The main process for making door knobs are - Casting and forging. In the casting process molten metal is poured into a mold. In forging process, under high pressure, heated metal is put into shaped dies. Of these two methods, forging is preferred because they can produce products which are durable, Strong, tough and reliable. Forging process is also both efficient and economical.

Forging

In forging process high temperature is required for softening the metal. This is done by forcing the billets into the furnace having the temperature of 1400°F. After the billets are softened, they are placed in dies to give them definitive shapes. Ones the door knob is given shape they are ejected from the die press. After being ejected they undergo certain process like cooling, trimming, tempering, and cleaning in order to remove heat scale produced during the process.

The second step is the Surface preparation of the door knob, which is achieved by coining, milling, drilling, and tapping processes. After these processes surface of the door knob gets ready for the polishing operation.

Once the surface is polished they are coated using organic and inorganic compound. The popular organic compound used for coatings are: polyurethanes, acrylics, and epoxies. However an organic coating is not so perfect and there are many problems attached to them. Due to this reason, now manufacturers are using inorganic coatings based on inert metals. Inorganic coating is done through electroplating or physical vapor deposition (PVD).