NN3084 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 NN3084 model number is decoded

NN3084 is an NTN NN cylindrical roller bearing: two integral ribs on the outer ring and a ribless, separable inner ring — a non-locating bearing that lets the shaft float axially, inside the 420×620×150 mm ISO 15 envelope. On the NTN nameplate NN states which ring carries the ribs, which determines whether NN3084 floats or locates; the numeric remainder is the ISO 15 series and 420 mm bore reference, not a fit or clearance instruction. Line contact between rollers and raceways gives NN3084 high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. Mass 154000 g for the 420×620×150 mm NN3084 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. Keep the open bearing wrapped until fitting: the line-contact raceways of the 420 mm bore indent under a single hard particle, and the steel cage provides no sealing of its own.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 420 mm bore, oil-lubricated arrangements toward 990 r/min need positive flow and drain design; the 154000 g NN3084 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
• Do not replace NN3084 with a deep-groove ball bearing on rating alone: line contact gives 2300 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 150 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 420 mm inner ring.
• The 100.0 mm section at 420 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 150 mm-wide cavity.
• Wide (22/23) and light (10/49) executions at 420 mm bore share bore but not OD/width; check the full NN3000 series code before substituting, because housing and shoulder geometry will not interchange.
• The 2300/4300 kN ratings, 320 kN Pu and 154000 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3084 (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.