VXB 608 Full Ceramic Skate Bearing White Ceramic ZrO2 Rings with Si3N4 Black Balls 8x22x7 Ball Bearings VXB Brand Description This 608 ball bearing has races made of zirconium oxide, balls made of silicon nitride ceramic, and a cage made of PTFE. It has an 8 mm inside diameter, a 22 mm outside diameter, and a 7 mm depth. The bearing has deep groove geometry for supporting both radial and axial loads and high speeds. The races are made of zirconium oxide ceramic for durability and resistance to corrosion and high temperatures. The bearing is open on both sides for lubricating in place. The ball is made of silicon nitride ceramic for resistance to shock, corrosion, and high temperatures. A one-piece polytetrafluoroethylene (PTFE) cage spaces the balls for even load distribution and prevents contact to reduce friction, vibration, and noise. This deep groove ball bearing is used in applications such as skateboards and rollerblades, among others.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. Features: Item: 608 skate bearings Type: Full Ceramic Bearing Size: 8mm x 22mm x 7mm Dimensions: 8*22*7 mm/Metric ID (inner diameter)/Bore=8mm Product Details: Brand: VXB Material: ZrO2 White Ceramic Rings with Si3N4 Black Ceramic Balls Bearing Number: 608 Item Thickness: 7 Millimeters Bearing Type: Ball Bearing Is Discontinued By Manufacturer ‏ : ‎ No Package Dimensions ‏ : ‎ 2.87 x 2.64 x 0.31 inches; 0.39 Ounces Item model number ‏ : ‎ Kit7825 Date First Available ‏ : ‎ May 27, 2009 Manufacturer ‏ : ‎ VXB Best Sellers Rank: #232,874 in Industrial & Scientific (See Top 100 in Industrial & Scientific) #2,000 in Deep-Groove Ball Bearings #2,000 in Deep-Groove Ball Bearings Customer Reviews: 3.7 3.7 out of 5 stars 114 ratings