N344 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 N344 model number is decoded

For pure radial duty on a 220 mm shaft NTN supplies N344: two integral ribs on the inner ring and a ribless separable outer ring; the open execution is rated 1,400 r/min on grease and 1,600 r/min on oil. On the NTN nameplate N states which ring carries the ribs, which determines whether N344 floats or locates; the numeric remainder is the ISO 15 series and 220 mm bore reference, not a fit or clearance instruction. NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of N344. Thermal planning around the 1,400 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 1,600 r/min for continuously high-duty 220 mm positions. Keep the open bearing wrapped until fitting: the line-contact raceways of the 220 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 220 mm bore, oil-lubricated arrangements toward 1,600 r/min need positive flow and drain design; the 71700 g N344 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
• Minimum radial load is frequently missed in oversized motor and fan selections: an underloaded N344 skids at 1,400 r/min and fails by smearing long before L10 fatigue.
• Do not replace N344 with a deep-groove ball bearing on rating alone: line contact gives 1320 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
• Do not replace N344 with a deep-groove ball bearing on rating alone: line contact gives 1320 kN radial capacity but the bearing cannot carry the thrust duty a ball bearing can and misalignment tolerance is only 3–4 arc-minutes.
• Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 460 mm race brinells and releases as vibration within hours.
• The 1320/1570 kN ratings, 133 kN Pu and 71700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for N344 (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.