49 k series with tapered bore, cylindrical bore executions, super-precision executions, among others. It is specified most often into machine tool and grinding spindle front bearings and rolling mill roll neck positions on smaller stands. Every part is genuine SKF through official channels, with designation, specification and options confirmed against your duty before it ships — supplied from Kolkata and our branch network, with breakdown cover that does not sit in an inbox.
Send an enquiry
Check Price & Availability.
Give us the size or the failed part — we reply on WhatsApp.
Trusted across Metals & Energy
Supplying India’s Industrial Names.
From integrated steel plants to power utilities and EPC majors — the works that cannot afford a counterfeit part specify through SES.
Load
Very high radial, no axial location
Rigidity
High, suited to precision spindles
Bore
Usually tapered 1:12 for clearance setting
Clearance
Adjusted on mounting, measured not guessed
Where it runs.
You will find Double Row Cylindrical Roller Bearings in the parts of a plant where this particular duty actually occurs. In practice that means machine tool and grinding spindle front bearings, rolling mill roll neck positions on smaller stands, precision boring and milling machine spindles, and equally vertical lathe and turning table bearings, gear cutting machine work spindles, heavy indexing and rotary table assemblies. What links them is the duty rather than the machine name — load: Very high radial, no axial location. If your installation is not on that list it matters less than you would think: the operating condition decides the specification. Send us the load, the speed, the running temperature and the environment it runs in, and we will match it to the right execution in the SKF range and confirm what is in stock.
Specify it against the duty.
Specification here follows the operating condition, not the catalogue. The spindle must hold a tight running accuracy under load — A precision class double row bearing with a light negative clearance set on drive-up, since any residual clearance shows up as run-out at the tool. The shaft has a machined taper seat already — The tapered bore version, using the taper directly instead of adding a sleeve that introduces another interface. Axial location is required as well as radial support — A separate thrust bearing in the same assembly. This type carries no axial load and the shaft would simply drift. Where two of those apply at once, specify for the harsher of the two — under-specifying is what puts the part back on the bench a month later. Send us the duty and we will confirm the execution.
Ordering this from SES.
On tapered bore double row bearings, radial clearance is the adjustment. Measure it with a feeler gauge at the unloaded top roller before and during drive-up, and write both figures into the machine history sheet.