NN4948 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 NN4948 model number is decoded

NN4948 is the extra-light (10/49) section of the NTN NN4900 dimension series for a 240 mm shaft — 680 kN of basic dynamic capacity in a 16400 g, open bearing. Digit by digit, NN4948 reads as NN (double row, ribbed inner ring, separable outer), ISO 15 series, and bore 240 mm; trailing letters such as EA or E mark the cage/capacity execution and are part of the order number. Minimum radial load matters: an unloaded NN4948 at high speed skids its rollers and smears the raceway; spring preload or the rotor weight typically covers the requirement in motors and pumps. Thermal planning around the 1,700 r/min grease ceiling should include the cage type (a machined or stamped steel cage per the precision execution) and oil-flow option to 2,000 r/min for continuously high-duty 240 mm positions. Housing and shaft fillets must clear the ring chamfers of NN4948; an oversized radius locks the ring on its face and tilts the 80 mm-wide seat.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 240 mm bore, oil-lubricated arrangements toward 2,000 r/min need positive flow and drain design; the 16400 g NN4948 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
• Double-row NN precision bearings are typically ordered P5/P4 with specific radial clearance for spindle preloading; a P0/CN NN4948 does not substitute a precision-class execution.
• Wide (22/23) and light (10/49) executions at 240 mm bore share bore but not OD/width; check the full NN4900 series code before substituting, because housing and shoulder geometry will not interchange.
• Wide (22/23) and light (10/49) executions at 240 mm bore share bore but not OD/width; check the full NN4900 series code before substituting, because housing and shoulder geometry will not interchange.
• Do not replace NN4948 with a deep-groove ball bearing on rating alone: line contact gives 680 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 680/1410 kN ratings, 126 kN Pu and 16400 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NN4948 (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.