51322 bearing: complete specifications & equivalents
The 51322 is a ISO 104 radial bearing sized 110 x 190 x 63 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 110 mm |
| Outer diameter D | 190 mm |
| Width B | 63 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 267 kN |
| Basic static load rating C0 | 705 kN |
| Fatigue load limit Pu | 25.9 kN |
| Limiting speed (mechanical) | 870 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7670 g |
| Manufacturer designation | NTN 51322 |
| 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 | 4.331 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 2.48 in |
| ISO bore code | 22 |
| Radial section height (D−d)/2 | 40 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) | 16 of 25 |
| Bore above smallest 51300-series size | 85 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51322-M | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 110×190×63 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 51322 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, 51322 appears as a heavy-section 51300 thrust family bearing with a 110 mm shaft washer, a 190 mm housing diameter and 63 mm of stack height. NTN builds the number from 513 is the dimension series (heavy-section 51300 thrust family); 22 encodes the 110 mm bore (bore code x 5). Flat-seat washers make the bearing tolerant of simple housings but demand square faces: the whole 267 kN rating assumes the load arrives truly axial. For a 110 mm shaft with combined radial-plus-axial load, pair this bearing with a separate radial bearing — the thrust ball bearing must never be asked to carry the radial share. The shaft washer (bore 110 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on.
Typical equipment & failure modes
Common applications
- vertical water-pump and turbine thrust blocks
- large crane hook and swivel assemblies
- rolling-mill screwdown and adjustment screws
- heavy press and forging-machine thrust seats
Known failure patterns
- ball and raceway smearing from gyroscopic spin when the bearing runs fast under too little axial load — the minimum-load rule exists exactly for this
- fretting between shaft washer and shaft when the seat is cut loose — the washer creeps, the centre line shifts and the balls start running off-track
- early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction
- washer face corrosion under long standstill in humid service, later printed into the raceway as evenly spaced pitting
- lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced
Selection pitfalls — read before you substitute
- At 110 mm bore the washers are heavy enough to sag out of square during assembly — support the stack horizontally where possible and verify face runout before loading.
- The 513 heavy section buys capacity with a larger 190 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.
- Swapping the shaft and housing washers is an easy assembly error on the 110 mm size — the bores differ only slightly, but the wrong pairing walks off-centre under load.
- The C0a of 705 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.
- Never substitute a double-direction bearing drawing part-for-part: the single-direction 51322 stack height of 63 mm and washer set differ from the double-direction execution.
- The Ca 267/C0a 705 kN ratings and 25.9 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51322; 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 51322?
51322 is a single-direction thrust ball bearing to ISO 104: 110 mm shaft-washer bore, 190 mm outside diameter, 63 mm stack height (4.331 x 7.48 x 2.48 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 267 kN, C0a 705 kN and a 25.9 kN fatigue load limit Pu; the grease limiting speed is 870 r/min and the oil rating 1,200 r/min; mass about 7670 g.
How is the 51322 designation structured?
513 is the dimension series (heavy-section 51300 thrust family); 22 encodes the 110 mm bore (bore code x 5). The 190 mm OD and 63 mm height follow the ISO 104 boundary plan for that series.
Can 51322 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 51322?
At the 870 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 51322?
The 110/190/63 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 267 kN / C0a 705 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.