Cookies help us deliver our services. By using our services, you agree to our use of cookies.
Email us
Call us
01829 760000
News
A round up of all of the latest Universeal UK news, tamper-evident security industry updates and product guides to make your supply chain more secure.
How Do Cable Seals Work: A Guide to Cable Security Seals
In this article we explore the ‘flexibility of the flexiGrip’ – giving you an in-depth look into our range of metal cable seals used across the world, the benefits of using cable seals for your security, and the wide range of customisation options available to you.
Cable security seals play a crucial role in the transportation process by providing protection and helping to prevent theft, a major concern in the logistics industry.
What are Cable Seals?
Cable security seals (also known as 'cable seals’ or wire rope seals), are flexible, strong types of tamper evident seals popular across many industries, most notably in the freight, transport and logistics industry, but also food / pharmaceutical and manufacturing sectors. They help to reduce theft by posing a physical and psychological barrier to entry, as well as providing clear evidence of tampering should any attempt be made to open cargo enclosures fraudulently.
Cable security seals generally consist of a metal or plastic body, with the cable/wire rope permanently cinched or clamped at one side of the body, with a one-way tamper-evident locking chamber at the other end of the body. The wire rope is inserted into the locking mechanism and gradually tightened to suit the application. The locking mechanism is designed to ensure the cable is securely locked in place, maintaining the safety and integrity of the sealed item. The cable is produced using 'non-preformed' cable which frays when cut open, making re-insertion impossible and providing clear evidence of seal tampering upon visual inspection.
In short, cable security seals provide a strong barrier against fraudulent cargo access, visible indication of tampering, and are used across industries to ensure that containers remain sealed and protected from theft, collusion or fraud.
Why use Cable Seals?
.webp)
The most common commercial uses of cable security seals include securing shipping containers, rail cars, and trucks. These tamper evident seals play a critical role in protecting high value goods during transit by maintaining product integrity.
One of the key benefits of using cable seals is the combination of the strength and flexibility of the wire cable construction. Cable security seals can be tailored in terms of their strength and length so that they are effective for many applications: from a small drum, crate or cage all the way through to sealing of a 40ft sea cargo container.
Cable Thickness
Cable seals, from lightweight 1.5mm diameter to heavyduty 5mm cable diameter
Thinner diameters (<2.5mm cables) are pliable and suited best to small-scale applications, whereas heavier gauge 3, 4 and 5mm cables are much stronger, and can securely seal large-scale applications.
The choice of cable thickness directly impacts the seal's strength and suitability for different security needs. Thinner cables offer ease of use and flexibility, making them perfect for securing items like bags, crates, or smaller containers where high tensile strength is not as critical. Conversely, thicker cables provide enhanced resistance to cutting and tampering, serving as a visual indicator of security making them the preferred option for securing shipping containers, railway cars, and other high-value or heavy-duty assets.
Overall, selecting the appropriate cable thickness and seal configuration is a fundamental security measure that helps prevent theft, maintain the integrity of shipments, and comply with industry regulations. Proper use of cable security seals (combined with regular visual checks) forms an effective barrier against unauthorised access in the logistics industry and beyond.
Cable Security Seals versus Plastic Seals & Cable Ties
Cable seals have significantly higher pulling strengths compared to plastic pull-through seals, which are sometimes used as alternatives. While some of the strongest plastic pull-through seals can withstand pulling loads of up to 50KgF, even our lightest cable security seals are twice as strong. Our most robust barrier cable seals, such as the 325M and 500M models, are over 20 to 50 times stronger than plastic seals! They are also more durable solutions over longer periods of use, as they will not accidentally break in use. Special tools (such as bolt croppers) are required to open these types of seals, so opening the seal is always an intentional decision.
Plastic seals, on the other hand, are designed to be easily broken or cut open with light tools, making them less secure. An even worse solution is a cable tie, which are not suitable for tamper-evident applications because they can be easily undone and re-tied, unlike tamper-evident seal models.
Cable Seal Classification: Security vs. High Security Seals
Another benefit of cable seals over other types of seals are the ISO standards that our range of cable seals are certified to. Security seals are designed to meet international standards such as ISO17712, providing a strong physical barrier against unauthorised access.
The Flexigrip 150M cable seal is certified by the Security Seal Testing Authority (SSTA) as an accepted HMRC customs seal, and for international shipping containers sent by sea freight. Our Flexigrip 325M and Flexigrip 500M seals are ISO17712 ‘H’ High Security Classification and C-TPAT compliant, meaning they are suitable for US customs entry.
High security classification seals are used on cargo containers and rail cars to ensure compliance with international shipping regulations, serving as a barrier and deterrent to unauthorised access. Regular visual checks of seals is important to verify their integrity and compliance with security protocols. There are different seal types, and choosing the right type of seal is essential for meeting security and regulatory requirements. These certifications make cable seals more suited to customs movements.
Industry Applications of Cable Seals
Cable security seals are used across various industries to provide tamper-evident security and protect valuable assets. Key applications include:
Transport and Logistics Industry: Securing shipping containers, trucks, trailers, and rail cars to prevent theft and unauthorised access.
Food and Pharmaceutical: Protecting shipments to maintain product safety and regulatory compliance.
Utility and Energy: Securing access panels, valves, and meters in outdoor and industrial environments.
Industrial and Manufacturing: Safeguarding machinery, equipment, and storage containers.
Retail and Wholesale: Protecting high-value inventory with traceable, color-coded seals.
Government and Military: Securing sensitive equipment and classified materials with top-security, tamper evident seals.
You can also view our guide to the Top 10 Applications for Cable seals here.
Our Range of Cable Security Seals
flexiGrip cable security seals are available in many configurations, including metal or plastic bodies, and in cable diameters from 1.5mm up to 5mm. Each cable seal can be customised with unique serial numbers, permanently laser-etched for traceability and chain-of-custody verification. These seals are constructed from high-quality materials, including options for plastic security seals, to ensure durability and tamper resistance. Choosing the right security seal protects your assets and ensures compliance with security protocols.
Barrier seals incorporate tampering indicators that clearly show if unauthorised access or tampering has occurred, providing both a physical and visual deterrent. Below chart provides an overview of our range:-
Cable Seal Model | Cable Diameter | Load Resistance | ISO17712 Class | Use Cases |
1.5mm | 101kg | Indicative | Road and Rail Freight, Cargo Trucks, Mail Sacks, Roll cages, Drums, IBC’s, Airline Trolleys, Boxes, Cash Bags | |
1.5mm | 259kg | Indicative | ||
1.8mm | 400kg | Indicative | ||
1.5mm | 256kg | Indicative | HMRC Customs, Bulk Tankers, Railway Cars, Valves, Drums, Open Top Barrels | |
2.5mm | 413kg | Security | Bulk Tankers, Valves, Drums, Open Top Barrels | |
3.25mm | 1193kg | High-Security Seals | ISO17712 Customs Movements, High Value Shipping Containers, Bulk Tankers, Industrial Valves, Railway Cars, Heavy-Duty Sealing | |
5mm | 2039kg | As above | As above | |
5mm | 2039kg | As above | As above | |
1.5mm | 256kg | Indicative | Pallet and Crate Security, APHA movements
|
Customisation Options
We also offer a range of customisable options for cable security seals to suit your specific security needs. From varying cable lengths and diameters to different materials and colour choices, our cable seals can be tailored to provide the perfect balance of strength and flexibility. Additionally, custom engraving options such as serial numbers, barcodes, and QR codes enhance traceability and tamper evidence, ensuring your assets remain secure and easily identifiable.
| FEATURE | DESCRIPTION | ILLUSTRATION |
|---|---|---|
| Custom Cable Length | We can produce our cable seals with extra-long lengths, such as 2metres. These long length cables are useful for large-scale valve lockout applications, and for sealing around the vertical locking bars of shipping containers and trailer doors. |  |
| Cable Material | As standard we supply with galvanised corrosion-resistant steel – however, for increased corrosion resistance we can also offer in full stainless-steel cable options, particular suited to marine and maritime applications. |  |
| Custom Engraving | Customisation options are endless, including but not limited to :-
|  |
| Colour Customisation | We offer 12 standard colours as standard, to enable customers to take advantage of colour-coding in their operations |  |
| Counterpart Labelling | We can produce cable seals with counterpart labels for duplicate barcode numbering, for application of labels onto paperwork etc. This can reduce possibility for mistakes due to human error / transcription errors. |  |
| ABS Encapsulation | Available on 325M and 500M models, we can produce cable seals with fully encapsulated ABS overmouldings, protecting the laser-engraved anodised aluminimum surface, for the ultimate tamper-resistant cable seal solution. |  |
Why Choose Universeal?
At Universeal, we understand the importance of reliable security solutions tailored to your specific needs. Whether you require security seals for international shipping or cost-effective indicative seals for retail applications, our expert team can guide you to the perfect product. With a wide range of security seals that meet industry standards, we help protect your assets, streamline compliance, and reduce the risk of tampering.
Please contact us on +44 (0) 1829 760000 or [email protected] for further information, or to discuss your cable seal requirements today.
Top 10 Applications for Metal Cable Seals
We have put together the Top 10 Use Cases for Cable Security Seals, and explain in each case why cable seals are particularly suited for these types of applications.
Cable security seals are flexible and strong types of security seals popular across all types of industries, including freight and transport, food & pharmaceutical, industrial and manufacturing and other sectors. We have put together the below Top 10 Use Cases for Cable Security Seals, and explain in each case why cable seals are particularly suited for these types of applications.
Top 10 Use Cases for Metal Security Seals
| Use Cases of Cable Security Seals | Illustration |
|---|---|
Road Haulage / Trailer Security Cable seals are often used to lock through the locking hasps of road trailer doors, as a stronger solution and more tamper-evident solution than easier breaking pull-through or fixed length trailer seals which can be used alternatively. Our flexiGrip 150M seal is a HMRC Customs accepted seal, and road freight transiting the UK-EU customs borders can utilise customs-accepted cable seals as a cost-effective security seal solution for cross-border road shipments. |  |
Shipping Containers ISO17712 High Security Cable seals are strong barrier seals suitable for sealing of shipping containers transiting customs borders. Cable Seals are sometimes preferred to more conventional bolt seals for shipping containers to provide increased security, particularly for high value shipments involved in food/drink and pharmaceutical logistics: i. Extra-long cable seals can seal around the vertical locking bars, which can provide superior security compared to sealing at locking hasps ii. Our specialised double-locking Flexigrip 500MD is a heavy-duty cable seal which provides a double locking mechanism, for increased security shipments. |  |
Air Cargo Containers Air cargo containers are often subject to vibration, knocks and shocks during air transport and ground movements, and as such lower-strength plastic pull-through seals are not often strong enough to provide effective tamper-evident security. Cable seals provide higher strength security to ensure that seals do not open whilst in transit, providing a full chain of custody of sealed air cargo enclosures from point-to-point. |  |
Rail Cars Cable seals are ideal for sealing individual rail freight car doors. Our range of cable security seals have rugged design features to ensure chain of custody during rail freight movements. |  |
Intermediate Bulk Containers (IBCs) Light-weight cable seals with smaller apertures, for example 1.5mm cable diameters (100S and 150M Models), are suitable for sealing through apertures in Intermediate Bulk Container outlet points. Cable seals seal IBC’s against unauthorised or illegitimate access and maintains the chain of custody of full and empty IBC’s whilst transiting through the supply chain. |  |
Postal and Mail Sacks and Bags Cable seals are well-suited as high-strength pull-through security seals, where the application in question demands increased strength or tamper-evident security. For example, mail sacks might contain particularly sensitive items or cargo requiring the additional strength and tamper-evident protection of cable seals. Cable seals can withstand over 2000KgF of pulling strength force (depending on model) and will not break in transit accidentally. |  |
Bulk Tanker Hatches, Manholes and Valves Chemical and fuel bulk tankers often have multiple points of access, and cable seals are an excellent way to seal these points of access so that legitimate users can maintain an audit and chain of custody of when, how and where tanker contents have been accessed. |  |
Open Top Barrels and Chemical Drums Cable seals can provide a strong tamper-evident lock to sealing the metal clasp mechanisms of open top barrels, ensuring drums remain sealed until delivered to customers, or received back to depots etc. |  |
Valve Lockout Cable seals, sometimes known as “car seals” when used in the context of valve lockout applications, can provide a safe and effective way to isolate valves of all kinds, including quarter-turn, 3,4,5-way valves, gate valves, and butterfly valves. Car seals / cable seals can prevent the actuation of equipment, assisting in isolation and inspection programs. |  |
Pallets & Crates Our StrapSecure cable seal and pallet strapping solution is a convenient and cost-effective way to seal the intersection of strapping which can be used to seal pallets and crates being transported through the supply chain. StrapSecure is particularly suited for sealing of APHA agricultural and pharmaceutical consignments, as they provide security on the individual pallet-level. |  |
See our full range of cable seals for more information.
Please contact us at [email protected] or +44 (0) 1829 760000 to discuss your cable seals requirements today.
Display
per page
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]
 | .png) | .png) |
| 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. |
Our friendly and knowledge team would be happy to discuss your security seals needs - please contact us at [email protected] or +44 (0) 1829 76000.
Choosing the Best Security Seal for the Job
With the range and breadth of security seals on the market, it can be very challenging for the uninitiated to know which seal to choose to best suit their needs. From the outset, it is recommended that the decision-maker considers the purpose of the security seal in relation to the application. Considering some of the fundamentals from the outset will help to select the right seal for the job…
…why is the user sealing the enclosure in the first place? Is it for loss prevention, safety purposes, product integrity, brand assurance...?
…what type of goods will be protected? What is the value of the goods?
…where is the seal going, and how? Cross-border shipments are subject to customs regulations which will affect the seals that can be used
…what kind of resistance is required? What are the consequences should if the security seal has been broken or tampered with?
…what environment is the seal being used in? What is the operating temperature? How long does the seal need to last for?
Answers to these questions will have a bearing on the material, form, shape, strength of the most appropriate security seal.
It should also be noted that a security seal alone cannot provide an iron-clad guarantee of integrity. No manufacturer anywhere in the world can say with complete certainty that – given enough time, appropriate circumstances, resources, skills and ingenuity – their security seals are undefeatable... but this is also true of safes, door looks, padlocks and alarms. Security seals should always be used as one layer within an ‘onion skin’ of security (view our guide to security protocols).
With this said, below we note some key characteristics of seals you should consider when choosing the most suitable. Try out our handy filtering tools shown on our main security seals category to find a product matching your needs.
| Seal Feature | Considerations |
|---|---|
| Design Type | Seals come in many forms... Pull-through Security Seals, Fixed-Length Security Seals, Security Padlock Seals, Barrier Seals (Cable Seals and Bolt Seals), Wire/Rope Meter Seals, and even Reuseable Electronic Seals. Security seals also include security tapes and labels, suitable for flat surfaces and edges on enclosures such as crates, cartons and pallets. Each type is designed for particular types of applications - for more information, see types of security seals. |
| Physical Fit (Diameter, Length and Flag Size) | Each security seal will have a particular tail or hasp diameter, an effective useable length, and a standard flag size for visibility of printed identification markings. Narrower seals are useful where seals must fit into smaller apertures, and for this many of our pull-through seals have smaller diameters, such as the MiniLock 570's 1.4mm tail thickness and UniTite 414's 2mm thickness. We also offer extra long seals, such as the UniStrap 412-XL (overall 51cm length) and UniTite 413 (overall 49cm length). In terms of flag size ("marking area"), we offer specialised security seals such as our UniFlag Security seal, which has a large format (108x56mm size). |
| Material | Common materials in use for security seals are polypropylene, nylon, aluminium and steel. Polypropylene is a popular choice for pull-through seals, as it offers a combination of strength, flexibility and wide operating temperatures. However, all types of plastic do become brittle at increasingly low temperatures, and do degrade when exposed to UV light, long-term saltwater exposure, solvents etc. Metal aluminium and galvanised steel cable seals provide more durability and strength where circumstances dictate, and we can also specify stainless steel cable grades for most demanding applications: see our Flexigrip 150M and Flexigrip 325M models. |
| Strength | Seals are specified for particular strengths – for certain applications such as fire extinguishers, kit bags and first aid trolleys it is desirable to have a very low break-strength so that seals can be broken in an emergency – for others, for example mail sack security seals, it is important that seals with strong break strengths are used so that bags do not burst open when under tension. There is a wide range of tensile strengths available, from 5KgF all the way up to 2000KgF, so understanding the possible forces relevant for your application is important for specifying the right kind of seal. |
| Level of Tamper-Evidence | We categorise our security seals as having either a Low, Medium or High degree of tamper-evidence, based on design and construction features, method and material of construction, and level of certification. |
| ISO Classification | Linked to the above, higher levels of security seals are often required for international freight movements - in particular, High Security Seals as classified under ISO17712:2013 regulations for international shipping container and freight movements. |
| Removal Method | Some applications require easy-access into a sealed enclosure, and for this we have security seals that can be removed easily by hand, either with low-break strengths (see our Fireseals) or tear-line features (see our Tracewaste Tear-Off and UniStrap 412LT). For other requirements, security seals need to be robust and should not be removed intentionally without simple tools such as scissors or tin-snips, such as our UniTite 413. In other scenarios, particular for barrier seals, we have our heavy-duty cable and bolt seals, products such as our Flexigrip 325M, Flexigrip 500M and Fork seals which necessitate the use of heavy-duty cutting tools like bolt croppers to remove. |
| Sustainability | Sustainability should of course be at the heart of every business, and security seals should be no exception. All of our plastic security seals are 100% recyclable, and we are increasing options for recycled content and biodegradable security seals on a regular basis. |
Universeal UK has been supplying security seals since 1992, and we are one of the leading organisations in the industry. Please email [email protected] for more information on our range and how we can assist. For advice on using security seals within a wider security program, please continue reading our next article in the series, Security Protocols: Making Security Seals work for You.
This article is the second of four, looking at how security seals can fit within your wider security protocols. View Series below...
- What are Security Seals?
- Choosing the Best Security Seal for the Job
- Security Protocols: Making Security Seals work for you
- Glossary – Understanding security seal terminology
Cargo Security: Sealing Vans, Trucks and Trailers
Securing your assets against theft and interference whilst in transit is more important than ever in our globally-connected world. Security seals are an important part of the security process; helping to ensure that your goods arrive at destination as expected, without delay.
Security seals come in various forms to suit particular applications, and in this article we run through the different types of seals which are suitable on various forms of road transport vehicles.
Transit and Small Van Security | |
 | Security LabelsSmall transit and other small courier vans do not feature locking hasps or other features which would allow for sealing by way of an indicative pull-tight or fixed length seal. Instead, non-residue security labels can be placed on the seam of vehicle doors, preventing access without removing the label and de-facing the surface, leaving a VOID message through the seal. Non-Residue labels have the advantage in that they do not leave a residue on the surface of the doors, avoiding damage to paintwork. |
Vans with Roller Door Shutters |
|
 | Indicative Pull-Tite SealsVans and other vehicles with roller-shutter doors feature hasp and staple-style locking arrangement. For these types of locks, we recommend use of a pull-tite or “pull-through” tamper-evident seal, which can be secured tightly around the mechanism, preventing interference by opportunists. Pull-through seals are available in many different sizes and configurations. We hold most items in our UK warehouse; alternatively, we can customise with your bespoke marking, logo and custom numbering. |
Articulated Lorry Trailer Doors | |
 | Fixed-Length / Ring SealsTrailer doors are available with a number of different locking mechanisms, and so the preferred security seal will depend on the mechanism in question - either pull-through or fixed-length seals are recommended. Fixed-length or "ring" seals, form a secured loop through a locking aperture. Ring seals do not “pull tight” around the locking arrangement, meaning that they can be freely rotated, checked and inspected for signs of tampering more easily. |
Curtain-Siders | |
 | Fixed-Length Seals and TIR CordsCurtain sided trailers are best secured using a TIR cord to pass through each of the buckles along the trailer, looping around so that TIR fasteners can be secured at the back of the vehicle using a plastic indicative fixed-length seal. This ensures that the only way to access any side of the trailer is by way of breaking the seal, providing the audit trail required. |
Containers on Trailers | |
 | High-Security Bolt Seals & Plastic Indicative Seals (empty loads only)Fully-loaded shipping containers which are being moved internationally require sealing by way of a security seal designated and tested as ‘high-security’ according to ISO17712 and CT-PAT regulations. Our high-security bolt seal is one of the most well-established on the market and fully compliant. For empty loads, we recommend use of plastic indicative seals – providing peace of mind that empty containers have not been accessed against the knowledge of the legitimate user, reducing risk of foul play. |
Open Top Containers |
|
 | TIR Cords & Plastic or Cable SealsOpen Top containers allow bulky items to be loaded directly from above. They usually covered and secured using a tarpaulin. TIR cords should be used to pass through the tarpaulin cover eyelets and around container corner posts or lashing rings. The TIR fasteners can then be secured with a security seal – either an indicative plastic seal, or where the goods are being shipped internationally, a high-security bolt seal or cable seal. |
Oil, Gas & Bulk Liquid Tankers | |
 | Flexible Cable SealsThe valuable and potentially hazardous contents of tankers are at risk of interference, theft and fraud, especially whilst in transit and away from the legitimate user. This makes it crucial that sensitive and valuable access points, such as valves, meters and hatches are strongly secured against tampering. Flexible, variable length and very strong cable security seals are ideal for ensuring such access points are secured against interference. |
Universeal is happy to explore suitable van, truck and trailer security solutions for your business- please contact us [email protected] or 01829 760000 to discuss your requirement for security seals and we should be happy to help.