Ceramic bearings are being seen in bicycles and different hobby equipment, such as for example fishing reels, slot cars, and roller blade wheels. Ceramic bearings can be found in many sizes of bike cartridge bearings. The cartridge bearings usually use steel interior and external races, with ceramic bearings between. Ceramic bearings can even be acquired as loose ball bearings .
The ceramic bearing has found uses in professional applications where there is great speed, high load, and, consequently, temperature. Bicycle riding just does not lead to high load, quickness or temperature. A bike going at 80 kilometers per hour (about 50 mph), could have hubs that rotate about 11 revolutions per second. An engine crank shaft, however, risk turning at over 100 revolutions per second.
The caliber of bearing can be identified by various ratings, including the rating of ball roundness. A top quality metal ball bearing is consider grade 25. The grade quantity refers to the tolerance per millionth of an in .. A grade 25 is exact to 25/1,000,000 of an inches. Less expensive ball bearings could be quality 300, which are a lesser amount of round, at 300/1,000,000 of an inches. Ceramic bearings may be grade 5, which is a rounder ball bearing. The importance of roundness, however, should not 
be overrated, as the bearing areas the balls operate on happen to be unlikely to always be as accurate as the grade of the ball bearing. The ball bearing is typically not the “weak hyperlink” in the system.
Another facet of the bearing is the property of the materials. There is a rating for hardness known as the Rockwell level. Steel uses what’s referred to as the Rockwell C scale, and ball bearings are of course hard. This hardness allows them to rotate and not dress in, at least for some time. The bearings floors of the hub cone and cup routinely have a Rockwell C score of 55 to 60. A steel ball bearing is likely to be over a Rockwell C of 60. A ceramic ball bearings can be a Rockwell C of 75, much harder compared to the steel races. This should provide good wear features for the whole bearing system, not simply the ball bearing itself.
The surface finish of a bearing is also important. Ceramic bearings are not necessarily smoother than steel balls. In the image below, a Grade 25 steel bearing is magnified 200 moments . Grind marks are apparent. In the next picture, a ceramic bearing as well show grind marks .
The ceramic material found in a ball is made of a grain structure, similar to a steel ball bearing . A significant property of any materials is “stiffness.” This is a way of measuring how it deflects under stress or load, and the score of this property is named the “Modulus of Elasticity.” A steel bearing will be maybe 30,000,000 pounds per square inch. Ceramic bearings made from silicon nitride can have a Modulus of Elasticity of 47,000,000 pounds per square in .. This extra stiffness means the balls will deflect a lesser amount of under load and this will transfer strength better, proving a (tiny) savings. As the ceramic ball is approximately one-half the fat of a steel ball the same size, it’s the stiffness that’s important within their performance.
It terms of service, there is absolutely no exceptional procedure or process. Bearing could be cleaned and lubricated as regular. Loose ball bearings will be installed and adjusted much like metal balls. Install bearings and completely cover with grease.
With cartridge bearings, it is possible lift the seal and check the grease. Remove the spindle or axle initial. For many cartridge bottom bracket bearings, it is necessary to carefully remove the a plastic shield over the bearing. Use a seal pick to lift up the rubber seal from the inner edge . Wipe the bearing clean with a rag and then add grease. Press seal into place.
Build a Basic but Fun Steel Ball Bearings china Magnetic Gauss Gun a.k.a. Magnetic Rail Gun
The 3 items you need are Cylinder Neodymium Magnets, Metal Balls and PVC Conduit for the road of the gun.