A chain is usually made of metal (steel, such as stainless steel is most commonly used) and is a series of joined or connected links. Chain can be made in many different styles and these have a number of important and decorative applications. Metal chains have been used for many thousands of years and is commonly listed as being invented around 225 BC, although many historians think this could have happened much earlier. Today, you will find them being used for many different purposes. Small delicate chains are often used as jewelery and the largest chains are designed for heavy lifting or for use in large industrial machines. Let’s find out how chains are made.
How is chain made?
Chain begins life in the factory as large rolls of wire, which are placed on a spindle and stretched through a device that lubricates, narrows, hardens and strengthens the wire. The wire is then wound on a large drum and it is ready for creating the chain. The next step in the process depends on the type of chain being made, but in general strong machines bend the wire, and then cut it, to form the links in the chain. Some chains are made by wire that is cut into smaller lengths and these are again bent by larger machine. These links may have small gaps, which are welded together with a special machine. Each factory has many different types of forming machine and they all create different types of chain.
The final stages of the manufacturing process is heat treating. The chain is passed through a heat treating coil, which uses an electrical current to heat the chain until it is glowing hot. The chain is then dipped into water to cool. This process makes the steel harder, but it also created a brittle steel. To prevent this from being a problem the chain is again run through a heat coil, which is not as hot as the first, and it is again dipped into cool water. The chain is then tested with a special machine and when is passes these tests it is ready for shipping.
The following video shows different types of chains being made in a large factory.