Types of Security Seals

The range and different types of security seals and tags can be confusing to the uninitiated, so we have produced the below quick visual guide for understanding some of the key differences, and how particular types of security seals might be suited to use cases in your organisation. For further help and assistance, please contact us at [email protected]



Plastic Indicative Seals, 2 types: (1) Pull-Through Seals seal through locking chamber & pull progressively tighter, suitable for sealing of mail & cash bags; (2) Fixed Length Seals form a fixed loop, suitable where over-tightening might cause accidental breakage in transit (such as trailer hasps).	Security padlock seals are fixed length seals which are small and suitable for sealing of small enclosures like trolley apertures, first aid and other equipment kits, security bag zippers etc. They can easily be sealed and broken by hand for quick and convenient application.	Bolt security seals provide barrier control for shipping containers. They consist of a counterpart barrel and pin with duplicate numbering, sealed together and requiring bolt cutters to remove. They must meet ISO17712 high security standards and are suitable for cross-border customs movements.

Metal Cable seals are strong barrier seals, and in their heavier gauge options (Flexigrip 325M and Flexigrip 500M) are also ISO17712 'High Security' approved for customs movements. The pliable wire cable can be flexibly used to seal through hasps and around vertical locking bars, providing increased security.	Metal strip seals are useful option between plastic indicative seals and heavier duty cable and bolt seals - they provide a higher tensile strength of between 50KgF - 100KgF compared to plastic seals, but are most cost-efficient compared to cable and bolt seals. Their thin straps make them well-suited for sealing small apertures, such as TIR cords and railcars.	Meter wire seals are products suited to sealing utility (gas and electric) & taxi meters. They range from simple plastic and metal seals which can be crimped onto sealing wire with pliers, to more sophisticated self-locking seals with inner mechanism. Wire seals are produced with narrow gauge wire to fit through the small apertures of meters (<1mm).

Tote box plug seals are a specific type of fixed length seals designed to securely seal the lids of attached lid containers (ALC's) firmly shut. Plug seals seal down flush on to lids, making stacking of tote boxes easier, and can also be produced with paired numbering to seal both of end of the crate with the same security number.	Security labels and tapes are their own category of security seals which work on the basis of their tamper-evident film and adhesive properties, rather than by mechanical anti-tampering. By their nature, they are suitable for sealing flat surfaces, such as carton and pallet seams and edges.	Electronic seals are their own subset of security seals which use electronic sensors to detect a tamper-evident state. They are generally reusable seals with a higher initial cost which is spread over many thousands of uses.