what is bearing ?

bearing is a important rotation part. it not only can reduce the friction of roation , but also can play the role of support.  bearing have many kinds of type.  bases on rolling element , its have ball bearing, roller bearing and needle bearings.  bases on using , it have agriculture meachinery  bearing , automotive bearing, industry bearing , windows slide bearing ........ bases on material , it have chrome steel bearing , carbon steel bearing , ceremic bearing , stainless steel bearing , plastic bearing...... different type bearing used for different where,  NAF bearing have almost all type .next article will be introduce one by one.