6801-2RS Ceramic Bearing Si3N4 ABEC-5 12x21x5 Ball Bearings

This VXB 6801-2RS ball bearing has silicon nitride ceramic ball bearings, ABEC 5 precision, and double seals. It has a 12 mm inside diameter, a 21 mm outside diameter, and a 5 mm depth. This single-row ball bearing has deep groove geometry for applications that require high speeds and support both radial and axial loads. The chrome steel races provide durability and the silicon nitride (Si3N4) ceramic balls provide high hardness, shock tolerance, and resistance to heat and fracturing. A chrome steel cage prevents the balls from coming into contact with each other during use, reducing friction, vibration, and noise. The bearing has C3 radial internal clearance for radial slack between the inner and outer rings that is greater than CN (normal) to compensate for thermal expansion. Rubber seals on both sides of the bearing keep the lubricant in and contaminants out and the bearing is intended for use in general purpose applications. Rolling bearings use rolling elements to maintain the separation between moving parts to reduce rotational friction and support radial and axial loads. These elements can be one of the following types: ball, cylindrical, spherical, barrel, needle, spindle, or tapered. All rolling bearings are open, shielded, or sealed. Sealed bearings are lubricated with oil or grease in the bearing factory, while open and shielded bearings are meant to be lubricated in place, with periodic reapplication of lubrication, based on use. The shield protects the working parts of the bearing from environmental debris that may be introduced and could reduce the ball bearing speed and lifespan. Rolling bearings are used in a range of applications from agricultural machinery to conveying equipment, robotics, dental equipment, elevators, rolling mills, ship rudder shafts, and aggregate crushers, among others.