NU406 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 NU406 model number is decoded

For pure radial duty on a 30 mm shaft NTN supplies NU406: two integral ribs on the outer ring and a ribless, separable inner ring; the open execution is rated 7,300 r/min on grease and 8,500 r/min on oil. On the NTN nameplate NU states which ring carries the ribs, which determines whether NU406 floats or locates; the numeric remainder is the ISO 15 series and 30 mm bore reference, not a fit or clearance instruction. Line contact between rollers and raceways gives NU406 high radial capacity but no tolerance for misalignment: beyond roughly 3–4 arc-minutes the roller ends edge-load and fatigue accelerates. Speed ratio check: limiting 7,300 r/min is .86 of the 8,500 r/min oil value for NU406; grease-churn heating closes that gap as fill quantity rises. Heat the inner ring to max 120 °C for the 30 mm interference fit and support the ring face square during fitting; cocking over a keyway brinells the raceway before first rotation.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 30 mm bore, shaft thermal growth can preload the inner ring if the fit is too tight; verify residual interference at temperature and confirm the float ring still slides after mounting NU406.
• The 23 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 30 mm inner ring.
• The EA high-capacity roller complement changes the load figure versus the basic execution of the same number; the 69.5/55 kN pair here belongs to NU406 as printed, not to the bare size.
• Wide (22/23) and light (10/49) executions at 30 mm bore share bore but not OD/width; check the full NU400 series code before substituting, because housing and shoulder geometry will not interchange.
• Wide (22/23) and light (10/49) executions at 30 mm bore share bore but not OD/width; check the full NU400 series code before substituting, because housing and shoulder geometry will not interchange.
• The 69.5/55 kN ratings, 6.7 kN Pu and 732 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NU406 (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.