Hign-concerned Chemical : None is_customized : Yes Model Number : ACB495H6.5 40.5x49.5x6.5 mm Brand Name : FUSHI Origin : Mainland China Certification : RoHS Tech Brief Bearing seal cross-sectionAt FUSHI we manufacture and use Angular Contact Bearings (ACB) for our headsets. We use only the best manufacturing and quality control methods available. The manufacturing process begins with the rough shape of the bearing races being machined from high quality steel. Both the inside and outside of each race is then precision stone-ground to reach its final shape. Computer controlled grinding equipment is used to grind each race to exact tolerances. The races are then assembled with the balls to create the finished bearing.Caged Bike ball bearing Description :Enable to replace original parts (crankshaft bearing, headsets, hubs). The diameter are measured inside and outside (it's an approximate value in mm). Item : ACB495H6.5 45/45 Type : Angular Contact Bearing Inside Diameter : 40.5 mm Outside Diameter : 49.5 mm Thickness : 6.5 mm Inner Chamfer : 45 degree Outer Chamfer : 45 degree Qty: 1 Lot = 1 PcThe color of the seal is not sure. If you mind it, please contact us before you buy the bearing. All about Headset Bearings:1. How many different types of bearings are used in the modern day headset? Answer: There are at least 6 different kinds of bearings used in the bicycle headset. They include; radial bearings, thrust bearings and angular contact bearings. These three types of bearings all use ball bearings. The second category of bearings is the roller bearings which include the standard roller bearing and the tapered roller bearing. Both of these use cylindrical rollers. 2. There are many different types of bearings. Which one is best for the bicycle headset and why? Answer: Angular contact bearings are the most appropriate bearing for most headset applications. The primary reason is due to the fact that it is very efficient at dealing with the angular force that is exerted upon it. Whereas most deep groove industrial bearings are very efficient at dealing with vertical or horizontal loads, the pressing angle associated with the bicycle headset is much more angular. Most of headset use big diameter axle to increase the strength. As the limited space, the bearing should have a big bore with thin wall of inner ring and outer ring to insert in. ACB has a primary advantage that reinforces axial loads over than deep groove ball bearings. Angular Contact Ball Bearing is very efficient at dealing with both vertical (radial) and horizontal (axial) loads. Its great performances differ from other industrial bearing that only perform well in one direction. In many applications, ACB is used in pair due to its internal construction. It should be installed face to face or back to back in order to support the forces coming from any directions. 3. Are there different types of Angular Contact Bearings? Answer: Yes. In fact, we makes four different types or grades of angular contact bearings. They are: -High End ACB- We manufacturevery high-end angular contact bearings that feature stainless races and ball bearings, or Ceramic balls. While these bearings have a minimal chamfered area, because they press in to the headset cup, they offer superior longevity, durability and perform