Door Lock Parts: How to Identify and Replace

Three lock cylinders isolated on a white background.

Don’t risk the security of your home by keeping non-functioning locks for the sake of saving money. There are many door lock parts that you can actually repair and replace on your own, without having to call a locksmith.


A latch is the portion of a door lock that extends into the door frame through the strike plate. Often, latches may be sticky, broken, or ineffective. When changing your latch, you may want to consider a flexible latch for a deadbolt or a positive locking latch for added security since standard latches can be forced open easily.

You cannot usually buy latches individually at a standard home improvement store, but you can find them online or at a specialty store such as a locksmith’s store. If you want to replace a latch, bring the old one with you, or make sure you know the model number and style of the old latch.

Strike Plates

person working on a door lock

The strike plate is the part of the lock that attaches to the door frame. The latch goes through the strike plate to form a secure lock or positive closure to the door.

Strike plates come in a variety of shapes and sizes. The opening on these plates may be rounded, squared, or flat on one side and rounded on the other, depending on the shape of the latch that goes into the strike plate. The exterior shape of the strike plate varies according to the decorative features of the door lock, but this is less important to the function of the lock than the interior shape.

The strike plate is the easiest portion of the lock to change, since it requires only two screws to mount it to the door frame. Strike plates are similar to latches in that they are generally not sold separately, but rather as parts of a lockset at big box stores. However, specialty hardware stores and online retailers will have them available separately. Make sure that the style of your strike plate will match up with your latch before purchasing.


The lock cylinder is the meat of the door lock. The cylinder is the part that contains the “code” for the key and determines whether the door locks and unlocks.

If you need a new lock because you lost the key to the door, you may opt for re-keying the cylinder rather than replacing it. If a cylinder is sticking, has a key broken off in it, or is damaged, then you may need to replace the cylinder entirely rather than simply re-keying.

To re-key a cylinder, you will need to purchase a brand-specific re-keying kit. They are available for about $8, and they will re-key six locks each. If you have only a single door that needs to be re-keyed, calling a locksmith may be a good choice. However, if you have multiple doors, then the do-it-yourself option is a good one.

If you decide on cylinder replacement, then visit a specialty lock store, do an internet search, or contact the manufacturer directly. You are also more likely to have success replacing the cylinder on an expensive lock set than on a cheaper one.