Introduction: Removing a metal seal closes out the sealed transport state and ties the opening moment to a numbered physical seal, a visible mark, and the handover record.
A mechanical seal belongs to the transport control chain rather than standing apart from it. In container operations, that chain begins with closure, continues through handover and movement, and ends when an authorized cut opens the unit. The MS-B metal band seal with ball fits that pattern clearly: the band is bent into a ball-lock closure, the surface carries `SEALED` and a unique number, and the removal step uses a cutting tool rather than hand force. That sequence gives the seal its practical value. The closure shows that the unit was sealed, and the cut shows when that sealed state ended.
A seal only has meaning while it is attached to the transport unit. The CTU Code places the emphasis on correct packing, correct closure, and correct handover of cargo transport units, so the seal sits inside the closing and release process instead of replacing it. That is why tool removal matters. When a metal band seal is cut, the physical state changes in a way that can be seen immediately. The loop is no longer intact, the lock is no longer holding the band in the same closed position, and the unit has moved from sealed to opened. That visible change is especially clear on an MS-B style seal. The product is described as a tinned steel metal band seal with ball closure, and the listing says it cannot be removed by hand. Steel wire cutters are the tool type named for this job. The tool does not create the seal; it ends the sealing stage in a controlled, visible way. That is why the number and the `SEALED` marking still matter at the moment of opening. They identify which seal was on which unit before the cut, so the open state can still be traced back to the closed state. The practical reading is straightforward: the seal marks closure, and the cut marks release. That is the point where a transport unit leaves its sealed state and enters the next handover stage.
The first useful step is to record the seal number, the `SEALED` marking, and the visible condition while the seal is still intact. That keeps the seal identity separate from the container identity. A container number identifies the transport unit, while the seal number identifies the seal attached to it. BIC container identification standards are useful here because they reinforce that container identity and seal identity are different pieces of information. When both are written down before opening, the record can show exactly what was in place at the handover point.
An authorized removal belongs at an agreed handover point such as arrival, inspection, release, or another controlled transfer. The reason for cutting matters as much as the tool itself. In a controlled operation, the seal is removed because the transport stage has ended, not because the opening needs to be hidden. The visible cut then matches the release event, and the record can reflect that the unit moved from closed to open in the expected sequence. After the cut, the note should keep the seal number, the opening time, and the observed condition together so the opening history remains easy to follow later. That record can also include the removed seal if local practice keeps it with the file. The value is not paperwork for its own sake. It is the link between what was seen, what was cut, and when the open state began. A clean record makes later checks easier because the opening event remains readable after the unit has moved on.
A normal opening and an abnormal opening can both leave the seal off the container, but they tell different stories. Under the broader cargo control approach used by the UNODC-WCO Container Control Programme, the seal is one part of a wider control system. That wider system includes the unit itself, the seal number, the visible condition, the route, and the handover record. When those elements line up, the opening reads as a routine release at the expected point in the process. An abnormal opening has a different pattern. A missing seal, a broken seal found earlier than expected, or a seal number that does not match the record shifts the reading. Those signs point to an exception that needs to be handled under the applicable process. The seal still gives the operation a visible reference point, but the reference now points to a mismatch rather than a normal release. That is why the same physical object can support two different readings: one confirms that the sealed state ended on time, while the other shows that the record and the observation need closer review. The key distinction is between an opening event and an opening explanation. The cut alone only says the seal is no longer in place. The number, the marking, and the handover note explain whether the opening belongs to the expected transport flow or to an exception that needs follow-up.
Tool removal is part of the sealing process because it ends the closed transport state in a visible, traceable way. On an MS-B metal band seal with ball, the cut connects the physical seal to the shipment record, and the `SEALED` mark plus unique number help preserve that connection after opening. The most useful reading is not only how the seal closes, but how clearly the opening can be traced later. When the seal model, the numbering rule, or the handover record needs confirmation, the MS-B listing is the natural place to review the closure method and request matching details for the operation.
A：Steel wire cutters are the tool type described for this kind of seal, and similar cutting pliers can serve the same basic purpose when they can sever the metal band cleanly. For the MS-B example, the band is cut, the ball-lock loop is released, and the seal moves from a closed state to an opened state.
A：It should be recorded before the seal is cut and before the container is opened. That is the moment when the number, the `SEALED` marking, and the visible condition still match the transport unit in place. Capturing it at that point keeps the seal identity tied to the handover record.
A：Cutting it creates a visible opening trace that stays useful for later review. The unique number, the `SEALED` marking, and the handover record keep the opening history readable after the cut, so the seal remains an identity and traceability marker inside the transport record.
Code of Practice for Packing of Cargo Transport Units (CTU Code)
The UNODC-WCO Container Control Programme
