Door Lock Guide

You never really think about it, but something as simple as a door lock is the barrier between you and the outside threats of the world. Locks enforce safety and maintain privacy. It should go without saying, but efficiency is not something to ever compromise on when making your lock selection.

door locks

Every year, around 2 million residences are broken into. So understanding the key differences between available locks can help you choose the appropriate one for your home, workplace, or facility. Or, if you are a locksmith, or in the lock installation industry, knowing these details will allow you to help your customers make informed choices of their own.

Explore our guide below to learn about the five main types of lock.

Knob Locks

Knob locks are the most common type of door lock and the foremost method of security for most doors. The lock cylinder is located in the knob instead of the door. Thus, knob locks should not be used on external doors, as they can be broken into with basic tools like a hammer or wrench.

Cam Locks

Cam locks get their name from the various tailpieces or “cams” which create their locking mechanism. They are a type of fastener that allows storage to be kept in a subtle way, without disrupting the lock’s appearance.

They are, for the most part, invisible in fully constructed cabinets. Cam locks usually come with sets of furniture and cabinet kits. These locks are cylindrical and are situated in the wood. A metal tube with a hole in one side helps position the bolt that is inserted. Certain cam locks secure cabinet doors completely, which make them particularly handy for protecting sensitive contents.


Deadbolts offer the best protection against a break-in. The bolts are moved by turning a knob or a key without the use of a spring. This unique locking mechanism resists physical attacks, battering and drilling. A deadbolt also cannot be opened with a knife or hand tool.

Deadbolts come in three types: single, double, and C. Single cylinder deadbolts are the simplest, using a key which works from one side. A double cylinder deadbolt can be used by somebody with a key on either side.

Single and double deadbolts can feature a thumb turn that locks from the inside with a key. This type of deadbolt provides the greatest degree of flexibility and security.


Padlocks belong in the free-standing lock group. They are portable, meaning unlike other locks, they aren’t permanently attached to what they affix to while in use. Padlocks come in a variety of models that are grouped into two categories: keyed and combination.

Keyed padlocks alone are available in different sub-types, such as keyed alike, keyed different, and key-able. Padlocks are easy to recognize, not just because their mobile nature, but also their distinctive loop handle which resemble shackles. The lock’s “shoulders” raise the sides of the shackle to inhibit bolt cutters from piercing through.

Mortise Locks

Mortise locks are powerful when used on external doors. However, they are available in both light and heavy duty models. They are comprised of an internal system which makes them more lock set than just lock.

Mortise locks house either knobs or levers, as well as a cylindrical body. They are threaded and use mortise components within the door. A box lock is set within the mortise, which is a deep recess in the edge of the door.

Mortise lock-sets stay secure by using a set screw and a cam which creates the locking mechanism. The cylinder component comes in various heights and lengths for different types of doors.

Lock Type by Security & Use

Feel knowledgeable yet? While a variety of lock styles exist, most locks still fall under at least one the five staple categories. Some locks even overlap categories. For example, lever handle door locks are used for inner doors and have similar mechanics to knob locks.

Beyond taking appropriate security measures, there are two other things to keep in mind when finally selecting your lock. The first is the backset, which is the width from the center of the lock’s hole to the edge of the door. Measuring the back-set of a door determines if your lock will fit it properly. The second is door handedness. What this refers to is whether the door will swing towards or away from you when opened.

To check if the door is left handed or right handed, take a peak at the hinge. Right-aligned hinges mark a right-handed door, which will swing away and towards the right, while left-aligned hinges mark a left-handed door, which will do the opposite. (Deadbolts, to reiterate lock variety, can be installed on doors of either handedness without issue, whereas this is not the case with every lock.)

So, with all these considerations to keep in mind, make sure to do your research before investing in your lock.