NJ2318 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 NJ2318 model number is decoded

The NTN order number NJ2318 denotes a 90×190×64 mm (3.543 × 7.48 × 2.52 in) cylindrical roller bearing in the NJ2300 family, a pressed sheet-steel cage. Digit by digit, NJ2318 reads as NJ (inner ring two ribs + one outer rib), ISO 15 series, and bore 90 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. NTN prints the raceway diameters for this size — Fw 115 mm and Ew 165 mm — the envelope inside the 90/190 mm bore/OD where the rollers actually run. Equivalent-load planning treats NJ2318 as a pure radial bearing: keep P below 360 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. After mounting verify the outer ring slides axially by hand at ambient temperature; a stuck float ring in a NJ2318 non-locating position preloads the bearing when the shaft grows.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Induction-heat the 90 mm inner ring (max 120 °C) and mount it before fitting the outer ring; the ring mass makes square guidance essential — driving through the rollers brinells the 190 mm raceway.
• Do not replace NJ2318 with a deep-groove ball bearing on rating alone: line contact gives 360 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
• The 64 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 90 mm inner ring.
• Wide (22/23) and light (10/49) executions at 90 mm bore share bore but not OD/width; check the full NJ2300 series code before substituting, because housing and shoulder geometry will not interchange.
• The NJ rib arrangement is not interchangeable with another prefix on the same 90 mm seat: inner ring two ribs + one outer rib. Swapping NU for NJ changes axial location behaviour even though the 190×64 mm envelope matches.
• The 360/395 kN ratings, 43.5 kN Pu and 7790 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ2318 (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.