51222-NTN bearing: complete specifications & equivalents
The 51222-NTN is a ISO 104 radial bearing sized 110 x 160 x 38 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 | 160 mm |
| Width B | 38 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 153 kN |
| Basic static load rating C0 | 450 kN |
| Fatigue load limit Pu | 17.5 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2460 g |
| Manufacturer designation | NTN 51222 |
| 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 & 51200-series range
| Bore d | 4.331 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.496 in |
| ISO bore code | 22 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 51200-series | 10 mm |
| Largest outer diameter in 51200-series | 520 mm |
| Width range across 51200-series | 11–112 mm |
| Bore position in 51200-series (smallest first) | 21 of 39 |
| Bore above smallest 51200-series size | 100 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 51222-NTN model number is decoded
From the medium-section 51200 thrust family, 51222 measures 110 mm through the shaft washer, 160 mm over the outside and 38 mm in assembled height. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); 22 encodes the 110 mm bore (bore code x 5). At 38 mm of height the stack is compact for the 110 mm bore class, trading section height for the medium-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 450 kN class figures at the cost of OD and height. After assembly, rotate under light load and check torque and temperature rise — a thrust ball bearing mounted with the washers swapped runs, but fails fast.
Typical equipment & failure modes
Common applications
- ship winch and capstan thrust shafts
- crusher main-shaft thrust supports
- large rotary-table and index-table thrust rings
- vertical water-pump and turbine thrust blocks
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
- 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 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 110 mm bore.
- The 1,200 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.
- A housing washer pressed tight in its seat cannot self-centre; the resulting eccentric running shows up as cage wear long before raceway fatigue.
- Below the minimum axial load the balls skid; the catalogue Ca of 153 kN never saves a bearing that is running too lightly loaded at 1,200 r/min.
- The Ca 153/C0a 450 kN ratings and 17.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51222; 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 51222?
51222 is a single-direction thrust ball bearing to ISO 104: 110 mm shaft-washer bore, 160 mm outside diameter, 38 mm stack height (4.331 x 6.299 x 1.496 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 153 kN, C0a 450 kN and a 17.5 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,800 r/min; mass about 2460 g.
How is the 51222 designation structured?
512 is the dimension series (medium-section 51200 thrust family); 22 encodes the 110 mm bore (bore code x 5). The 160 mm OD and 38 mm height follow the ISO 104 boundary plan for that series.
Can 51222 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 51222?
At the 1,200 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 51222?
The 110/160/38 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 153 kN / C0a 450 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.