How Lead Seal Secure Cargo, Shipments, and Valuable Items

A lead seal is a type of seal made from lead, functioning like a lock. Its purpose is to protect important items and prevent unauthorized access or tampering. Lead Seals are actually quite common in our daily lives, though many people may not notice them—for example, every household electricity meter is fitted with a lead seal to prevent tampering without permission.

Lead seals are also referred to as “sealing tags.” For instance, in ancient times, items under official inspection had to bear an official seal, which served the same purpose. Over time, sealing methods have evolved, with materials ranging from lead and iron to plastic and electronic seals. Modern seals are increasingly environmentally friendly and safer.

Each lead seal carries a unique identification number, called a seal code. This code is guaranteed not to be duplicated within a short period. In international shipping, to ensure that containers are not opened arbitrarily, carriers record the seal code when releasing a container. This code also appears on the delivery order. Customers can verify whether the seal has been tampered with by checking the code. In some cases, a seal applied at the factory may be replaced at a port inspection during customs checks. The new seal code is then recorded on the delivery order. By comparing the recorded code with the physical seal, it is possible to determine whether the container has been opened, ensuring that only authorized personnel can remove the seal, thereby preventing cargo from being swapped during transit.

Zhengcheng Lead Seal is a professional lead seal manufacturer with over 20 years of experience. The company has become an innovative high-tech enterprise integrating electronic seals, RFID smart seals, IoT solutions, and various lead seal production and sales. Zhengcheng operates 69 production lines, including injection molding, painting, laser marking, product assembly, automated production lines, and mold manufacturing. Among them, there are 35 injection machines, including five 1000-ton machines and 18 machines of 500–600 tons. Its single lead seal production line has an annual output of tens of billions of pieces.