Snow chains, or tire chains, are devices fitted to the tires of vehicles to provide increased traction when driving through snow and ice.
Link-type, diamond pattern snow chains on a front-wheel drive automobile.
Snow chains at the front wheel of a grader at the Pikes Peak Highway.
Automatic tire chains are permanently mounted near the drive tires and engage by turning a switch, then move into position to fling the pieces of chain under the tires automatically. Automatic chains were invented in 1941 in the United States and Sweden in 1977[citation needed].
Cable chains on a car tire, with a relatively simple and easy-to-secure design; this is a ladder-type or "radial" design
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use:Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are torus shaped, which make the chain flexible in two dimensions. Small chains serving as jewellery are a mostly decorative analogue of such types.
Those designed for transferring power in machines have links designed to mesh with the teeth of the sprockets of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chains.
A common metal short-link chain
Roller chains
Links of the American Revolutionary War-era Hudson River Chain as a memorial at West Point
Prisoner in belly chain