How to choose and size cam locks and latches

Cam lock systems are important cabinet latch hardware requirements. While many enclosures are secured by simple tab style latches, those where access is regularly needed use cam locks and latches. In this article we cover:

How does a cam lock work?
How to choose the correct cam lock or latch
How to determine cam size

How does a cam lock work?

Cam locking involves a metal plate. This is the cam, or cam lock mechanism, which is attached to the locking device. When the key is inserted and turned, the cam – depending on the type of lock – will either drop to the side, which locks the application, or it will rise vertically to unlock.

How to choose the correct cam lock or latch

Before we talk about sizing, we should look at the different types of latches and locks on offer. It can be hard to select the perfect solution for your application, from locks for cabinet doors to industrial door latches. Here we explore some key areas to consider and help to make your selection process easier.

1. Think about cylinder type

The level of security you’ll need for your lock depends on its intended use. Cam locks are ideal for preventing access to applications such as outdoor enclosures for electrical equipment. A more controlled environment, such as industrial manufacturing, could use an easy-to-open quarter turn cam latch. You can also consider the cylinder type, which will impact how the lock is opened.

There are three main systems:

• Keyed alike – all locks opened by the same key
• Keyed different – each lock requires a unique key
• Master system – one master key can open all locks, even if they are keyed different

Understanding your security requirements and who needs to access your locked application is essential.

A cabinet cam latch or lock for cabinets will give you high security. For example, consider adjustable compression cam latches. You can learn more in our Guide to latches.

2. What's your application?

What are cam locks used for? Applications vary. The depth of the door impacts the lock you choose for your application. Depending on depth, you’ll need to pick an appropriate housing that fits the application and offers the functionality you require.

• A cylinder camlock offers a number of housing options as well as many style options.
• If you’re looking for an electrical panel lock, a spring loaded latch, such as a quarter turn is always good.
• If space is limited, go with mini adjustable compression latches.
• If vibration is involved, choose compression latches and locks.

Which cam lock or latch?

Consider these recommendations:

3. Consider style and handling

The style of your cam lock has an impact on how it operates in its application. Think about how you would like to open and close your lock. It might be that a cam lock isn’t your best option for your need. If you’re dealing with a tight space, and security is not an issue, consider a magnetic cabinet latch. Quick and easy to install, magnetic catches absorb the door in an effective manner.

If safety and health need to be considered:

4. Environment

The external environment where your application will be situated plays a pivotal role in the selection of the right cam lock. Cam locks and latches are typically made of stainless steel, nylon or die-cast zinc alloy, which gives it corrosion resistance.

An application, such as an outdoor enclosure will often require an IP or NEMA-rated lock to protect the interior from dust, liquid and moisture ingress. There is no such thing as a weatherproof cam lock, but you can get close to it. When choosing cam locks for cabinets, you'll need to match the NEMA or IP rating of the cabinet or enclosure. The latch rating must match so that the enclosure is not de-rated. You can learn more about these rating systems and how they compare in our guide What are NEMA and IP ratings?

How to determine cam size

There are several dimensions to be aware of to ensure a snug, gap-free fit between the door and the enclosure cabinet.

• In the dimension sizing example below, the head height is the least important factor.
• A hinged electrical junction box or equipment enclosure door will normally mate with the surface of the cabinet or enclosure, often sealing over a vertical lip.
• However, some enclosures are made with recessed doors, making contact with an inner lip built into the box.

In either case, this is one of the first dimensions you need to properly size the cam lock.

• Determine the distance between the outer surface of the door and the inner surface of the enclosure where the cam will make contact. This dimension ensures a snug fit.
• This will determine the housing height, also called the barrel length.

Considerations for cam sizes

• The actual thickness of the door is not usually an issue in metal enclosures because the barrel of the latch is threaded and secured with a locking nut.
• However, the maximum panel thickness may be important if the door is made of wood or other thick materials.

In the above chart, you see the grip range dimensions. Often this is adjustable, and its main purpose is to allow for the gasket used (if any) to seal the door. Note that the grip range has a maximum and minimum grip dimension.

Keep in mind:

• Maximum compression also plays into the snugness of the door to the enclosure’s fit.
• The barrel or housing must be matched to the latch hole in pre-punched doors.
• Most barrels are round and have a threaded diameter to accept the locking nut but are also flat on opposing sides to prevent the latch from turning in the mounting hole.

Cam latch handles

Often the compression can be adjusted when the door is closed by rotating the lock or latch knob. This type of design makes it easier to close the latch and then tighten the seal.

Handles for cam locks come in a variety of configurations:

The configuration you choose is determined by how often the enclosure is accessed, how secure you need the enclosure to be (e.g., authorized personnel only), and whether you need a low-profile latch to prevent damage from, and to, personnel traffic.

You can learn more in our guide Handle design: T, L and pull handles.

How to use a cam lock

You may need to specify a lockable latch, often a keyed one. However, you can use a tamper resistant latch that requires a special tool to open it.

Low profile lift and latch cam locks will add another dimension to consider. Doors that accept these latches will have a rectangular hole cut or punched into them instead of the rounded hole. Take that dimension as well when choosing or specifying your electrical enclosure locks and latches.

Download free CADs and try before you buy

Free CADs are available for most solutions, which you can download. You might also need fasteners. You can also request free samples to ensure the fastener you’ve chosen is exactly what you need. You might also find helpful:

Quick guide: industrial components for outdoor cabinets

Quick guide: the small HVAC components for your design

Quick guide: components for your industrial generator

If you’re not quite sure which product will work best our experts are always happy to advise you. Whatever your requirements, you can depend on fast despatch. Request your free samples or download free CADs now.

Questions?

Email us at sales@essentracomponents.com or speak to one of our experts for further information on the ideal solution for your application 800-847-0486.