Explaining Essential Door Knob Parts

Understanding the parts of a door knob can help if you need to troubleshoot a broken knob or if you want to make an informed purchase.

This article will break down the essential door knob parts, explaining how each one works within the mechanism.

Parts of a Door Knob

• Knob or Lever
• Rosette/Backplate
• Spindle
• Latch or Deadbolt
• Deadlatch/Deadlocking plunger
• Strike plate
• Screws
• Keyhole
• Thumb Turn

Definitions for Door Knob Parts

Standard door knobs have eight main components. By understanding the names of these parts, you can better maintain your door’s hardware.

Knob/Lever

Most door knobs have two knobs or handles, one on either side. They are both decorative and practical, with knobs typically having a spherical shape and levers extending off to the side of the door.

Interior doors may or may not have a lock. Privacy door knobs have a simple locking mechanism on one side. Dummy door knobs have no lock.

For exterior doors, the outside knob has more extensive locking mechanisms. The most popular locking system for standard exterior doors is the pin tumbler cylinder.

The pin cylinder includes a cylinder with pins. Manufacturers create a key to correspond with the pins. When you insert the key into the cylinder, the pins move to the correct position and open the lock. Pin cylinders come in single and double rows.

Single row cylinders are common for most standard door knobs. Look for a double row pin cylinder for high security needs.

Door knobs are made of various materials such as brass, pewter, glass, porcelain, stainless steel, chrome, nickel, wood, and iron.

A rosette or backplate covers the hole in the door where the spindle connects the door knob. They enhance the appearance of the door by concealing the opening and the knob spindle. Additionally, they complement the decorative design of the door knob.

Rosettes are typically round or oval, while backplates are usually square or rectangular.

Interior rosettes/backplates feature set screws that can be removed to take off the rosette and examine the door knob components. Exterior door knobs, on the other hand, do not have disassemblable parts for safety reasons.

The spindle is a rod that extends into the door hole and connects the knob to the latch or deadbolt mechanisms. By turning the knob, the spindle activates the spring bolt in the latch or deadbolt and opens it.

A spindle is a metal rod shaped as a square, round, or splined depending on the lock or latch type. Square spindles are commonly found in standard door knobs, while splined spindles are used in high-security door knobs due to their raised ridges making them harder to remove.

Latches and deadbolts are door handle parts used for locking doors. When the knob or lever is turned, it activates the latch. The latch mechanism has a spring-loaded bar that extends from the door’s exterior edge into a hole in the door frame.

Turning the knob retracts the spring-loaded bar, allowing the door to be opened. Releasing the knob allows the spring mechanism to push the latch back out.

You can activate a deadbolt with a key or a thumb turn. Deadbolts are a valuable security measure because they cannot be easily picked or bumped open. Experts consider deadbolts more secure than door knobs.

Interior doors have only a latch component, while exterior door knob systems include both latches and deadbolts for enhanced security.

A deadlatch or deadlocking plunger is an additional security mechanism for exterior door knobs. This small bolt sits on top of the knob bolt that extends into the door frame. Deadlatches are more secure because they automatically lock when you close the door.

They require a key or a thumb turn to open.

The strike plate is another important element in door security.

A strike plate is a thin metal plate attached to the door frame to reinforce the hole for the knob bolt. It makes it harder for intruders to force open the door and protects the door molding from wear. Additionally, it guides the bolt to the optimal position in the door frame.

While seemingly inconsequential, the strike plate is vital for a properly functioning door. Improper installation can prevent the door from closing properly, compromising the lock and decreasing home security.

Now, let’s talk about setting screws.

Setting screws hold knobs, levers, and spindles in place. Secure the knob tightly against the door so that turning the knob propels the bolt instead of the knob itself. Setting screws are located on the interior side of the door for security.

Tighten them as needed with a small screwdriver.

A keyhole is a part of a door knob that can be found on some doors. All exterior doors have a keyhole on either the knob or a mortice lock section.

The keyhole consists of two elements: the keyway and the tumbler mechanism. The keyway is the opening where the key is inserted to open the door. When a key is inserted and turned, the tumbler mechanism inside the knob is activated.

There are different types of tumbler mechanisms, including pin, wafer, lever, and disc tumblers. The pin tumbler is the most common type found in standard door knobs.

A thumb turn is a mechanism found in some door knobs that allows you to lock the door by turning a bolt, without using a key. It is connected to the door knob through the latch mechanism. Rotating the thumb turn shifts the position of the bolt by turning the spindle.

For safety reasons, thumb turn mechanisms are only present on the interior side of the door knob.