In the United States, there are two common backsets for residential door locks: 2 3/8 inches and 2 3/4 inches. Pack your locks with a 2-3/8-inch or 2-3/4-inch latch, depending on which backset you specify.
You can work out the size of the lock by measuring the distance from the edge of the door to the centre of the door handle or knob. This measurement will give you the approximate size of the backset which will allow you to identify which size lock or latch you have.
The case depth is often simply stated as the 'lock size'. There are many different case depths but the most common sizes are 64mm and 76mm.
The two most common are 5-1/2” and 6” from the centers of the two holes. There are other combinations of spacing which are used on specialty locks, however. When adding a deadbolt lock, your best choice would be one of standard measurement.
Most types of locks for doors will work on both types of door handings. These locks are labeled as "reversible handing" or "universal handing" and can be installed on either side of the door.
Some models disengage the lock when you manipulate the inside lever, offering a simpler means of exit. Door levers are left-handed, right-handed or universal. To determine what you need, look at the door from outside the house or room. If the hinges are on the left, look for a left-handed or universal lever.
When you move into a new home, you should change the locks on your house. You have no idea how many copies of the house keys are floating around out there from the previous homeowners, so changing the locks will keep your new house more secure. Tom recommends changing the locks whenever a new home is purchased.
Even though there is a standard size for deadbolts, you might need smaller or larger sizes depending on the size and thickness of your door. Different brands have deadbolt sizes as small as 2 inches and as big as 5 inches.
Deadbolts are available in different sizes based on the manufacturer. However, common deadbolts are 2 ⅛ inches in size and require a 1-inch gap in the door frame for the bolt, with a distance of 5 ½” to 6” between the two locks.
Are Door Knob Sizes Universal? While door knobs commonly come in standard measurements, they aren't universal. Standard-sized door knobs have a better fit with most modern doors because they follow this standard. On older doors, they most likely won't fit because the doors have smaller measurements.
There are two sizes of mortice locks: 21/2” and 3”. If you are installing a mortice lock to a door with a narrow frame, or any door for that matter, it's very important to know what size lock you need. The size of the mortice lock refers to how far the keyhole will be from the edge of the door.
The standard sized bore hole is 2 1/8" in diameter. Through the edge of the door there is a 1" cross bore that extends from the edge of the door through the bore hole. This cross bore is where the latch is installed.
Are mortise door locks universal? Yes, a mortise lock set and mortise door lock is universal and can easily be used to replace most other lock sets, especially on an older door.
Deadlocks vs sashlocks
A deadlock is a lock that is permanently shut once you've locked it, until you unlock it. It doesn't latch shut, nor does it open without a key (unless there is a thumbturn cylinder on the inside). A sashlock is all of the above things, plus there's a latch and a pair of handles.
Standard Door Prep for Door Knobs & Levers:
The standard sized bore hole is 2 1/8" in diameter. Through the edge of the door there is a 1" cross bore that extends from the edge of the door through the bore hole. (This cross bore is where the latch is installed).
There are plenty of other door locks, and many fall within the seven categories of knob locks, deadbolt locks, cam locks, padlocks, mortise locks, smart locks and keypad locks. For example, lever handle door locks are used for inner doors and work much like knob locks.
A deadbolt lock will secure your door from would-be thieves. Every exterior door should have at least two locks to deter them.
It may be a bit longer or shorter, and the end may look slightly different depending on the brand of lock. The depth of the cylinder is determined by the depth of the lever, and the end is determined by how the cylinder engages the locking mechanism of the lever.
The deadbolt lock set has a template that you can use to measure. Most standard deadbolts require a 2-inch hole saw for the lock bodies and a 1-inch spade bit for the sliding bolt assembly, so be sure to use the correct size drill bits.
Most deadbolt locksets come with keys when purchased new. If not, you can rekey these locks to fit the current keys you already have. But keep in mind that rekeying cannot be performed on all types of door locks. For older locks, check their condition to see if they can be rekeyed or if they should be replaced.
Replacing door locks is a relatively simple DIY project. If you know your way around a basic screwdriver, you should be able to tackle it in under an hour. Full installation instructions come with the new locks and customer support hotlines are often available to answer any questions.
Rekeying your lock is almost always cheaper than replacing a lock. This is because of the cheaper price of the key pins inside the locks, whereas when you replace a lock, you are paying for all brand-new parts.
The average cost to hire a locksmith is $157. You can expect to pay between $98 and $217, depending on the type of service. For example, to change locks for your home, the cost can run anywhere from $50 to $200, depending on how many locks you have, the level of security, and the kind of lock you want.