STD 627 RS Skate Rated "Ceramic" Bearings 7mm Set of 16

Set of 16 STD Skates 627 RS skate rated "CERAMIC" bearings are specialized, high-performance precision bearings engineered specifically for artistic figure roller skating and quad skates utilizing an 7mm axle diameter. They are sold as a 16-unit set to fully outfit a complete pair of quad roller skates. Unlike standard industrial 627 bearings, these are calibrated via a specific mechanical adjustment to handle the exact physical forces experienced during skating.
 
Radial Clearance: This takes into account the space between the balls and the raceways of the rings. In the Skate Rate calibration, an intentional clearance is left. This prevents the bearing from seizing up when a little dirt gets inside or when heat expands the metals during intense training.
High Lateral Load Capacity: Quad skating, especially figure and artistic skating, applies massive sideways pressure. The deeper raceway grooves prevent the balls from slipping off their tracks or "biting" into the metal casing when taking sharp edges or landing jumps. 
Intentional Radial Clearance: A calculated gap is left between the balls and the inner rings. This prevents the bearings from seizing up when the metal expands due to intense training friction or if microscopic debris breaches the seal. 
Groove Depth Calibration: A bearing calibrated for skating has deeper ball grooves to increase structural stability under impacts (jumps, spins).
Enclosure Type: "RS" indicates a rubber seal on the sides to protect the internal components from dust, dirt, and moisture.
Size: 627 standard size (7mm inner diameter, 22mm outer diameter, 7mm width). Specifically tailored for 7mm skate axles commonly found on professional artistic quad skate plates.
Design Type: Radial deep-groove bearing customized for high-performance skating forces.
Materials: Steel inner/outer rings with specialized ceramic elements and a lightweight cage. 
Skate Rated Calibration: Built with specific radial clearances to prevent seizing under heat expansion or debris accumulation during intense training.
Reduced Friction: Ceramic materials lower rotational resistance for a longer, smoother roll.

STD Bearings Ratings Summary
Beginner: Balanced calibration between speed and impact resistance = STANDARD
Precision: Calibration with finer tolerances for maximum inertia (rolls longer without pushing off) = DEEP GROOVE
Competition: Calibration focused on minimal friction, with mirror-polished balls and ceramic coating = CERAMIC