Hign-concerned Chemical : None is_customized : Yes Material : Bearing Steel Model Number : ACB3748H7 Headsets Bearing 37x48x7 mm Brand Name : FUSHI Origin : Mainland China Certification : RoHS,None Tech Brief Bearing seal cross-section At 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 : ACB3748H7 Type : Angular Contact Bearing Inside Diameter : 37 mm Outside Diameter : 48 mm Thickness : 7 mm Inner Chamfer : 45 degree Outer Chamfer : 90 degree Qty: 1 Lot = 1Pc The 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