Technical Description of a Doorknob
Table of Contents
Introduction
Materials
Manufacturing Process
Knob
Chassis
Rose
Spindle
Thumb turn
Cylinder
Latch bolt
Latch faceplate
Latch assembly
Strike plate
How to Use and Install a Doorknob
Conclusion
References
Introduction
A doorknob is a common and essential piece of hardware that allows people to easily open and close doors while providing a secure way to lock the door. These smooth but sturdy objects with a faint metallistic scent are known to all for their accessibility and simplicity, but few know about the components and functions of a working doorknob. According to “The History Of Door Knobs”, the standard doorknob was invented by Osbourn Dorsey in 1878, which revolutionized modern interior and exterior designs. Doorknobs have existed as long as doors have, but until Dorsey’s invention, most doors had some form of pull handle with a key used to lock the door. Some other ancient doors can be opened by swinging, folding, sliding, or rolling and were typically installed with a lever or a doorknob. They can be dated back to as early as ancient Egypt and Babylon, some 6000 years ago. However, not many people could afford locks and keys, so they relied on latch-string mechanisms to provide security to one’s belongings. Today, we use doorknobs on practically every type of door, with locking mechanisms placed in exterior doors and no locks on interior doors to facilitate easy access inside. There are ten main components to a standard doorknob that work together to create a functional mechanism that can be used to open and close doors.
Materials
Originally, the first doorknobs were made out of wood or metal in the first half of the nineteenth century. However, over time people started creating doorknobs using glass, ceramic, plastic or other different types of metals. The most common material used to create doorknobs till this day is brass because of its durability, strength as well as its resistance to rusting. According to “How doorknob is made”, the average diameter for a doorknob is 2.25 inches in diameter and the most common shape of a doorknob is a spherical or ball-shaped knob which are also considered to be the hardest to turn.
Manufacturing Process
There are many ways to manufacture a doorknob, but the most common method is through forging. Forging is a process where a manufacturer forces heated metal into a distinct shape under extreme pressures. According to “How Products are Made”, a billet (long shaped bar of metal) should be heated up to 1,400° F in a gas-fired furnace so that the metal softens. Next, the heated billet is added to a steel die (precision tool used to shape steel) where it is molded into a distinct form where a press applies high pressure to force the billet into a die cavity till the metal takes the shape of a doorknob. Afterwards, it is cooled, cleaned and tempered and ready to be coated.
Components of a doorknob
The ten basic parts of a typical doorknob are the knob, chassis, rose, spindle, thumb turn, cylinder, latch bolt, latch faceplate, latch assembly, and strike plate. Each of these components has a distinct purpose and has a special function that when combined, form a working doorknob. This is a list of every element that demonstrates and clarifies the function, appearance and location of each part.
Knob
The knob’s purpose is to release the latch and open the door by turning it or pressing down on it. Knobs have a cylinder with a keyhole in the middle on the exterior, and they typically have a thumb turn on the inside. The outside knob is situated at the lock’s very edge. The interior knob is turned to the other side.
Chassis
The knob’s internal component, the chassis, is in charge of guarding against tampering with the locking mechanism. It has a round shape, a little wider external diameter than the borehole on the door, and is composed of steel. It is positioned so that it may completely cover and protect the latch assembly’s borehole.
Rose
The sole purpose of a rose is to conceal the door lock’s chassis and other internal components. It is a decorative cover that is available in a variety of forms. Roses typically have spherical shapes; however, that is not always the case. The rose comes in a variety of styles and has a diameter that is greater than the borehole. Typically, it is constructed of metal and it substantially enhances the doorknob’s design and appearance. It is located in the space between the knob and the chassis.
Spindle
The door knob’s spindle retracts the latch bolt when it is turned. A crucial factor is the spindle’s length because it must match your door’s thickness. A spindle is a steel, square-shaped, elongated rod. The majority of spindles are 9/32 inches wide. Spindles come in a variety of forms, including threaded, drilled, and slotted. After installation, it is hardly noticeable. The spindle passes through the latch assembly and links the outside and interior knobs.
Thumb turn
The thumb turn, also known as the lock button, is what allows a door to be locked from the inside without a key. The majority of privacy doorknobs have this capability. The thumb turn has a small, circular button with a steel construction. It is located at the end of the interior knob, where it is slightly recessed.
Cylinder
The lock cylinder serves as the lock’s body, allowing a key to lock and unlock a door (or turnkey). When locked, it prevents the knob from turning and the bolt from retracting. The cylinder is a crucial component of any door lock arrangement. It has a cylindrical form and a keyway on the external end. The cylinder extends from the center of the exterior knob to the doorknob’s locking mechanism.
Latch bolt
A latch bolt’s (often spring-operated) purpose is to maintain the door’s closed position. The door can be opened by turning the knob, which causes the spindle to retract the bolt. The bolt extends into the door frame’s strike plate hole. A latch bolt looks like a D-shaped piece of metal. It is perpendicular to the plane of the knobs and is situated on the edge of the door.
Latch faceplate
The faceplate fastens the latch to the door while also shielding the latch’s body from damage. It is a metal plate with many different shapes, although it often has a rectangular shape with rounded or right-angled corners. It is located around the latch bolt and is buried into the edge of the door.
Latch assembly
The latch assembly’s function is to directly activate and operate the bolt. The spindle that runs through the assembly is attached to the latch assembly. In essence, it contains the entire latch mechanism. It appears as a rectangular piece of metal hardware with a faceplate and latch bolt on one end. It is situated in the door’s edge bore.
Strike plate
The purpose of a striking plate or door latch plate is to strengthen and secure the mortise on the door jamb into which the bolt extends. Moreover, it directs and secures the bolt, keeping the door shut. It has a rectangular hole in the center of a rectangular metal plate. At the top of a mortise on the door frame. When mounting the striking plate on the jamb, you must use screws that are at least 2½ inches long for increased security.
How to Use and Install a Doorknob
The operation of a doorknob is quite simple. When the knob is turned, it rotates the spindle, which in turn operates the latch assembly. The latch retracts, allowing the door to be opened. When the knob is released, the spring-loaded latch returns to its original position, securing the door in place. According to “How to Install a Doorknob in 7 Steps”, in order to install a doorknob, one must remove the old door knob, latch, and strike plate. Next, set up the new latch and install the latch and latch plate on the wall. Afterwards, install the first and second knobs on opposite sides of the door and tighten their screws thoroughly. Lastly, test the doorknob to make sure the door can open and close and brush off any chips and scratches using a paintbrush.
Conclusion
These ten components are responsible for the structure, function, and mechanics of a working doorknob. Each piece works together to smoothly integrate a working doorknob so that it is accessible and easy for everyone to use. Doorknobs are critical components in architecture and design, an essential part of our lives, providing a simple and efficient mechanism for opening and closing doors. From basic designs to more sophisticated variations, the doorknob has undergone significant changes throughout its history, with each new innovation improving its functionality, security, and durability. Today, doorknobs are an essential part of our lives and can be found in a wide variety of styles, shapes, and sizes, allowing anyone to select the perfect fit for any of their needs.
References
How doorknob is made – material, making, history, used, components, dimensions, composition, structure, steps. (n.d.). http://www.madehow.com/Volume-5/Doorknob.html#:~:text=Doorknobs%20have%20been%20made%20of%20many%20materials%2C%20including,materials%20because%20of%20its%20excellent%20resistance%20to%20rust.
Mora, J. (2022, December 3). 10 Different Parts of a Doorknob and Door Lock [With Diagram] – DailyHomeSafety. DailyHomeSafety. https://dailyhomesafety.com/parts-of-a-door-knob/#rose
Ortiz, P. (2023, January 18). How to Install a Door Knob in 7 Steps (With Pictures). House Grail. https://housegrail.com/how-to-install-door-knob/
The History Of Door Knobs. (n.d.-b). https://www.tbks.co.uk/blog/ask-the-expert/the-history-of-door-knobs/
