51412 bearing: complete specifications & equivalents
The 51412 is a ISO 104 radial bearing sized 60 x 130 x 51 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 60 mm |
| Outer diameter D | 130 mm |
| Width B | 51 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 214 kN |
| Basic static load rating C0 | 435 kN |
| Fatigue load limit Pu | 19.7 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3120 g |
| Manufacturer designation | NTN 51412 |
| 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 & 51400-series range
| Bore d | 2.362 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 2.008 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 51400-series | 25 mm |
| Largest outer diameter in 51400-series | 300 mm |
| Width range across 51400-series | 24–120 mm |
| Bore position in 51400-series (smallest first) | 8 of 20 |
| Bore above smallest 51400-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51412-M | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per 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 51412 model number is decoded
51412 is an NTN single-direction thrust ball bearing of the extra-heavy 51400 thrust family: 60 mm bore, 130 mm outside diameter, 51 mm overall height in NTN Ball and Roller Bearings CAT.No.2203E. NTN builds the number from 514 is the dimension series (extra-heavy 51400 thrust family); 12 encodes the 60 mm bore (bore code x 5). The ball-and-cage set is separable from both washers, which is why the mounting order (shaft washer first, then cage, then housing washer) matters. For a 60 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. Mount the stack in order and confirm the shaft washer sits against its shoulder before loading: pressing through the balls brinells the raceway on the spot.
Typical equipment & failure modes
Common applications
- heavy press and forging-machine thrust seats
- ship winch and capstan thrust shafts
- crusher main-shaft thrust supports
- large rotary-table and index-table thrust rings
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
- 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
- rapid flaking after radial load was allowed onto the bearing — a single-direction thrust ball bearing carries axial load only
- lubricant starvation scoring on the raceway track when grease is thrown outward by centrifugal effect and never replaced
- 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 60 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 514 extra-heavy section is the top of the thrust-ball plan at this bore; beyond it the catalogue moves to spherical roller thrust bearings.
- Single-direction means exactly that: thrust on 51412 in the wrong direction separates the washers and drops the ball set — if reversal is possible even during coast-down, engineer against it.
- 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.
- Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51412 has no radial capacity at all.
- The Ca 214/C0a 435 kN ratings and 19.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51412; 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 51412?
51412 is a single-direction thrust ball bearing to ISO 104: 60 mm shaft-washer bore, 130 mm outside diameter, 51 mm stack height (2.362 x 5.118 x 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 214 kN, C0a 435 kN and a 19.7 kN fatigue load limit Pu; the grease limiting speed is 1,200 r/min and the oil rating 1,700 r/min; mass about 3120 g.
How is the 51412 designation structured?
514 is the dimension series (extra-heavy 51400 thrust family); 12 encodes the 60 mm bore (bore code x 5). The 130 mm OD and 51 mm height follow the ISO 104 boundary plan for that series.
Can 51412 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 51412?
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 51412?
The 60/130/51 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 214 kN / C0a 435 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.