Product Selection Guides
Which Seal for Container Transport?
Seal selection for container logistics.
Direct answer
Seal selection for container transport should be based on route, carrier or customer requirements, security classification and the actual locking point on the container door. Bolt/high-security seals are widely used for international ocean freight, but any mandatory standard or class must be verified against the transport contract, country, carrier and customer procedure.
What you will learn
Check route and contractual requirements first; select the product second.
Bolt/high-security seals are common for ocean containers.
Container-door integrity and the correct locking point are as important as the seal.
The serial number should be recorded correctly on transport documents and verified at arrival.
One seal model should not automatically be assumed suitable for every route and customer requirement.
Why selection is not simply 'the strongest seal'
Product strength matters in container transport, but operational suitability is broader. Carrier acceptance rules, customs or transit procedures, customer security policies and cargo risk profiles can differ. Procurement specifications should therefore be derived from the actual route and contractual requirement.
A seal is also only one control point on the container door. If the handle, locking bar or hinge is damaged, even a high-class seal will not deliver the expected security outcome. Pre-sealing inspection is therefore a complementary part of seal selection.
Container-seal selection decision table
| Scenario | Priority | Approach |
|---|---|---|
| International ocean container | Carrier requirement + high security | Verified bolt/high-security seal |
| Domestic short-haul closed equipment | Tamper visibility and speed | Plastic/cable/bolt based on risk analysis |
| High-value cargo | Physical control + strong records | High-security seal + additional oversight |
| Multiple transfers / transit | Chain of custody and serial verification | Unique serial number + check at every handover |
Questions before quotation or purchase
- Which country, port, carrier and route will be used?
- Does the customer or transport contract require a specific security class?
- Are matching serial numbers required on pin and body?
- Are logo, barcode or a custom serial format required?
- Is suitable cutting equipment and safe removal available at the authorized destination?
Container-seal selection process
- 1
Document requirements
Collect carrier, customer and route requirements in one technical list.
- 2
Verify model suitability
Check product dimensions, class, serial structure and test documentation.
- 3
Test a sample on the door
Verify application and removal ergonomics on the actual container locking point.
- 4
Standardize the record procedure
Define who records the number in which document/system and how arrival checks are performed.
Frequently asked questions
Can a plastic seal be used on a container?
It may be physically usable for some low-risk or secondary control points, but international ocean operations may require a high-security bolt seal under carrier/customer rules. Verify the requirement.
Is the most expensive seal the safest choice?
No. Suitability depends on verified security class, door fit, recording system, quality and correct application.
Does using two seals double security?
Not automatically. A second seal may help when it is part of a defined procedure; otherwise it can create record confusion. The official control seal must be clearly identified.
Where should the seal number be recorded?
Depending on the transport model it may be stored in shipping documents, loading records, TMS/WMS or a customer portal. The key is a unique match between physical seal and record.
Is checking only the serial number at arrival enough?
No. In addition to number matching, inspect the body, pin, door handle and locking point for signs of tampering.
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Open quote formThis content is prepared using Senkron Seals product and field experience.