51180 bearing: complete specifications & equivalents
The 51180 is a ISO 104 radial bearing sized 400 x 480 x 65 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 400 mm |
| Outer diameter D | 480 mm |
| Width B | 65 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 390 kN |
| Basic static load rating C0 | 2010 kN |
| Fatigue load limit Pu | 43.5 kN |
| Limiting speed (mechanical) | 480 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 23300 g |
| Manufacturer designation | NTN 51180 |
| 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 | 15.748 in |
|---|---|
| Outer diameter D | 18.898 in |
| Width B | 2.559 in |
| ISO bore code | 80 |
| Radial section height (D−d)/2 | 40 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) | 40 of 46 |
| Bore above smallest 51100-series size | 390 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 51180 model number is decoded
From the light-section 51100 thrust family, 51180 measures 400 mm through the shaft washer, 480 mm over the outside and 65 mm in assembled height. Reading the code: 511 is the dimension series (light-section 51100 thrust family), and 80 encodes the 400 mm bore (bore code x 5). The washer section here is 40.0 mm of radial height, and the catalogue couples it with Ca 390 kN / C0a 2010 kN. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51180 cannot. 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 mixer and reactor vertical shafts
- bulk-handler stacker/reclaimer thrust pivots
- heavy rotary furnace and kiln thrust points
- vertical hydro and pump-turbine thrust supports
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
- edge loading from a shaft washer mounted off-centre, cutting the contact ellipse short at one side of the track
- 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 400 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 511 light section is the speed-friendly end of the thrust-ball plan — for the same 400 mm bore it gives up load to gain OD, height and limiting-speed headroom.
- The C0a of 2010 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 C0a of 2010 kN is a static rating: sizing continuous working thrust from C0a alone overstates what the raceway survives.
- The Ca 390/C0a 2010 kN ratings and 43.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51180; 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 51180?
51180 is a single-direction thrust ball bearing to ISO 104: 400 mm shaft-washer bore, 480 mm outside diameter, 65 mm stack height (15.748 x 18.898 x 2.559 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 390 kN, C0a 2010 kN and a 43.5 kN fatigue load limit Pu; the grease limiting speed is 480 r/min and the oil rating 690 r/min; mass about 23300 g.
How is the 51180 designation structured?
511 is the dimension series (light-section 51100 thrust family); 80 encodes the 400 mm bore (bore code x 5). The 480 mm OD and 65 mm height follow the ISO 104 boundary plan for that series.
Can 51180 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 51180?
At the 480 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 51180?
The 400/480/65 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 390 kN / C0a 2010 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.