The development of door hardware accessories is closely related to the evolution of the door and the way of opening the door, the reason of the revolution of the door hardware is from consciousness of door function and convenience to use the door. The accurate description of the development history of door hardware requires a lot of work, here we only rational suppose the development procedure of the door hardware which is driven by the demand of mankind. when the use of glass by humans has not yet been universal, door is used for lighting and for the people at a distance or watch the outside world. Door Hardware,Zinc Die Casting Door Handle,Zinc Die Casting Door Knob,Zinc Die Casting Door Hinge NINGBO ZHENHAI BOLANG METAL PRODUCT FACTORY , https://www.aldiecastings.com