People install double-sided deadbolts primarily for security reasons. With a single-keyed deadbolt, for instance, a determined burglar could smash a window to reach inside and use the knob to unlock the deadbolt. If the key is not in the interior key slot, this scenario cannot occur with a double-sided lock.
Businesses often use double-cylinder deadbolt locks because they provide more security on exterior doors that have windows. When intruders attempt to break into a building through a window, the key lock on the inside of the door will stop them from entering.
Security — Since a key is required to unlock them from both the inside and outside, double-cylinder deadbolts offer an extra layer of security. Deters burglars — Since they are more difficult to pick, most burglars will move on to an easier target.
The main advantage of installing double-cylinder locks is enhanced security. That's because doors with adjacent windows or glass panels can be broken, allowing intruders to reach inside and unlock the door manually. This is a significant weakness in terms of commercial break-ins and residential burglaries.
Generally, single-cylinder deadbolts are less secure than double-cylinder options. They could potentially allow easier access to the home from intruders in the know. Furthermore, they're easy for small children to use, which means they could get outside without anyone being aware.
In the U.S., there is no single comprehensive law against dual-cylinder deadbolts. Individual cities and states have local property and fire codes that may prohibit the use of dual-cylinder deadbolts. The code may prohibit the use of dual-cylinder deadbolts in some buildings and allow them in others.
CR's take: The Medeco Maxum 11TR503-19 is the strongest deadbolt across all of our lock categories. It's top-notch for drilling, withstands kick-ins very well, and is designed in a way that makes it quite difficult to pick.
Deadbolt Lock Disadvantages
Deadbolts are stronger and more difficult to compromise than other locks, but they're not entirely impenetrable. Break-ins can still happen no matter which type of lock your doors have.
Due to the nature of the mechanism, a deadbolt will always be more secure than a doorknob. If you're reading this from home I encourage you to do a simple test: If you have a door with both a deadbolt and a doorknob, open it and then lock both locks while the door is open.
The answer: One sturdy lock is enough to secure a front door. If installed correctly, a high-quality lock is all you really need. You always have the option of adding a second lock as an extra layer of protection — but there are potentially more productive measures to take. (We'll get to those in just a bit.)
One of the manners in which a deadbolt may be vulnerable to potential burglars is when they are made from certain types of materials. Locks that are composed of a soft metal can be sawed through without a tremendous amount of effort on the part of the burglar.
There are several alternatives to double-cylinder locks. You can replace the glass with shatter-resistant glazing, or back up the glass with shatter-resistant glazing. You can wire the glass to an alarm or, if glass is built into the door, replace it with a solid-core door.
Single cylinder
This is the most common type of deadbolt used. Single cylinder deadbolts have an exterior keyhole that throws or retracts the deadbolt using a key on the outside. On the inside, you can lock and unlock the deadbolt with the thumbturn.
1) EVVA MCS
Each key has a complex rounded shape, this coupled with the magnetic element makes it an extremely hard lock to pick. The only way to gain access to the door would be for the key to be cloned, and in that case, a master locksmith would need to get their hands on the original key.
Most police departments do not recommend double deadbolt locks for residential use. You may be adding additional security at the expense of personal safety with a double cylinder dead bolt. For example, you could lock yourself in and not be able to escape in case of fire or other emergency.
Only the most secure deadbolts earn a Grade 1 rating, by incorporating such features as antipick pins, extra-long bolts in extra-tough alloys, and reinforced strike plates with long screws to secure them to house framing.
A security door differs from a typical door because it is often reinforced with steel or aluminum. These doors feature layers of steel sandwiched in-between wood, making them more challenging for would-be burglars to break.
Deadbolt door locks are the most secure type of key lock and are commonly used on exterior house doors. Single and double cylinder locks are classified by strength from Grade 1 to Grade 3. Grade 1 is the highest and provides the best security.
In combination with your deadbolt, your door will put up a fight against even the most forceful kicks. They're also tamper-proof and will protect your door against lock picking and lock bumping. Even if someone steals or copies your key, they won't be able to get in.
If an intruder is in the home, a double-keyed lock can trap the home's occupants in the home with the intruder. Fire codes in some homes prohibit the use of double-keyed deadbolts on egress doors. In rental houses, it's crucial to take into account the liability of using double-keyed deadbolts.
It is all depending on the deadbolt that you have. If it is a standard lock they can usually just pick it or bump key it. But if it a security lock then the only way that they are able to open it is to drill the lock.
A lock with an ANSI rating of 2 can withstand five strikes of 75 pounds of force before giving way, so an intruder would have to make a tremendous amount of attention-grabbing noise to get in. Replacing a deadbolt isn't hard. But the fact is, the deadbolt is only as strong as the plate the bolt is thrown into.
It's quite easy to pick a deadbolt lock. In fact, you would want to replace all your key locks with electronic ones when you discover how simple it is. This doesn't mean that picking a deadbolt lock does not require skills or practice – it still does – but the technique is so easy that anybody can learn it.
Up to 30x's stronger than standard deadbolts
Ultimate Lock has the ability to withstand up to 4000 pounds of force, to put things in perspective, most deadbolts can only withstand roughly 100-200 pounds of force.