Security Seals Guide
What is a Bolt Seal?
Structure of bolt seals and container applications.
Direct answer
A bolt seal is a single-use, high-strength security seal made of a metal pin and locking body, used primarily on ocean-container doors. The correct model is selected not simply because it looks thick or strong, but by considering the required security class, closure point, serial numbering, test documentation and controlled removal procedure together.
What you will learn
A bolt seal closes the container locking point with a single-use physical identity.
Matching serial numbers on pin and body make operational verification easier.
A high-security claim should be verified through relevant test and conformity documentation, not appearance.
A strong product alone is not enough if the seal is applied to the wrong door or closure point.
Removal requires a suitable bolt cutter, safe working practice and an authorized opening procedure.
How does a bolt seal work?
A bolt seal has two main components: a metal pin and a body that locks the pin in one direction. The pin is passed through the correct locking hole on the container door and fully seated in the body. Once the lock engages, the seal cannot be reopened in normal use; controlled removal is performed with cutting equipment.
In many professional applications, the pin and locking body carry the same serial number. This makes it possible to verify that both parts belong to the same seal set. The feature simplifies comparison between the physical seal and documentation at loading, customs, port and delivery points.
Technical checks when selecting a bolt seal
| Criterion | Why it matters | Check |
|---|---|---|
| Security class | May be required by transport or customer specifications | Current test/conformity documentation |
| Pin diameter and geometry | Physical fit with container locking point | Actual door or measured sample |
| Serial numbering | Unique linkage to a shipment | Pin-body matching and duplicate control |
| Marking | Operational and customer identification | Readability of logo, barcode and text area |
| Packaging | Management of serial ranges in the field | Pack/carton sequence and number control |
| Removal equipment | Safe and controlled opening | Suitable bolt cutter at the authorized point |
Where are bolt seals most commonly used?
- Ocean containers and intermodal transport
- Import, export and transit cargo operations
- Projects and tenders requiring high-security closure
- Containers tracked by unique serial number throughout shipment
Correct field application of a bolt seal
- 1
Inspect the door and locking point
Verify that locking bars, handle and seal hole are free from damage or looseness.
- 2
Record the serial number
Linking the number to the shipment record before application reduces transcription and substitution errors.
- 3
Fully engage the pin
Pass the pin through the correct point, fully seat it in the body and confirm engagement with a light pull check.
- 4
Check number and integrity together at arrival
Check not only the correct serial number but also physical signs on the pin, body and closure point.
Frequently asked questions
Is a bolt seal the same as a container seal?
A bolt seal is one of the most common high-strength types of container seal. 'Container seal' is a broader usage term, while bolt seal describes a specific product architecture.
Is every bolt seal a high-security seal?
No. Being shaped like a bolt seal does not by itself prove a specific security classification. Model-specific test and conformity documentation should be checked for the required class.
Can a bolt seal be reused?
No. It is single-use by design, and a new uniquely numbered seal is required after controlled removal.
Should the serial number appear on both parts?
Requirements vary, but matching numbers on pin and body provide stronger operational verification against component substitution.
How is a bolt seal removed?
At an authorized destination it is removed using a suitable bolt cutter while following safe cutting practices, including eye/face protection and controlled cutting direction.
Related products
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