31330XU 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 31330XU model number is decoded

The NTN 2203E table prints 31330XU in the steep-angle 31300 family for high axial load share: 150 mm bore, 320 mm cup OD, 82 mm T, with a grease limiting speed of 1,200 r/min and an oil-lubricated ceiling of 1,600 r/min. The last two digits 30 are the ISO bore code, ×5 = 150 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 82 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. At 860 kN C the bearing offers about 5.7 kN of dynamic capacity per millimetre of the 150 mm bore — compare any substitution on this ratio and the 82 mm assembled T, not on bore alone. The 5.7 kN-per-mm-bore capacity figure for 31330XU summarises the 860 kN rating over 150 mm bore; use it to sanity-check an interchange candidate before swapping brands. Mount the 150 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 31330XU.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 150 mm bore the 31330XU set is adjusted with hydraulic nuts on large mill and wind positions; follow the drive-up angle/end-play procedure, because manual torque methods cannot control preload at the 860 kN C level.
• The steeper contact angle of the steep-angle 31300 family for high axial load share raises axial capacity but lowers the speed ceiling against a 302/322 bearing at 150 mm bore; do not swap to the lighter family without re-checking the 1,200 r/min grease limit and the thrust load split.
• On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 150 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
• Do not confuse T (82 mm assembled width of cone + cup) with the cone width when drawing spacers; an abutment sized to T instead of the ring width leaves the cup unseated.
• Open 31330XU units have no seals: a wheel-hub or gearbox application needs external sealing or the 1,200 r/min grease figure is meaningless once water reaches the cone rib.
• The 860/1030 kN ratings and 97.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 31330XU (ISO 355 7GB); internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.