What is a chain?
A chain is a sequential gathering of connected pieces, called links, generally made of metal, with a general trademark like a rope. A chain may comprise at least two links. Chains were first used in 225 BC.

Uses of chains
A chain is used for decoration, security and restraint purposes, power transfer, traction pulling, hoisting, hauling and making of weapons. Chains are used in keychains, cycles, embroidery machines and as percussion instruments for special effects.

Types of chains
The 5 main types of chains include:
Flat chains: These are used in agricultural machinery.
Ladder chains: These are light wired chains used for power transmission.
O-ring chains: These are specialized types of roller chains.
Roller chains: These chains are mainly used in automobiles like bicycles and motorcycles.
Silent chains: These types of chains engage with sprockets that are similar to gear teeth.

Compositions of chains
Chains can be made of any metal, depending on their use.
Common Industry uses:
Agriculture: Chains are used in hand pumps and ploughs.
Manufacturing: Chains are used in conveyor belts and rotating and grinding machines.
Fashion: Jewellery includes all sorts of chains as bracelets and necklaces.
Household: This includes door chains and locks.