Types of Door Locks

You may want to know what door locks you have on your front & back doors, or you’re looking to make sure you have the lock types that will keep you most secure.

Either way, when looking at types of locks for your home or business, the number of options can certainly be overwhelming. 

There are many different types of locks and several different security factors to consider before making the purchase. We’re explaining the different types of locks and the security features that should be considered.


1. Barrel Bolt

A barrel bolt goes on the inside of the door to keep you safe when you’re in your home. This lock has two pieces: one that goes on the door frame and the other main locking assembly that goes on the door.

The main assembly has a cylindrical lock that you can slide into the catch to lock the door from the inside. Some people install two – at the top and bottom of the door – for extra safety.


2. Chain Lock

chain lock

Chain locks are most frequently found on the inside of hotel doors. These locks have a catch on the door frame and a main locking assembly on the door. There is a chain to lock the door instead of a cylinder piece like the ones found in barrel bolts.

The chain lock allows you to open the door slightly but still keep the door closed. 

You’ll be able to open the door to greet someone, but they won’t be able to come in until you close the door, release the chain, and open the door all the way.


3. Deadbolts

deadbolt lock on door

While you may not realize it, a simple doorknob lock is almost useless in keeping an unwanted visitor out of your property. 

Regular doorknob locks are extremely easy to pick or force, and are generally not enough to deter most intruders. A deadbolt, on the other hand, makes it much less likely that a successful break-in will occur.

Deadbolts are considered more secure than the standard spring locks because they can only be opened with a specialized key that rotates the lock cylinder. Deadbolts have several variations, including a single cylinder, double cylinder, and jimmy proof deadbolts.

Jimmy proof deadbolts are popular with double doors because door modifications are minimal. The deadbolt interlocks with the jamb bracket, making it nearly impossible to pull apart or remove from the outside. 

Single deadbolts are found on most front doors and the lock has the keyhole on the outside of the door and an affixed thumb turn on the inside.

Click here to learn more about Carolina Locksmith’s deadbolt installation services.


4. Knob Locks


One of the most common types of locks, knob locks are used on all kinds of doors; front door, bedroom door, garage doors, or rear patio doors. These locks have knobs on both sides – one side has a lock, and the other has a keyhole to unlock the door.

These locks have the locking mechanism within the doorknob. Unfortunately, the knob can be knocked off the door with a hammer, pliers, or the application of enough force, making the fact that these locks are relatively easy to pick almost irrelevant. 

A knob lock should never be used as the only lock on an exterior door. ​ 


5. Lever Handle Locks

door with knob

Lever handle locks are frequently used for inner doors in commercial settings. They are easier to open than knob locks as they have a large push-down style handle instead of a knob to grasp and turn. 

Levers can frequently be the target of torque attacks with excessive pressure applied to the handle to try and force the lock. 

To combat the attacks, some levers are “clutch” levers meaning if they are forced, they turn instead of applying pressure to the lock.

6. Padlocks

residential door lock

Padlocks are the most common type of freestanding lock and easy to identify in a lock line-up. These locks can be used in a variety of ways, and their portable style makes them appealing to many homeowners. 

The very first padlocks were used in ancient Egypt and Babylon, and today we have two main types of padlocks with many other minor variations.

Circular padlocks have a curved bar that protrudes from one side of the lock, moves through the handles on the door, and locks back into itself to prevent the door from opening. They’re also thicker and more challenging to break than a regular padlock.

Key-Based Padlocks require a key to be opened. Some varieties of these padlocks can be rekeyed, and others cannot. 

Keep in mind that if it cannot be rekeyed and you lose the key, your lock will be permanently locked unless you can pick it or cut the shackle.


7. Digital Locks

key card lock

Digital locks don’t require keys to lock and unlock them. Instead, they have a keypad or card system you can use to open the door. They need some form of physical interaction with or proximity to the lock to function.

Many digital or electronic locks do have a combination key system, too, that you can use a regular key with if you forget your code or card key. You’ll usually find these style locks in hotel rooms, schools, and offices.


8. Smart Locks

wireless lock

Smart locks are electronic, like digital locks, and often can be fully keyless. These locks integrate with wireless, Bluetooth, or similar technologies to enable remote access control, usually with a mobile device.

Because most smart lock systems send alerts directly to your smartphone, you can see in real-time if an unauthorized user is attempting to unlock your door. This level of security allows you to take steps immediately to stop their access–even if you’re miles away.

Learn more about Carolina Locksmith’s keyless entry services.


Which Locks Are You Using?​

As technology continues to change and advance, locks may take on an entirely new look and be utilized in a wider range of applications, but the basic function will remain the same. 

Locks have been used throughout the ages and will continue to play a significant role in society as long as people have things they wish to protect.​

At Carolina Locksmith, we understand the importance of protecting not just your belongings, but also your family and your home. Your security is our top priority.  

We have provided commercial and residential locksmithing services since our company started in 1992, and we put our 25+ years of locksmith experience to work to make sure your locks are secure.​

So no matter which of the locks you choose, you can sleep tight knowing that A Carolina Locksmith will keep your home secure. You will be protected by a licensed, experienced, and trusted local locksmith. Check out what others have to say about our work.


  • My dad has been obsessed with everything minimalist and modern lately, and he plans to upgrade several things inside our home, making it a smart home. He told me that he wants to install a smart door lock, but I had no idea about what those are and how they work. What you said about how keyless smart locks are or how you can unlock a door from your fingertips is really interesting! I had no idea that we can now apply this technology to locks. I should share this with my mom so he’s also aware of what my dad is up to.

  • After moving to our current apartment, I’ve been thinking of beefing up its security since it tends to get rowdy around the neighborhood. I like how you mentioned that you can now unlock a door using a smartphone! Since it’s just me and my sister living here, having one of these would be great. I should ask the nearest locksmith for availability once I can afford one.

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