If you need a lock that will automatically lock the door shut upon closing, and require a manual operation to open, slam latches may be what you need.

You are probably already familiar with slam latches, having seen them on the doors of commercial walk-in refrigerators or emergency exits. In this product guide we'll explain what exactly slam latches are, how they work, what different types are available, and their advantages.

In this article we will take a closer look at:

1. What is a Slam Latch?
2. How does a Slam Latch work?
3. Types of Slam Latches
4. Advantages
5. Summary

Slam latches are mechanical devices that allow drawers, cabinets, and doors to be closed securely. This type of latch is spring-activated, allowing its mechanism to fasten without the need to manually secure it every time.

As such, they're great for utility boxes and sliding doors, and since they're usually very rugged, slam latches are especially well suited for industrial and commercial use. These latches are critical in industries where secure closures are synonymous with safety, such as transportation, construction, and aerospace.

In addition, they're exceptionally durable and allow high-frequency usage in heavy-duty areas where continued performance is essential. In comparison to standard spring latches, a slam latch can be opened and closed more frequently without suffering damage to the mechanism.

Here's a video explanation of a slam latch:

Slam latches, often referred to as a push-to-close latch, are spring-loaded latches that utilize a specifically designed spring for tactile resistance. Their basic design involves an enclosed spring mechanism with a sliding pin pushed by the spring, and a separate component with a notch or a curve.

Either the notch or the pin is curved in a manner that allows the pin to slide in only one direction. As the panel door is pushed, or rather slammed, the pin presses against the notch with the curved side, allowing it to glide over. Once in place, the spring will push the pin out, and the angle of the pin and the notch will prevent the pin from retracting, securing the door.

Slam latches usually have a knob, or some kind of a lever that recoils the spring, allowing the pin to be removed and the door opened. There are also quarter-turn slam latches which can be operated by rotating the lever by 90°. Additionally, magnetic cabinet latches use magnetic force to keep surfaces closed while providing a sleeker aesthetic appearance.

Some non-locking latches consist of tension-loaded rollers of plungers and separate strike plates. They keep the openings shut, but offer minimal to no security since they can be opened by applying an opposing force sufficient to overpower the tension of the rollers.

The versatility of slam latches is best reflected in the many different types available on the market. Typically made from industrial-grade materials such as stainless steel, zinc, and high strength plastics, slam latches are often reinforced with a durable coating for added protection against wear and tear.

Each type corresponds to the specific applications and stress loads the latch has to withstand. There are six basic types of push-to-close latches:

• Single point — Single point slam latches feature the simplest design. The pin is encased in the latch housing, with an actuation knob on one side, allowing you to operate the latch. These are non-locking compact latches that are quite easy to install and operate.
• Multi-point — These operate on the similar principle as the single point slam latches but have several slam bolts instead of one. They're a bit more complex to install compared to their single-point counterparts but offer better protection. The actuation mechanism usually comes in the form of a T-handle or a turning knob.
• Push-button — Push-button slam latches are also single-point mechanisms, actuated by a push button that retracts the safety pin, allowing quick access. The safety pins on these latches are curved, facilitating closure by slamming the door. They're single-hole installs, like cam latches, and require very little tools and time to install. They're also suitable for various panel thicknesses.
• Slam bolts — Slam bolts, or finger pull latches, are also single-point mechanisms that require no force to secure the door but have to be operated manually to allow the door to open. They're mostly used to secure non-locking doors, but they can be operated from one side.
• Rotary — Rotary slam latches are the most diverse type. Most of them are designed as single hole installs on the doors rather than panels. As such, you can install them on any door thicknesses that aren't exceeding the overall length of the slam latch. However, they vastly differ in actuation. Key-locking slam latches are usually opened by a key, whether it's a regular flat key or a specifically designed tool. Non-locking door slam latches are usually surface mounted, weld-on components composed of two parts: bolt and locking elements. They're widely applied in various areas, like storage units or refrigeration chambers.
• Paddle latches — Similar to other surface-mounted latches, paddle latches, or flush pull latches, operate via a paddle that retracts the pin from the locking element. As such, they're exclusively two-part components with integrated stops for the self-closing door. They're mostly mounted by using threaded fasteners or built-in into the sliding doors and side panels as flush-mount components.

Slam latches have several advantages compared to draw latches, and their ease of operation is one of them. Unlike draw latches, which are secured and opened by a lever, the functionality of slam latches allows them to close on their own. They don't require any physical force to close, apart from the energy needed to physically lock the door.

However, these can be mounted on sliding and hinged self-closing doors, which eliminates any need to physically move the door to a close. Admittedly, this can cause issues if the door of a storage unit or cold storage closes with you still inside since they're almost exclusively operated from the outside. Larger slam latches, like those used on the doors of cold storage units, have a counter spring that assists the operation of the latch.

This effectively prevents these latches from being opened from the inside of the space they're securing. Most doors of cold storage units have special clamps that prevent the door from closing, ensuring that nobody gets trapped in freezing temperatures.

Slam latches are typically used in refrigeration and as cabinet hardware, which means that they're, for the most part, made of stainless steel to resist corrosion. Zinc-plated options do exist, but these aren't suitable for use in the food industry. Powder-coated latches are better suited for external use, as they're not as pricey as their stainless steel counterparts, and the extra layer of protection makes them better able to withstand weather-related damage.

Lastly, it's worth mentioning that slam latches do an exceptional job of reducing noise and vibration, as long as there's a gasket mounted between the door and the panel opening. This is especially true with cold storage units since the gaskets seal the openings to prevent temperature fluctuations. Additionally, their spring-controlled pin prevents them from opening under vibration or shock load.

Slam latches are devices that allow drawers, cabinets, and doors to be pushed or slammed closed securely, whether manually or with the help of gravity. This is great for applications like securing doors such as emergency exits, or utility boxes. They're robust enough to withstand industrial use in various conditions, including extreme cold, which is why they're mainly used in refrigeration.

However, some variants are exceptionally easy to secure, making them a perfect choice for storage units and larger cabinets. Their smaller counterparts are usually used for securing smaller openings, like windows, fences, drawers, and boat hatches.

If you're interested in finding out more about these latches or purchasing some, visit Reid Supply - a trusted supplier with over 50 years of experience and a variety of available latches and other material. Search by part number, or contact our sales team to help you find the best slam latch for your next project.