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.
Locks to Secure Your Home
Caution: the use of a double-cylinder deadbolt lock can be a fire hazard. While occupied a key should be left in the lock and all children should be trained in the use of the lock and all other fire prevention methods.
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.
If you happen to live in an area that sees a great deal of crime like robbery or breaking and entering, a double-cylinder lock might be the best deal. However, if you're in a hot, dry area where house fires are a real threat, this may be an unsafe and impractical option.
Note that “double cylinder” locks (with keys removable from the inside) are dangerous and unlawful. Nearly every year in NYC tenants die in fires because they cannot locate the inside key for a double cylinder lock in a smoke-filled apartment. Such locks are an extreme hazard and should never be installed.
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.
A single-cylinder deadbolt is the most common type. It requires a key to operate the lock from the outside, but has a thumb-turn on the inside.
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.
For one, double-sided deadbolts are the most secure lock. This is especially important if your front door is located near a window that can be easily opened or broken, or if the door itself is made of glass.
Single cylinder locks are more common than double cylinder. The two main reasons for this are efficiency and economy. Single cylinder locks are usually less costly to purchase and install than double cylinders. They are also more convenient, since there's no need for a key to operate the lock from the inside.
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.
Single cylinder deadbolts are quite common in residential homes. Such locks use a key slot on one side with a thumb-turn mechanism on the other side; the key slot generally faces the outside of a door. This system also allows you to unlock and lock single cylinder deadbolts using a thumb turn from the inside.
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.
Even though it may take some time to pick a deadbolt, many burglars are well equipped to handle it with ease. Choose a lock that has a high security cylinder if possible. These locks will have a special pin inside of them, which cannot be picked using a standard tool.
Most criminals who want to get inside your home won't take the time to carefully pick a deadbolt lock—they'll break the glass and reach in or just kick the door in. The fact of the matter is that if someone really wants to get in, they will try very hard to do so.
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.
You might perceive that locksmiths are only concerned with providing safe key entry into your house. This is not the case as they also have the skills to open a deadbolt that has been locked from inside. This means that if you are locked out, you do not need to break a window or door to gain entry into your house.
Having a deadbolt on the entrance to your home will take a standard door knob lock to the next level. Forced entry is involved in 55.7 percent of burglaries, and a deadbolt will make breaking down a door remarkably more challenging.
Grade 1 not only meets commercial building requirements, it also provides the best security available against vandalism and heavy usage. Grade 2 meets light commercial requirements and exceeds residential building requirements. These locks are adequate for lighter duty doors where security is less of an issue.
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.
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.
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.
Schlage and Kwikset are two of the most popular lock manufacturers on the market. Both brands make excellent locks that homeowners can easily install, but Schlage locks tend to offer higher security and reliability and are trusted by big businesses.
Double-cylinder deadbolts can be used with a key from both sides. Vertical deadbolts operate similar to single and double deadbolts, but the lock moves up and down instead of horizontally. This orientation is more resistant to forced entry via prying with a tool such as a crowbar.
A privacy door knob is one of the most common types of doorknobs that have locking functionality on each side. These types of doorknobs have a thumb turn lock or a push-button on the interior knob and a small hole on the other side that can be locked or unlocked with a special key pin.