NUP234 bearing: complete specifications & equivalents
The NUP234 is a ISO 15 radial bearing sized 170 x 310 x 52 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 170 mm |
| Outer diameter D | 310 mm |
| Width B | 52 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 530 kN |
| Basic static load rating C0 | 635 kN |
| Fatigue load limit Pu | 59.5 kN |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 16700 g |
| Manufacturer designation | NTN NUP234 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
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.
Dimensions in inches & NUP200-series range
| Bore d | 6.693 in |
|---|---|
| Outer diameter D | 12.205 in |
| Width B | 2.047 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 70 mm |
| Smallest bore in NUP200-series | 17 mm |
| Largest outer diameter in NUP200-series | 580 mm |
| Width range across NUP200-series | 12–92 mm |
| Bore position in NUP200-series (smallest first) | 26 of 35 |
| Bore above smallest NUP200-series size | 153 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NUP234 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 NUP234 model number is decoded
For pure radial duty on a 170 mm shaft NTN supplies NUP234: the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring; the open execution is rated 2,200 r/min on grease and 2,500 r/min on oil. Reading the code: NUP for the two-direction-locating type, then the ISO 15 diameter/width series and the bore code — ×5 = 170 mm (00–03 use the 10/12/15/17 exception table). NTN prints two speed ceilings: 2,200 r/min grease and 2,500 r/min oil — the pressed-steel cage and lubricant film set the real limit at the 170 mm bore. Thermal planning around the 2,200 r/min grease ceiling should include the cage type (a pressed sheet-steel cage) and oil-flow option to 2,500 r/min for continuously high-duty 170 mm positions. Housing and shaft fillets must clear the ring chamfers of NUP234; an oversized radius locks the ring on its face and tilts the 52 mm-wide seat.
Typical equipment & failure modes
Common applications
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- electrical pitting on VFD-driven motor shafts without grounding protection
- edge loading from shaft deflection beyond the 3–4 arc-minute alignment limit
Selection pitfalls — read before you substitute
- At 170 mm bore, oil-lubricated arrangements toward 2,500 r/min need positive flow and drain design; the 16700 g NUP234 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Wide (22/23) and light (10/49) executions at 170 mm bore share bore but not OD/width; check the full NUP200 series code before substituting, because housing and shoulder geometry will not interchange.
- The 70.0 mm section at 170 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 52 mm-wide cavity.
- The 52 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 170 mm inner ring.
- If the shaft must be located both ways, do not use NUP234 alone: pair it with a locating bearing or specify the NUP execution with the matching loose rib ring from the 2203E table.
- The 530/635 kN ratings, 59.5 kN Pu and 16700 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NUP234 (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.
Frequently asked questions
What are the dimensions and catalogue data of NUP234?
NUP234 is an NTN NUP single-row cylindrical roller bearing to ISO 15: 170 mm bore, 310 mm OD and 52 mm width (6.693 × 12.205 × 2.047 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 530 kN, C0 635 kN, Pu 59.5 kN, grease limiting speed 2,200 r/min, oil 2,500 r/min, mass about 16700 g. It is open, with a pressed sheet-steel cage.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
The prefix states the rib arrangement: NU has two outer-ring ribs and a ribless inner ring (float, no axial load); NJ adds ribs for one-direction location; NUP adds a loose L-ring to locate both directions; N has two inner-ring ribs and a separable outer ring; NF has one rib per ring for one-direction guidance. NUP234 is the NJ rib arrangement plus a loose L-shaped rib ring on the inner ring — it locates the shaft in both axial directions.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NUP234 is supplied in the standard open execution shown in the table.
Can NUP234 take axial load and locate a shaft?
the NUP design provides two-direction axial location via its loose rib ring, for light/moderate thrust guidance. The loose rib ring still only suits light/short-duration axial guidance; heavy thrust belongs to a dedicated thrust bearing.
What do Fw and Ew mean for NUP234?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 208 mm, Ew 272 mm. The nominal bore/OD remain 170/310 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 2,200 r/min grease / 2,500 r/min oil.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.