Lock Anatomy: Learn about lock parts and how to describe your issue

When it is time to call a locksmith about an issue with your lock hardware, knowing the terminology is a great way to get the best information. The better we understand the problem before we arrive, the better prepared we can be with the right hardware and an accurate advance quote. Today we will take a look at the basic anatomy of the parts involved with your lock, door, and door hardware to give you the tools you need to describe your issue with confidence.

Lock Parts: Anatomy

Door:

The face bore is the hole in which all the components of your lock come together. The backset is the distance between the center point of the face bore and the edge of your door. This is a measurement you will need to know when ordering new hardware. The two standard backsets are 2 3/8" and 2 3/4". The edge bore is the hole where the latch is installed. The latch plate mortise is a recess in the edge that enables the latch to sit flush once installed.

Latch:

The latch is the tongue portion of your lock that sits within the door jamb and retracts when the knob is turned to allow entry. When your door is locked, it is locked by disabling the retraction of the latch. The face plate is the area around the latch where you mount the latch assembly to the edge of the door. The strike plate is a piece that is mounted on the door jamb to securely keep the latch in place when the knob is in its default state. We have also labeled the backset here, to help illustrate why that measurement is so important to fit the lock to your door.

Knob:

The knob is the area of the device you turn to retract the latch and open the door. This is the portion of the lock that is most open to design options, including finish and shape. Levers are also available in place of a knob. The rosette is the piece closest to the door that blocks access to the mechanism within the face bore. The cylinder contains the components that allow your key to work the lock while disallowing other keys of the same type that are cut differently from yours. When a

key is inserted into the keyhole, the cuts in

your key align these components and allow

the cylinder to turn, unlocking your door. The spindle is a collection of hardware that allows all these disparate parts of your lock to connect and function appropriately.

Hinge:

A hinge consists of 3 main parts. There are two leaves: one leaf attaches the hinge to the door frame and the other attaches the hinge to the door. Each leaf has a series of knuckles that align to create a cylindrical opening through which the pin is inserted. Collectively, this is the device that allows the door to swing open and closed freely at a fixed distance from the frame. The 3 measurements of a hinge are:

1. Length: total height of the leaves

2. Leaf width: width of an individual leaf

3. Hinge width: total width of the hinge from one leaf edge to the other