6921 Open Thin-Section Deep Groove Ball Bearing for Gearboxes & Oil-Lubricated Systems | 105×145×20 mm

The 6910-ZZ is a single-row, thin-section deep groove ball bearing from the ISO 6900 series, fitted with double non-contact pressed-steel shields for light contamination protection at minimal drag penalty. Measuring 50 mm bore, 72 mm outer diameter, and 12 mm width, it belongs to the same slim-ring family as other 6900-series bearings but targets applications where the priority is speed capability and low running torque rather than maximum contamination exclusion. With a grease limiting speed of 9,000 r/min and an oil limiting speed of 11,000 r/min, the 6910-ZZ runs meaningfully faster than its rubber-sealed 6910-2RS counterpart — making it the preferred shielded configuration for precision motor spindles, encoder drives, servo actuators, and optical equipment rotating at sustained higher speeds within a compact 50 mm bore housing.

The 6910-2RS is a single-row, thin-section deep groove ball bearing from the ISO 6900 series, sealed on both faces with contact rubber lips for active exclusion of contaminants and reliable long-term grease retention. Sharing the same compact 50 × 72 × 12 mm envelope as the shielded 6910-ZZ, the 2RS variant makes a deliberate trade: it accepts a lower speed ceiling in exchange for a meaningful improvement in contamination exclusion — a worthwhile exchange in any precision application where the operating environment cannot be guaranteed clean. Factory pre-greased and permanently sealed, it is suited for industrial robots, outdoor automation equipment, laser systems, optical instruments, and stepping motor assemblies where fine dust, humidity, or occasional liquid exposure would otherwise shorten bearing life.

The 6907-ZZ is a single-row, thin-section deep groove ball bearing from the ISO 6900 series, shielded on both faces with pressed steel plates fixed to the outer ring. Unlike contact rubber seals, the ZZ shields maintain a controlled non-contact clearance with the inner ring — allowing meaningfully higher operating speeds while still providing practical defence against coarse particle ingress and grease escape. This deliberate configuration makes the 6907-ZZ the preferred choice when shaft speed is the governing constraint and the operating environment, while not clinically clean, is free of active liquid contamination. Factory pre-greased and ready to fit, it serves electric motors, high-speed spindles, optical instruments, stepping motor assemblies, and compact gearboxes where rotational efficiency and dimensional economy matter equally.

The 6907-2RS is a single-row, thin-section deep groove ball bearing from the ISO 6900 series, fitted with contact rubber lip seals on both faces. The seals bond to the outer ring and bear physically against a machined shoulder on the inner ring, forming a positive barrier that actively keeps fine dust, airborne particles, moisture, and light contamination away from the ball complement and grease fill. On a 35 mm shaft, the 6907-2RS delivers the 6900 series' compact 55 mm outer diameter alongside maintenance-free sealed operation — a pairing that makes it the bearing of choice wherever space is fixed, the environment is less than controlled, and re-lubrication access is impractical or simply not planned.

The 697-2RS is a single-row miniature deep groove ball bearing from the 600 series, sealed on both faces with contact rubber lip seals that engage the inner ring shoulder directly. At just 7 mm bore and 17 mm outer diameter, it occupies one of the smallest envelopes in the standard metric ball bearing catalogue while still delivering the contamination exclusion and grease retention that sealed construction provides. This combination — sub-20 mm outer diameter, contact rubber seals, and factory pre-fill — makes the 697-2RS the default choice for compact precision assemblies that run in dusty, humid, or mist-exposed surroundings where open or shielded miniature bearings would require additional housing protection to achieve comparable service life.

Designed specifically for space-constrained, large-shaft assemblies requiring high radial rigidity and minimized weight, the 6921-ZZ is a premium thin-section deep groove ball bearing. Outfitted with dual non-contact metallic shields (ZZ), it delivers exceptional defense against coarse dust and factory debris while ensuring reliable containment of the factory-applied lubrication. Because the metal shields avoid contact friction with the inner ring, the 6921-ZZ maintains minimal running torque and ultra-smooth rotation. This makes it an essential mechanical component for large-bore, weight-sensitive 105mm applications, including industrial robotic joints, heavy-duty rotary tables, and complex automated equipment.

Developed to support reliable radial and multi-directional axial loads within tight radial profiles, the 6921-2RS is a premium thin-section deep groove ball bearing equipped with dual synthetic rubber seals. Outfitted with heavy-duty contact seals (2RS), it provides a highly resilient barrier against fine dust, moisture, and particulate contaminants while preventing internal grease migration. Because these reinforced rubber lips maintain direct contact with the inner ring recess, the 6921-2RS ensures structural protection and lubrication retention in harsh environments. This makes it an invaluable mechanical component for large-bore, weight-sensitive 105mm shaft applications, including industrial robotic joints, heavy manufacturing automation, and rotating platforms.

Engineered for internal mechanical assemblies where external sealing is provided by the housing, the 6921 Open is a high-performance thin-section radial ball bearing. Completely unshielded and unsealed, this open-type configuration allows for unrestricted flow of fluid lubricants directly into the rolling elements. Because there are no physical barriers or rubbing seals, the 6921 Open achieves absolute zero shield-induced friction, ensuring optimal thermal dissipation and maximum rotational efficiency. It is the ideal component for heavy-duty 105mm shaft applications enclosed in oil bath environments, such as industrial transmissions, large centrifugal pumps, and enclosed machine tool spindles.