51200 bearing: complete specifications & equivalents
The 51200 is a ISO 104 radial bearing sized 10 x 26 x 11 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 10 mm |
| Outer diameter D | 26 mm |
| Width B | 11 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Basic dynamic load rating C | 12.7 kN |
| Basic static load rating C0 | 17.1 kN |
| Fatigue load limit Pu | 0.77 kN |
| Limiting speed (mechanical) | 5800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 30 g |
| Manufacturer designation | NTN 51200 |
| 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 | 0.394 in |
|---|---|
| Outer diameter D | 1.024 in |
| Width B | 0.433 in |
| ISO bore code | 00 |
| Radial section height (D−d)/2 | 8 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) | 1 of 39 |
| Bore above smallest 51200-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 51200-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 51200 model number is decoded
51200 is the 10 mm member of NTN's medium-section 51200 thrust family: 26 mm across the washers, 11 mm tall. NTN builds the number from 512 is the dimension series (medium-section 51200 thrust family); the bore code 00 maps to the 10 mm bore by the standard table. At 11 mm of height the stack is compact for the 10 mm bore class, trading section height for the medium-section load level. Against a thrust roller bearing of the same 10 mm bore, this bearing is cheaper, quieter and happier at speed, but carries far less load per mm of section. The shaft washer (bore 10 mm, tight on the shaft) and the housing washer (slightly looser bore) are not interchangeable — check the catalogue bore codes before pressing anything on.
Typical equipment & failure modes
Common applications
- automotive steering-gear and clutch release points
- small crane hook and swivel-joint thrust supports
- valve actuator and gearbox thrust seats
- food-machine vertical auger shafts
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
- 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
- Small thrust washers of 10 mm bore bend if the shaft shoulder is rough — check burrs before seating, and never press on the housing washer to drive the shaft washer home.
- The 512 medium section is the default choice: balanced height and capacity for general vertical-shaft duty at 10 mm bore.
- 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.
- Grease in a horizontal-washer seat stays only if the housing is designed to hold it; open vertical arrangements need an oil bath or a grease-retaining cover.
- Below the minimum axial load the balls skid; the catalogue Ca of 12.7 kN never saves a bearing that is running too lightly loaded at 5,800 r/min.
- The Ca 12.7/C0a 17.1 kN ratings and 0.77 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 51200; 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 51200?
51200 is a single-direction thrust ball bearing to ISO 104: 10 mm shaft-washer bore, 26 mm outside diameter, 11 mm stack height (0.394 x 1.024 x 0.433 in). From NTN Ball and Roller Bearings CAT.No.2203E: axial Ca 12.7 kN, C0a 17.1 kN and a 0.77 kN fatigue load limit Pu; the grease limiting speed is 5,800 r/min and the oil rating 8,300 r/min; mass about 30 g.
How is the 51200 designation structured?
512 is the dimension series (medium-section 51200 thrust family); the bore code 00 maps to the 10 mm bore by the standard table. The 26 mm OD and 11 mm height follow the ISO 104 boundary plan for that series.
Can 51200 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 51200?
At the 5,800 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 51200?
The 10/26/11 mm envelope is ISO 104 interchangeable, but washer bore codes, raceway osculation and ratings are maker-specific. Re-verify Ca 12.7 kN / C0a 17.1 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.