This product series features the quintessential Imperial 6.35mm (0.25-inch) inner diameter specification—widely regarded as the "gold standard" for miniature mechanical power transmission systems. Crafted entirely from high-grade bearing steel, the series boasts exceptional mechanical strength and hardness; furthermore, through a precision heat treatment process, these bearings demonstrate superior resistance to deformation during prolonged operation under load. Their deep-groove ball structure is engineered not only to efficiently support radial loads but also to accommodate bidirectional axial loads to a significant degree.
Bearing Features
Based on technical specifications, this series addresses diverse operational requirements of varying intensity through flexible adjustments in outer diameter and thickness. This tiered performance design ensures the series maintains a pivotal role in applications ranging from small electric tools and precision transmission mechanisms to industrial control sensors. Moreover, the design of these bearings places particular emphasis on dust protection and sealing capabilities, effectively preventing external contaminants from entering the raceways and thereby reducing maintenance frequency.
Technical Specifications
| Bearing Reference | Boundary Diameters | Basic Dynamic | Basic Static | Limiting Speeds | ||||||||||||||||||
| Flange | Open | Shield | d inch |
d mm |
D inch |
D mm |
Df inch |
Df mm |
B inch |
B mm |
Bf inch |
Bf mm |
B1 inch |
B1 mm |
Bf1 inch |
Bf1 mm |
rsmin inch |
rsmin mm |
Cr kN |
Cor kN |
Grease | Oil |
| F | R168 | ZZ | 0.25 | 6.35 | 0.375 | 9.525 | 0.422 | 10.719 | 0.125 | 3.175 | 0.023 | 0.584 | 0.125 | 3.175 | 0.036 | 0.914 | 0.0039 | 0.1 | 0.372 | 0.176 | 4.2 | 4.7 |
| F | R188 | ZZ | 0.25 | 6.35 | 0.5 | 12.7 | 0.547 | 13.894 | 0.125 | 3.175 | 0.023 | 0.584 | 0.1875 | 4.762 | 0.045 | 1.143 | 0.0059 | 0.15 | 1.08 | 0.441 | 3.5 | 3.9 |
| F | R4 | ZZ | 0.25 | 6.35 | 0.625 | 15.875 | 0.69 | 17.526 | 0.196 | 4.978 | 0.042 | 1.067 | 0.196 | 4.978 | 0.042 | 1.067 | 0.0118 | 0.3 | 1.48 | 0.617 | 3 | 3.3 |
| - | R4A | ZZ | 0.25 | 6.35 | 0.75 | 19.05 | - | - | 0.2188 | 5.556 | - | - | 0.2812 | 7.144 | - | - | 0.0157 | 0.4 | 2.33 | 0.892 | 2.6 | 2.9 |

A flange bearing is a housed bearing assembly in which the outer housing carries a machined flange plate drilled with mounting holes. The flange plate allows the unit to be bolted directly onto a mac...
View MoreMost procurement teams comparing stainless steel bearings hold a material comparison sheet. 440C versus 316. Hardness versus corrosion resistance. Magnetic versus non-magnetic. None of that informati...
View MoreBearing Steel: The Metallurgical Foundation Behind Every Rolling Contact Every rotating assembly in modern machinery depends on a handful of highly engineered contact points. A pump running at 3,600 ...
View MoreAngular contact ball bearings are essential for handling combined loads because their inner and outer raceways are offset along the bearing axis. This built-in contact angle creates a direct, uninter...
View MoreIn a special production environment, many stainless steel bearings are equipped with corresponding sealing devices. On the one hand, it keeps the grease (oil) inside the stainless steel bearing from b...
View MoreUnder normal circumstances, stainless steel bearings will produce a certain amount of noise during machine operation. However, if the vibration level of stainless steel bearings increases significantl...
View MoreStainless steel bearings offer numerous advantages not only due to stringent manufacturing processes and precision requirements, but also because of the superior quality of the material itself. When s...
View More