Finished Lego elements wait to go into packages in a storage facility in Billund, Denmark. Image courtesy ©Lego

If you've bought a Lego set -- whether it's a box of assorted bricks or a set meant for building something specific -- you've probably noticed that the box includes several bags of bricks rather than a large pile of loose elements. These bags are part of the automated packaging process, and they help make sure that the right pieces go into each box.

" " Quality assurance testing ensures that Lego parts are durable and will stand up to lots of play. Image courtesy ©Lego

During the packaging process, bins open and close automatically, dropping precise numbers of bricks into each polypropylene bag. A machine weighs these bags to make sure their contents are correct. If a specific bag's weight is incorrect, an operator can replace that bag, rather than having to discard an entire set.



" " LEGO testing and packaging involves drop, torque, tension, compression, bite and impact tests. Read more about how LEGO toys are tested and packaged. HowStuffWorks

At the end of the process, packaging operators fold the boxes, add any necessary pieces and make sure that the machines haven't made any mistakes. The sealed boxes are stored and shipped around the world -- the process uses between 400,000 and 500,000 cardboard boxes per year.

Quality assurance testers also perform numerous inspections and tests on Lego elements. Machines perform drop, torque, tension, compression, bite and impact tests to make sure the toys are sturdy and safe. Technicians use a measuring beaker to determine whether pieces could cause a choking hazard for small children. For every million Lego elements, about eighteen, or 0.00002 percent, fail to pass the tests.

Much of the manufacturing process takes place in Klando, Czech Republic and Billund, Denmark. All in all, Lego factories produce 33,000 bricks every minute, for a total of 16 billion bricks every year. The manufacturing facilities can make 3,000 different types of elements, including 300 million tires, and these pieces go into 37,000 Lego sets every hour.

In the next section, we'll look at what you can do with all those finished bricks.­