The Ins and Outs of Toggle Latches: Selecting the Right Latch

Also known as over centre latches, toggle latches provide an elegant solution to the need to ensure equipment accessibility, and when they’re locked, offer a secure fastening solution for a variety of applications. Using a unique cam action, a toggle latch is stable, strong and dependable, yet the quick release function means it can be opened in a flash.

The wide range of these over centre latch products means there is one to suit most applications, varying from light duty toggle latches that can withstand up to 350kg of force to super heavy duty toggle latches capable of withstanding as much as 7,000 Kg force. The Protex range of toggle fasteners also includes discreet draw latches used on equipment and machinery.

How a Toggle Latch Works

The core principle behind a toggle latch is that of a carefully calibrated cam action that ensures once the latch is closed, it's locked in position. Although a certain force must be exerted to overcome the cam, operation is easy thanks to the leverage provided by the handle, the length of which determines the required force.

Several different terms are used to describe a toggle latch, including over centre fasteners, draw latch, and quick release fasteners, all of which have the same meaning.

Types of Toggle Latch

The Protex over centre latch range ensures there's a model to suit most applications, and they include:

Rigid Claw Latches: 

This is a non-adjustable toggle latch with a rigid claw. These non-adjustable fasteners are used with a variety of catchplates or keeper plates for secure fastening. It's suggested a rubber seal is used to provide some resilience.

Spring Claw Latches:

With the spring loaded toggle latches, the claw is made from curved spring steel that expands as the latch is closed. An alternative option is a claw or mechanism incorporating coil springs.

Adjustable Toggle Fasteners:

On our adjustable toggle latches, the position of the claw can be adjusted using a threaded rod to achieve the required tension. Depending on the type of adjustable toggle fastener, they can allow up to 20mm of adjustment.

Flexible Toggle Latches:

The Protex range of flexible toggle latches incorporate extensible rubber and nylon components that perform the same function as a spring. These toggle latches allow continuous clamping under vibrating loads.

Undercentre Latch:

The undercentre latch is a light-duty latch with a reversed handle, sometimes referred to as a draw latch.

Flush Fitting Toggle Latch

Flush fitting latches are used in panels where a smooth finish is required. These types of toggle latches are often used on vehicle bonnets and hoods.

Protex® Prolatch:

The Protex ProLatch is a special latch that forces a panel or door against a seal and are great for holding firmly in 2 planes. We also have a Junior ProLatch and recessed ProLatch available. 

Protex® Catchbolt:

Protex Catchbolts hold the panel or door firmly in position in three dimensions. These fastening solutions are also available as recessed Catchbolts.

Toggle Latch Applications

When selecting a toggle latch, the maximum load to which it will be subject should be determined. Each latch is designed for a maximum load, and it's suggested to use a safe working load that's half its ultimate tensile strength (UTS). The catchplate or keeper plate strength should equal that of the latch. There are four categories of toggle latches:

Light Duty Latches: 

Ultimate tensile strength varies between 11 kg and 350 kg and these light duty fasteners are suitable for applications such as instrument boxes and cabinets. .

Medium Duty Latches:

Our medium duty fasteners are designed for applications requiring an UTS between 125 kg and 750 kg. Suitable for applications such as machine panels, cases and engine covers.

Heavy Duty Latches:

Heavy duty adjustable latches with a UTS between 1,000 kg and 2,500 kg, suitable for heavy duty applications. 

Super Heavy Duty Latches:

With a UTS of 7,000 kg, these super heavy duty fasteners have been developed specifically to suit the needs of earthmoving and mining applications. 

Locking and Security Mechanisms

Where required, additional locking features can be specified. These might be to prevent theft, tampering or because the installation is subject to excessive vibration that could cause the latch to open. Additional locking features include:

  • Safety catch:  The fastener cannot be opened unless the safety catch is released.
  • Sealing pin:  A spring loaded pin that prevents the catch opening.
  • Padlock:  For added security; a padlock performs the same function as a sealing pin.
  • Keylock:  A discreet keylock incorporated inside the latch.

Toggle Latch Finishes

We supply our range of toggle latches in a variety of finishes, including:

  • Zinc plated mild steel:  Either a silver or yellow zinc plating.
  • Stainless steel:  Barrel polished stainless steel, suggested for outdoor use.
  • Uncoated mild steel(self finish):  Primarily intended for welded attachment and later coating.
  • Electrophoretic black:  Mild steel coated with electrophoretic paint.

The Worlds Number 1 Manufacturer of Over Centre Latches

The comprehensive range of Protex toggle latches, over centre fasteners and quick release draw latches ensures there's a latch suitable for most applications. Contact us to discover how a toggle latch can meet your fastening requirements. Either call +44(0)1527 63231 or email to speak with one of our experts.