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Guide to Cable Seals: Effectiveness and Application

More robust cable seal specifications meet ISO 17712 ratings for high security, so they can be used for high-security situations like international cargo shipping. Different size jobs require different lengths and widths, although excess cable length can be easily trimmed. They also come in different cable diameters, typically ranging from 1.5mm to 5mm.

Trucks and trailers involved in the international transport of goods are subject to strict customs regulations. The type of seal to be used will depend on whether road only or multimodal transport is involved as the security requirements for each security seal vary depending on application, industry and type of goods. This guide for cable seals will help to provide insight and enhancement for the selection and deployment of high-strength barrier seals.

Industrial Application

When trucks are part of a multimodal transport process, their cargo is placed in containers to ensure a fast and compatible transfer between different modes of transport such as a shipping freighter to HGV. High security seals are used as a tool to deter and detect unauthorised access of any vehicle or container during its movement through the supply chain. They differ from locks in that they are intended to be used only once, and then removed and responsibly destroyed. The most commonly used seals are high security barrier seals: adjustable cable-type seals or fixed bolt seals.

Early seal products were intentionally made to be easily cut open after use to be user-friendly. However, due to increasing security demands, the added dimension of a high strength barrier seal became popular in transportation and logistic industries. Now, some security seals function both as a strong disposable lock and a tamper-evident seal — providing both a visual indicator and an barrier to entry.

Sophisticated methods of seal violation can occur in various forms: hiding the breakpoint to fool the observer, seal substitution (cloning) and modification of print markings. The initial discovery of tampering usually occurs when the vehicle reaches its final destination and the seal is cut and taken out of use. It may also be found on examination of the seal after it is opened by the user and checked at another location. If not examined by a trained and experienced inspector, tampering or violation of the security seal may not be discovered at all.

Application Effectiveness

Seals alone cannot protect cargo containers and other closures from access by motivated people who intend harm. However, each step toward improving seal technologies will help to improve the detection and prevention loss ratio and reduce points of opportunity for nefarious organisations and individuals. Security seals can be made to work effectively in tamper detection but naturally require a strong and well-enforced program for control and inspection and deliberate and adaptable countermeasures to be as effective as possible.

With today’s concerns of fraud and terrorist acts, security seals have become a more common tool as part of programs to identify a container of goods opened after its sealing point. However, the added challenge of immediacy requires a much higher degree of knowledge, control, and attention to the seal throughout its use. In addition to more control and inspection, immediate discovery may also require the use of more than one device and method.

There are many techniques employed to make a security seal more effective as part of any transportation chain. All procedures must be backed by real consequences and personal responsibility. It is important that seal users are always evaluating and improving their own measures to enhance the effectiveness of seal application. Outlined below are some procedural guidelines that can be taken to make tamper evident seals useful and effective:

  1. Layered Technology: This consists of combining security devices to build a complete process of protection measures. For example, the deployment of multiple tamper evident seals and different types of seals (both indicative and preventative). This could also include enhanced visual ID, such as print indicators to show the time of locking and driver responsible (RFID).
  2. Multi-Step Inspection Process: Training people to be as conscientious as possible throughout the transportation process is key to ensuring a comprehensive inspection of cargo. If vehicles are transporting over several hours or even days period, consider inspection stops for the driver to assess the cargo.
  3. Seal Variation: Colours and alpha-numeric combinations can be varied on a rotating basis which will limit the potential for planned seal cloning or replacement. Model, size and style can also vary from time-to-time to ensure the procedure does not become predictable and easily exploited.

Terminology and Seal Classifications

There are two general seal types, but 3 categories in today’s official government terms. The two main types are:

Indicative security seals (HMRC Group 3) serve the function of providing visual evidence but are easily broken or cut open with light tools. These are also referred to as tamper-evident seals as they mostly provide discernible evidence of unauthorised access as opposed to a preventative measure.

Barrier seals (HMRC Group 2 and 1) are higher strength security seals that can provide tamper-evidence and serve as a one-time lock to slow down and deter theft or vandalism. They require large tools to cut open, preventing access at a much higher level compared to seals removeable by hand.

Many still do not understand the standards and regulation surrounding security seals and therefore often do not select or apply their chosen seal optimally. High Security seals must comply with ISO/PAS 17712 regulation and, for the United States, C-TPAT. In this regard, we highlight two types of models available from JW Products which meet the highest standards of international regulations: the 3.5mm Cable Seal and the HMRC Bolt Seal.

You can read our full breakdown on ISO 17712 regulation by reading our Security Levels and Classifications guide.

Determining your Requirements

You must first consider if an indicative or barrier security seal is required, and what strength level is best. Any industry that moves hazardous contents and transports goods through customs and ports may have strict regulation on their movement and must consider the international standards of sealing (ISO 17712).

Also, consider costs relative to the security risks for your application. It is quite common to invest too little or too much in seals and this may lead to a security process that does not fit your business requirements. Some of our other recommendations before choosing a seals is to:

  • choose a seal type that physically fits the device or fixture to be sealed. You must assess the lengths, diameters, and available space to lock and inspect the seal while considering the environment and duration of use
  • use the seal type with the appropriate level of strength and security for the goods being transported
  • implement a manageable process that aligns with time constraints

As discussed previously, the system should also be within the capability of the facility and the person(s) applying and inspecting the seal. Also, if special tools are required, consider both cost and availability of tools. The information included on the seal could be as little as a sequential number but could also be as extensive as logos, product codes, barcodes, and even complete tracking history and loading data. Sophisticated or complex systems without adequate facilities and staff are not effective and simply complicate and frustrate those operating within the supply chain. Our recommendations when implementing your seal procedures is to:

  • use materials suitable for the environment where the tamper evident seals are to be used.
  • ensure the seal has capacity to contain all of the information needed. 


You can view our 3.5mm Cable Seals here:

You can view our 2.5mm Cable Seals here:

You can view our Metal Bolt Seal here:

If you require a more bespoke option, you can use contact us by sending an enquiry the quote page or alternatively you can call our sales team on 01252624305.


JW Products have been servicing the security seal requirements of the transport, haulage and aviation industry worldwide, for over 20 years. We have built a reputation for reliability, expertise and excellence since our conception in 2000 and we are ready to help your business thrive in a post Brexit world. You can rely on our dedicated team to identify your business’s security seal requirements and offer approved solutions to meet them. We offer high security tamper proof security seals, conforming to ISO 17712:2013 and effective tamper evident seals, to help your business meet regulatory standards and protect your assets. As a trusted supplier to Government Agencies, NHS and UK Police Forces, your business can engage with JW Products with confidence.

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