NN3021 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 NN3021 model number is decoded

NN3021 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 105×160×41 mm ISO 15 envelope. On the NTN nameplate NN states which ring carries the ribs, which determines whether NN3021 floats or locates; the numeric remainder is the ISO 15 series and 105 mm bore reference, not a fit or clearance instruction. Minimum radial load matters: an unloaded NN3021 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Mass 2890 g for the 105×160×41 mm NN3021 execution covers the pressed-steel cage and full roller complement; substitute on mass plus rating, not envelope alone. Mount the separable inner ring + roller assembly on the shaft first and slide the outer ring into the housing; never press the outer ring through the rollers of NN3021.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Induction-heat the 105 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 160 mm raceway.
• The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 220/320 kN pair here belongs to NN3021 as printed, not to the bare size.
• Open NN3021 units need application-supplied sealing and a defined lubricant schedule; film thickness is the first failure mode for line contact when viscosity drops at the 105 mm contact.
• The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 220/320 kN pair here belongs to NN3021 as printed, not to the bare size.
• Do not replace NN3021 with a deep-groove ball bearing on rating alone: line contact gives 220 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 220/320 kN ratings, 36 kN Pu and 2890 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN3021 (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.