51114 bearing: complete specifications & equivalents
The 51114 is a ISO 104 radial bearing sized 70 x 95 x 18 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 70 mm |
| Outer diameter D | 95 mm |
| Width B | 18 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 43 kN |
| Basic static load rating C0 | 127 kN |
| Fatigue load limit Pu | 5.7 kN |
| Limiting speed (mechanical) | 2400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 356 g |
| Manufacturer designation | NTN 51114 |
| 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 & 51100-series range
| Bore d | 2.756 in |
|---|---|
| Outer diameter D | 3.74 in |
| Width B | 0.709 in |
| ISO bore code | 14 |
| Radial section height (D−d)/2 | 12.5 mm |
| Smallest bore in 51100-series | 10 mm |
| Largest outer diameter in 51100-series | 640 mm |
| Width range across 51100-series | 9–85 mm |
| Bore position in 51100-series (smallest first) | 15 of 46 |
| Bore above smallest 51100-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51114-SKF | 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 51114 model number is decoded
The light-section 51100 thrust family entry 51114 stacks a shaft washer, ball-and-cage set and housing washer into 18 mm of height over a 70 mm bore. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 14 encodes the 70 mm bore (bore code x 5). NTN prints 43 kN axial dynamic and 127 kN axial static for this size and a 5.7 kN fatigue load limit Pu. Choose the light-section 51100 thrust family when the shaft carries pure thrust in one direction at moderate speed — vertical shafts are the textbook case. 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 rotary-table and index-table thrust rings
- vertical water-pump and turbine thrust blocks
- large crane hook and swivel assemblies
- rolling-mill screwdown and adjustment screws
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
- early fatigue from thrust reversal hammering the unloaded raceway, because the bearing has no contact surfaces for the opposite direction
- 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
- At 70 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 511 light section is the speed-friendly end of the thrust-ball plan — for the same 70 mm bore it gives up load to gain OD, height and limiting-speed headroom.
- Radial load is the silent killer here: a belt pull or gear force on the same shaft must land on a radial bearing, because 51114 has no radial capacity at all.
- The C0a of 127 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.
- Do not reuse a thrust bearing to "absorb" shaft thermal growth — the bearing clamps axially, so growth must be handled on the radial-bearing side of the arrangement.
- The Ca 43/C0a 127 kN ratings and 5.7 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51114; 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 51114?
51114 is a single-direction thrust ball bearing to ISO 104: 70 mm shaft-washer bore, 95 mm outside diameter, 18 mm stack height (2.756 x 3.74 x 0.709 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 43 kN, C0a 127 kN and a 5.7 kN fatigue load limit Pu; the grease limiting speed is 2,400 r/min and the oil rating 3,400 r/min; mass about 356 g.
How is the 51114 designation structured?
511 is the dimension series (light-section 51100 thrust family); 14 encodes the 70 mm bore (bore code x 5). The 95 mm OD and 18 mm height follow the ISO 104 boundary plan for that series.
Can 51114 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 51114?
At the 2,400 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 51114?
The 70/95/18 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 43 kN / C0a 127 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.