Door Lock Types: How to Choose the Right One for Your Home
Most homes need two kinds of lock: a latching knob or lever set for everyday use and a deadbolt for real resistance on exterior doors. Beyond that, the right choice depends on the door’s job. An exterior door needs security, a bedroom or bathroom needs privacy, and a hallway door needs no lock at all. Smart locks, mortise locks and sliding door locks fit specific situations, and the sections below show which.
TL;DR
Exterior doors need entry hardware, and a deadbolt belongs on top of any knob or lever lock. Interior doors use privacy or passage hardware.
Deadbolts project at least 1 inch into the frame, which is why they resist force better than a spring latch.
Check the ANSI grade (Grade 1 is the highest), plus door thickness, bore-hole size and backset, before you buy.
Smart and keypad locks add convenience, but they run on batteries and carry digital risks.
A professional installer or rekey can save you from a mismatched lock and a door that will not latch.
Table of Contents
How door locks are grouped
Walk into a hardware store and the wall of locks can look random. It is easier to read once you sort it by the door’s job. Lowe’s buying guide splits hardware into entry, privacy, passage and dummy types, and that is the most useful way to start.
Hardware type | Where it goes | What it does |
Entry | Exterior doors | Locks with a key, giving security from outside |
Privacy | Bathrooms, bedrooms | Basic lock, usually a thumb turn or push button |
Passage | Hallways, closets | Latches but does not lock |
Dummy | Closets, pantry doors | Handle only, no latch or lock |
The same guide notes that entry hardware is the one built to secure exterior doors, while privacy hardware covers bathrooms and bedrooms and passage hardware covers interior doors that do not need locks. Within those groups you will see keyed knobs, levers, handlesets and deadbolts. Other lists that rank well for this topic add cam locks, mortise locks, keyless entry locks, smart locks, Euro profile cylinders and padlocks, as in this roundup of common door lock types.
So how many types are there? It depends on whether you count by mechanism, by mounting style or by how the lock is operated. For a homeowner, five or six families cover nearly every door in the house.
Deadbolts: the lock most exterior doors need
A deadbolt uses a solid bolt that you move by turning a key or thumb turn. Unlike a spring latch, it does not retract when pushed. The USDA Forest Service’s physical security guide says deadbolts project at least 1 inch into the doorframe and resist pressure on the bolt itself. That depth is the main reason they are the standard recommendation for front and back doors.
A security expert quoted by Family Handyman calls deadbolts stalwarts of home security and says knob locks on exterior doors should be complemented with one.
Single-cylinder vs. double-cylinder
A single-cylinder deadbolt has a key on the outside and a thumb turn on the inside. A double-cylinder deadbolt needs a key on both sides. It can make sense where there is glass in or next to the door, because someone who breaks the glass cannot simply reach in and turn a thumb turn. The same federal guidance says a double-cylinder deadbolt should be used where glazing is in or beside a door, but must never be used on an emergency exit or on a door that serves as one.
That last point is a safety matter, not a footnote. In a fire, nobody should be hunting for a key. If you keep a double-cylinder deadbolt, decide in advance where the key lives and make sure every adult in the home knows. If a glass panel next to your door is ever cracked or smashed, securing broken glass safely until it is repaired is worth doing before anything else, since that glass is exactly the weak point a double-cylinder deadbolt is meant to cover.
Knob locks and lever locks
Knob locks are the most familiar type. The lock cylinder sits in the knob itself, and the glossary published by a New York state agency notes that they are frequently installed on residential exterior doors alongside a deadbolt. That pairing is correct. The knob lock keeps the door closed day to day, and the deadbolt provides the security.
The Forest Service guide is blunt about the limits: cylindrical locks, including key-in-lever sets, are very low-security. That does not make them wrong for the job. It means you should not ask a knob lock to do what a deadbolt does.
Lever handles work on the same principle with a different shape. Lowe’s notes that levers are easier to operate than knobs, needing less grasping and wrist twisting. That matters for children, older adults, anyone with arthritis, and anyone carrying groceries. Many homeowners choose levers for accessibility alone.
Handlesets and mortise locks
A handleset combines a grip handle, a thumb latch and usually a separate deadbolt in one matching package. Lowe’s describes handlesets in right-handed, left-handed, reversible and universal versions. Handing matters: a set bought for the wrong side may not fit your door’s swing.
A mortise lock sits inside a pocket cut into the edge of the door. You find them on older homes and historic properties, including many of the brick row houses and early-1900s houses across Wilmington and New Castle. The federal security guide says mortise locks are recessed and can weaken the door where the pocket is cut. In practice, a well-made mortise lock can be very sturdy, but repairs and replacements are specialized work. Parts are not always interchangeable, so it is worth having an experienced locksmith look at one before you swap it for something modern.
Rim locks, drop bolts and other surface-mounted locks
These show up less often on modern homes, but you may meet them on older doors, garages, outbuildings or as add-ons. According to the federal guide, rim-cylinder locks are surface-mounted on the interior side of the door and are commonly paired with auxiliary locks such as drop bolts. A drop-bolt lock has interlocking leaves on the lock body and the strike plate, with locking pins that hold them together, which makes the pair extremely difficult to separate.
They are a reasonable choice for a secondary layer on a shed door or a back entrance, where you want strength without drilling a large hole through the door.
Keypad and smart locks
Keyless entry locks replace the key with a keypad. Smart locks go further and can offer remote access from a smartphone. Some keyless models require batteries, so plan a reminder to change them rather than finding out at the door.
Consumer Reports sums up the trade-off: smart locks bring convenience and integration, but may be vulnerable to digital hacks. The practical way to use that is to buy from an established maker, keep the firmware updated, use strong unique codes and avoid obvious ones such as birth years.
Who benefits most from a smart lock?
Families who want to give children or visitors temporary codes instead of copying keys.
Short-term rental owners who need to change codes between guests. This is common at the beaches, where busy summer weekends mean frequent turnover.
Anyone who has lost keys before and wants a backup way in.
A keypad or smart deadbolt still needs a sound door and frame. A strong lock in a weak frame is only as secure as the frame.
Locks for sliding doors and patio doors
Sliding glass doors are a common weak spot, and they use different hardware. On a typical sliding door, a hook moves to latch onto another hook inside the doorjamb, as Family Handyman describes. The same source says Euro profile cylinder locks suit patio and sliding glass doors.
If your slider has only the factory latch, adding a secondary lock is one of the least expensive upgrades you can make. A locksmith can match a secondary lock to your door’s frame and track so it sits properly.
Which lock for which door
Use this as a starting point.
Door | Typical lock | Notes |
Front door | Deadbolt plus entry knob, lever or handleset | Choose a high ANSI grade |
Back door | Deadbolt plus entry hardware | Consider double-cylinder only if glass is nearby and it is not an emergency exit |
Garage entry door | Deadbolt | Treat it like an exterior door |
Sliding door | Latch plus secondary lock | Euro profile or track-fit option |
Bedroom | Privacy lever or knob | Thumb turn or push button |
Bathroom | Privacy lever or knob | Make sure you can release it from outside in an emergency |
Hallway, closet | Passage or dummy | No lock needed |
Shed or outbuilding | Rim lock, drop bolt or padlock | Secondary layer |
For bedrooms, Lowe’s says doors typically use privacy hardware with basic locks, and the knob or lever may use a thumb turn or push button to engage. Privacy locks are designed to keep someone out for comfort, not to stop a determined person. If you have young children or elderly relatives at home, choose a model that can be opened from the outside with a small tool, so you are never locked out of a room where someone needs help.
What to check before you buy
The lock aisle rewards a little preparation. Here is what matters.
ANSI security grade. The American National Standards Institute grades locks, and per Lowe’s, Grade 1 is the highest security, Grade 2 is mid-level and Grade 3 is basic protection. For an exterior door, look for Grade 1 or Grade 2.
Door thickness. Most hardware is made for a standard range. A thicker or thinner door may need a different latch or an adapter.
Bore-hole size and backset. The same guide tells you to check the door’s thickness, bore-hole size and backset. Matching the existing latch or bolt configuration makes installation far simpler.
Handing and finish. Make sure the handle matches the swing and that the finish suits your other hardware.
Key control. If you rent out a property or manage a building, ask about restricted keyways, so keys cannot be copied at any corner kiosk.
Frame and strike plate. A longer screw into the framing will do more for you than a fancier lock.
If any of these measurements make you uncertain, it is cheaper to have them checked before you buy than to return an ill-fitting lock afterward.
Our perspective on door locks
Most of the calls we get are not about exotic equipment. They are about a lock that was never right for the door in the first place: a knob set standing alone on a back door, a worn deadbolt that no longer throws all the way, or a lock installed so close to the edge that the frame has split. Our view is simple. Pick the lock for the job, install it correctly and keep your keys under control. A Grade 1 or Grade 2 deadbolt in a properly reinforced frame will do more for a home than an expensive lock installed badly. If you have just moved in, or you have had keys go missing, rekeying is often a practical first step because it makes old keys useless without replacing the hardware. We work as a mobile team across Delaware, so we bring the tools to the door instead of asking you to haul a lock to a shop. You talk with us directly, not with a call center, and we would rather explain your options plainly than sell you more than you need. For homes, rentals and small businesses alike, that means rekeying, new installations, high-security lock upgrades and smart lock setups done on site. Brian
Getting the right lock installed
We offer residential locksmith work such as home lock rekeying, new lock installation, smart lock upgrades, high-security lock upgrades for homes and rentals, and help when you are locked out of the house. For businesses, we also handle master key systems, access control solutions, panic bar installation and door closer, hinge and frame hardware repair. You can read more about our residential locksmith services or see the full list on our locksmith services page.
If you are unsure which lock suits a door, call us before you buy. We will look at the door, the frame and how you use the entrance, then tell you what fits. Reach us through the Local Locksmith & Car Keys Delaware site to request mobile service at your address. Running a shop, office or rental? Our commercial locksmith services cover the same work at business scale.
FAQ
What are the most common types of door locks for homes?
Deadbolts, knob locks, lever locks and handlesets are the most common on houses. Mortise locks appear on older homes, and keypad or smart locks are increasingly added to newer ones. Sliding doors use their own hook latches, often with a secondary lock.
Which lock is best for a front door?
A Grade 1 or Grade 2 deadbolt paired with an entry knob, lever or handleset is the usual setup. The deadbolt provides the resistance, and the handle provides everyday latching. Make sure the strike plate is anchored into the frame with long screws.
Which lock should I use on a bedroom door?
Use a privacy knob or lever with a thumb turn or push button. These are designed for comfort and privacy, not for security. Choose one that can be released from outside with a small tool, so you can always reach someone inside in an emergency.
Are smart locks safe?
Smart locks add convenience, such as remote access and temporary codes, but Consumer Reports notes they may be vulnerable to digital attacks. Buy from a well-established maker, keep the firmware current and avoid easy codes. Keep a physical key backup in case the batteries die.
Is a double-cylinder deadbolt a good idea?
It can be, when there is glass in or beside the door, because it stops someone from reaching in to turn a thumb turn. It must never be used on an emergency exit or a door that serves as one, since you would need a key to get out. If you are unsure about your layout, have a locksmith assess the door.
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