51336 bearing: complete specifications & equivalents
The 51336 is a ISO 104 radial bearing sized 180 x 300 x 95 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 180 mm |
| Outer diameter D | 300 mm |
| Width B | 95 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 490 kN |
| Basic static load rating C0 | 1700 kN |
| Fatigue load limit Pu | 49.5 kN |
| Limiting speed (mechanical) | 540 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 27500 g |
| Manufacturer designation | NTN 51336 |
| 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 | 7.087 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 3.74 in |
| ISO bore code | 36 |
| Radial section height (D−d)/2 | 60 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) | 23 of 25 |
| Bore above smallest 51300-series size | 155 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51336-M | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 180×300×95 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 51336 model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, 51336 appears as a heavy-section 51300 thrust family bearing with a 180 mm shaft washer, a 300 mm housing diameter and 95 mm of stack height. The designation is 513 is the dimension series (heavy-section 51300 thrust family) plus 36 encodes the 180 mm bore (bore code x 5). Catalogue mass is about 27500 g for the full washer-and-cage stack. Where misalignment between shaft and housing seats is expected, the spherical-seat washer executions (listed separately in the catalogue) absorb what the flat-seat 51336 cannot. Keep the support faces square: a housing face out of perpendicular by a few hundredths over the 300 mm OD already tilts the raceway and concentrates the 1700 kN static capacity on a few balls.
Typical equipment & failure modes
Common applications
- heavy press and mill screwdown thrust seats
- crane slew-ring auxiliary thrust positions
- large mixer and reactor vertical shafts
- bulk-handler stacker/reclaimer thrust pivots
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
- cage breakage after repeated shock reversal banged the ball set against the pocket bridges
- contamination pitting from particles settling on the horizontal housing washer — the classic failure of vertical-shaft grease-lubricated seats
Selection pitfalls — read before you substitute
- For a 180 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 513 heavy section buys capacity with a larger 300 mm OD and taller stack — check the housing space before upgrading a 512 position to this series.
- The 540 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.
- The 540 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.
- The 540 r/min speed figure assumes the catalogue lubrication state; at high speed the limiting factor is often the minimum load, not the rating table.
- The Ca 490/C0a 1700 kN ratings and 49.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51336; 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 51336?
51336 is a single-direction thrust ball bearing to ISO 104: 180 mm shaft-washer bore, 300 mm outside diameter, 95 mm stack height (7.087 x 11.811 x 3.74 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 490 kN, C0a 1700 kN and a 49.5 kN fatigue load limit Pu; the grease limiting speed is 540 r/min and the oil rating 780 r/min; mass about 27500 g.
How is the 51336 designation structured?
513 is the dimension series (heavy-section 51300 thrust family); 36 encodes the 180 mm bore (bore code x 5). The 300 mm OD and 95 mm height follow the ISO 104 boundary plan for that series.
Can 51336 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 51336?
At the 540 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 51336?
The 180/300/95 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 490 kN / C0a 1700 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.