NJ2311 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the NJ2311 model number is decoded

The NTN order number NJ2311 denotes a 55×120×43 mm (2.165 × 4.724 × 1.693 in) cylindrical roller bearing in the NJ2300 family, a pressed sheet-steel cage. Reading the code: NJ for the one-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 55 mm (00–03 use the 10/12/15/17 exception table). the bare number is the standard-capacity open execution with the normal pressed-steel cage; the ＊ symbol printed before the number in 2203E marks the ULTAGE new-generation specification — upgraded material/geometry and longer rating life, not part of the order code; quote the full NJ2311 designation when purchasing. Mass 2130 g for the 55×120×43 mm NJ2311 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NJ2311 non-locating position preloads the bearing when the shaft grows.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 55 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting NJ2311.
• If the shaft must be located both ways, do not use NJ2311 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
• The 32.5 mm section at 55 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 43 mm-wide cavity.
• The NJ rib arrangement is not interchangeable with another prefix on the same 55 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 120×43 mm envelope matches.
• The 43 mm width and abutment faces must be square to the axis; a tilted spacer concentrates load across the roller set and shows as uneven raceway polish on the 55 mm inner ring.
• The 164/162 kN ratings, 19.8 kN Pu and 2130 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ2311 (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.