51332 bearing: complete specifications & equivalents
The 51332 is a ISO 104 radial bearing sized 160 x 270 x 87 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 160 mm |
| Outer diameter D | 270 mm |
| Width B | 87 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 450 kN |
| Basic static load rating C0 | 1470 kN |
| Fatigue load limit Pu | 45 kN |
| Limiting speed (mechanical) | 600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 20700 g |
| Manufacturer designation | NTN 51332 |
| Standard | ISO 104 |
| 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 & 51300-series range
| Bore d | 6.299 in |
|---|---|
| Outer diameter D | 10.63 in |
| Width B | 3.425 in |
| ISO bore code | 32 |
| Radial section height (D−d)/2 | 55 mm |
| Smallest bore in 51300-series | 25 mm |
| Largest outer diameter in 51300-series | 340 mm |
| Width range across 51300-series | 18–110 mm |
| Bore position in 51300-series (smallest first) | 21 of 25 |
| Bore above smallest 51300-series size | 135 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51332-M | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 160×270×87 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 51332 model number is decoded
At 160 x 270 x 87 mm, NTN 51332 sits in the heavy-section 51300 thrust family of the single-direction thrust programme. Reading the code: 513 is the dimension series (heavy-section 51300 thrust family), and 32 encodes the 160 mm bore (bore code x 5). At 87 mm of height the stack is compact for the 160 mm bore class, trading section height for the heavy-section load level. Within the thrust-ball plan, 511 is the light section and 514 the heaviest for a given bore; moving up a series raises the C0a from 1470 kN class figures at the cost of OD and height. On a vertical shaft, pack grease between the washers and plan a relubrication path — centrifugal effect drives grease outward and the track runs dry without it.
Typical equipment & failure modes
Common applications
- large marine winch and windlass shafts
- heavy press and mill screwdown thrust seats
- crane slew-ring auxiliary thrust positions
- large mixer and reactor vertical shafts
Known failure patterns
- cage pocket wear and ball skid polish after long running below the minimum axial load, the balls sliding instead of rolling on the washers
- housing-washer rocking on an out-of-square support face, seen as uneven wear around the raceway circle and rising running torque
- rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only
- contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats
- edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track
Selection pitfalls — read before you substitute
- For a 160 mm bore thrust bearing, the seating surfaces and oil supply decide service life; at this size a field-improvised housing is the usual root cause behind "premature" failures.
- The 513 heavy section buys capacity with a larger 270 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.
- Single-direction means exactly that: thrust on 51332 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.
- Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.
- Below the minimum axial load the balls skid; the catalogue Ca of 450 kN never saves a bearing that is running too lightly loaded at 600 r/min.
- The Ca 450/C0a 1470 kN ratings and 45 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51332; raceway geometry legitimately differs between manufacturers, so re-verify ratings and washer identification before substituting another make.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 51332?
51332 is a single-direction thrust ball bearing to ISO 104: 160 mm shaft-washer bore, 270 mm outside diameter, 87 mm stack height (6.299 x 10.63 x 3.425 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 450 kN, C0a 1470 kN and a 45 kN fatigue load limit Pu; the grease limiting speed is 600 r/min and the oil rating 860 r/min; mass about 20700 g.
How is the 51332 designation structured?
513 is the dimension series (heavy-section 51300 thrust family); 32 encodes the 160 mm bore (bore code x 5). The 270 mm OD and 87 mm height follow the ISO 104 boundary plan for that series.
Can 51332 carry radial load or reversing thrust?
No. The raceways contact the balls at 90 deg to the shaft, so the rating is purely axial and single-direction. Radial load must be carried by a separate radial bearing, and reversing thrust needs a second thrust bearing or a double-direction execution.
Why does NTN specify a minimum axial load for 51332?
At the 600 r/min class speed, centrifugal and gyroscopic effects make an under-loaded ball set skid and smear instead of roll. The catalogue minimum-load formula gives the axial preload — from the machine weight, springs or a dead-weight — that keeps the contact rolling.
What should be checked before substituting another make for 51332?
The 160/270/87 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 450 kN / C0a 1470 kN, the speed figures and the shaft/housing washer identification against the donor catalogue.
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.