Cylindrical Roller Bearings
Single-row cylindrical roller bearings of the NU series — NU204EM, NU2234 and NU316 — line-contact rollers for heavy radial duty.
Cylindrical roller bearings · NU204EM / NU2234 / NU316
Line contact for radial load
A cylindrical roller meets its raceway along a line, not a point, and that contact geometry is the family's reason to exist: heavy radial load carried on a stiff, compact bearing. The NU construction has two ribs on the outer ring and a plain inner ring, so the inner ring separates for fitting and the bearing accommodates axial float of the shaft. Gearboxes, motors and machine shafts are the natural homes of the type, and the line sits inside the needle roller family alongside the other roller lines.
| Model | Line position |
|---|---|
| NU204EM | NU series cylindrical roller bearing |
| NU2234 | NU series cylindrical roller bearing |
| NU316 | NU series cylindrical roller bearing |
NU construction and shaft float
The separable NU form earns its place where a shaft grows and shrinks with temperature: the rollers and cage stay with the outer ring in the housing while the inner ring rides the shaft, and small axial movement between them is the design working, not wear. Specifying the construction matters as much as the size — a buyer converting from a deep groove position to a cylindrical one for load reasons should say the conversion is happening, because the seating and the float arrangement change with it. The steel ball bearing family remains the answer where the float must be located rather than freed.
Cylindrical rollers beside needle rollers
Both lines carry radial load on rollers, and the difference is proportions: needle rollers are long and thin, packing high capacity into a small radial envelope, often without an inner ring at all; cylindrical rollers are shorter and fuller, running in a complete bearing with both rings. A drawn-cup needle position and an NU position are not substitutes. If the old drawing names an NU code, order the NU; if it names a needle assembly, the needle family is the answer. Codes convert within their own families, not across them.
Specifying an NU item
State the full NU code and the quantity; the code carries the bore, the series and the construction. Internal clearance is the second line of the specification where the duty fixes it, and cage material the third where the design names one. If the bearing is one of a shaft pair — a locating bearing at one end and the NU floating at the other is the classic arrangement — say so, and list the locating partner on the same inquiry so the pair is priced as a pair.
The suffix letters in an NU code carry the internal design, so a code copied without its suffix is an incomplete order. Quote codes whole, exactly as they stand on the drawing or the old bearing, and the design supplied is the design specified.
Send an inquiry
Give the full NU code for each cylindrical roller bearing on your list, with clearance, quantities and the destination market, through the inquiry form.