For example if there s a window on or nearby the door think of sidelight windows next to a door for example someone could break the window reach in and turn the deadbolt of a single keyed lock.
Single vs double cylinder door lock.
Double cylinder deadbolts or handlesets require a key for locking and unlocking from both the exterior and the interior of the property.
Double cylinder door locks.
On the other hand single sided deadbolts require key to unlock from the outside only.
Instead the door is unlocked with a thumbturn style lever.
While the single cylinder deadbolt only features a locking mechanism requiring a key on one side the double cylinder deadbolt has it on both.
The single cylinder deadbolt is the most common.
This difference has one primary trade off.
A double cylinder deadbolt has no thumb turn.
This prevents intruders from entering and exiting easily.
Instead the door is locked or unlocked using a thumb turn style lever.
It is found on front or back exterior doors and requires a key to open it from outside.
A simple thumb turn locks and unlocks the door.
This term generally refers to the deadbolt section of a handle set or to the individual deadbolt itself.
Double cylinder deadbolts entry knobs and handlesets require a key for locking and unlocking from both the exterior and the interior of the property.
Single cylinder locks have only one lock cylinder as the name implies.
A single cylinder has a keyed entry on one side while a double cylinder has keyed entries on both sides.
Double cylinder deadbolts are locks that require a key to open from both the inside and outside.
This means that a key will be required to turn the lock both on the inside of the door and the outside.
Double cylinder locks is the number of cylinders.
Doors outfitted with single cylinders are unlocked with a key from the outside but do not require a key for unlocking from the interior of the property.
Single cylinder deadbolts and handlesets are operated with a key from the outside but do not require a key for locking or unlocking from the interior of the property.
Just like single door locks you will also require to use the key to lock the door.
These locks require a key to lock or unlock the door both from the outside and the inside making them a little safer in one regard.
A thumb turn opens it from the inside.
A double cylinder lock also has a key on the inside which is required to operate the deadbolt.
It means that you will need to use the key to unlock the door no matter which side you are on.
Single cylinder locks are usually less costly to purchase and install than double cylinders.
The difference is that you need to lock the door from both inside and outside with the key.
Double cylinder locks contain two cylinders.
All deadbolts have a key on the exterior side for security.
Single sided deadbolts have a knob on the inside that is used to unlock and lock them from the inside.
They are also more convenient since there s no need for a key to operate the lock from the inside.