Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When your rotating assembly demands reliable axial load handling in wet, corrosive, or high-cycle environments, standard carbon steel bearings fall short fast. Engineers, machinists, and serious DIYers working on pumps, marine hardware, rotary tables, and precision jigs need a thrust bearing that holds its geometry and resists surface degradation over time. These 440 stainless steel thrust ball bearings are built for exactly that application.
Each bearing is a three-part assembly — shaft washer, housing washer, and ball-and-cage assembly — machined from 440-grade stainless steel. The S511 series covers inner diameters from 10 mm (0.39 in) to 130 mm (5.12 in) with outer diameters ranging from 24 mm (0.94 in) to 170 mm (6.69 in) and thickness from 9 mm (0.35 in) to 30 mm (1.18 in). The S512 series offers a heavier-duty profile with increased thickness for the same bore range, with thickness values from 11 mm (0.43 in) to 35 mm (1.38 in).
Typical use cases include axial load management in vertical shaft pump assemblies, thrust positioning in CNC rotary axis builds, and corrosion-resistant bearing replacement in marine deck hardware and food-processing equipment where stainless is a specification requirement.
| Series | S511 (light duty) / S512 (medium duty) |
|---|---|
| Material | 440 Stainless Steel |
| Bearing Type | Thrust Ball Bearing, Three-Part |
| Inner Diameter (ID) Range | 10 mm – 130 mm (0.39 in – 5.12 in) |
| Outer Diameter (OD) Range | 24 mm – 170 mm (0.94 in – 6.69 in) |
| Thickness Range | 9 mm – 35 mm (0.35 in – 1.38 in) — varies by variant |
| Load Direction | Axial (Thrust) Only |
| Cage Material | See variant options |
| Lubrication | See variant options |
| Dynamic Load Rating (C) | See variant options |
| Static Load Rating (C0) | See variant options |
| Max Operating Speed | See variant options |
| Operating Temperature | Contact us to confirm |
The S511 series has a thinner profile and is suited for light axial loads where space is limited. The S512 series uses a thicker cross-section for the same bore diameter, providing a larger ball complement and higher load capacity. If your application involves significant thrust forces or shock loading, the S512 is the better choice. Check the variant name — S511xx vs S512xx — and match the thickness to your housing depth.
These bearings are designed for axial (thrust) load applications including vertical shaft pumps, rotary tables, and similar equipment. The 440 stainless construction provides adequate strength for moderate-duty industrial use. For heavy-duty or high-speed pump applications, verify the dynamic load rating (C) against your calculated bearing load before selecting a size.
440 stainless steel offers good corrosion resistance in freshwater and mildly corrosive environments. In continuous saltwater immersion or highly chlorinated environments, 316 stainless would be more appropriate. For intermittent marine exposure — such as deck hardware or bilge pump shafts — 440 stainless performs well when kept clean and lightly lubricated.
No. Thrust ball bearings are designed exclusively for axial (thrust) loads applied parallel to the shaft axis. Applying radial loads to a thrust bearing will cause rapid wear, ball skidding, and premature failure. If your application involves combined radial and axial loads, use an angular contact or deep groove ball bearing instead.
Measure three dimensions with calipers: (1) Inner Diameter (ID) — the bore that fits over the shaft; (2) Outer Diameter (OD) — the overall outside diameter; (3) Thickness (T) — the total height of the assembled bearing. Match these three values to the variant name format shown in the listing: ID × OD × Thickness in millimeters. For example, S51104 (20×35×10) means ID=20mm, OD=35mm, Thickness=10mm.
Lubrication state varies by variant — please contact us to confirm for your specific size. As a general practice for thrust ball bearings, applying a light coat of grease (NLGI #2) or oil to the raceways before installation is recommended, particularly in applications with moderate speeds or where re-lubrication access is limited.
The shaft washer (the washer with the smaller bore) seats against the rotating shaft shoulder. The housing washer (larger bore) seats against the stationary housing. Installing them reversed will cause the bearing to run incorrectly and wear prematurely. The ball-and-cage assembly sits between the two washers. Ensure both mating surfaces are flat, clean, and free of burrs before assembly.
