Chain in the context of Torus

A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft.

A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain.

A crane is a machine used to move materials both vertically and horizontally, utilizing a system of a boom, hoist, wire ropes or chains, and sheaves for lifting and relocating heavy objects within the swing of its boom. The device uses one or more simple machines, such as the lever and pulley, to create mechanical advantage to do its work. Cranes are commonly employed in transportation for the loading and unloading of freight, in construction for the movement of materials, and in manufacturing for the assembling of heavy equipment.

The first known crane machine was the shaduf, a water-lifting device that was invented in ancient Mesopotamia (modern Iraq) and then appeared in ancient Egyptian technology. Construction cranes later appeared in ancient Greece, where they were powered by men or animals (such as donkeys), and used for the construction of buildings. Larger cranes were later developed in the Roman Empire, employing the use of human treadwheels, permitting the lifting of heavier weights. In the High Middle Ages, harbour cranes were introduced to load and unload ships and assist with their construction—some were built into stone towers for extra strength and stability. The earliest cranes were constructed from wood, but cast iron, iron and steel took over with the coming of the Industrial Revolution.

In artillery, chain shot is a type of cannon projectile formed of two sub-calibre balls, or half-balls, chained together. Bar shot is similar, but joined by a solid bar. They were used in the age of sailing ships and black powder cannon to shoot masts, or to cut the shrouds and any other rigging of a target ship.

When fired, after leaving the muzzle, the shot's components tumble in the air, and the connecting chain fully extends. In past use, as much as 1.8 m (6 ft) of chain would sweep through the target. However, the tumbling made both bar and chain shot less accurate, so they were used at shorter ranges.

A flatcar (US) (also flat car, or flatbed) is a piece of rolling stock that consists of an open, flat deck mounted on trucks (US) or bogies (UK) at each end. Occasionally, flat cars designed to carry extra heavy or extra large loads are mounted on a pair (or rarely, more) of bogies under each end. The deck of the car can be wood or steel, and the sides of the deck can include pockets for stakes or tie-down points to secure loads. Flatcars designed for carrying machinery have sliding chain assemblies recessed in the deck.

Flatcars are used for loads that are too large or cumbersome to load in enclosed cars such as boxcars, but which will not be harmed by the weather. They are also often used to transport intermodal containers (shipping containers) or trailers as part of intermodal freight transport shipping.

Jewellery chains, jewelry chains or body chains are metal chains that are used in jewellery to encircle parts of the body, namely the neck, wrists and ankles, and they also serve as points to hang decorative charms and pendants.

A chainsaw (or chain saw) is a portable handheld power saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar.

Modern chainsaws are typically gasoline or electric and are used in activities such as tree felling, limbing, bucking, pruning, cutting firebreaks in wildland fire suppression, harvesting of firewood, for use in chainsaw art and chainsaw mills, for cutting concrete, and cutting ice. Precursors to modern chainsaws were first used in surgery, with patents for wood chainsaws beginning in the late 19th century.

In sailing, a sheet is a line (rope, cable or chain) used to control the movable corner(s) (clews) of a sail.

A collar, also known as collar of an order, is an ornate chain, often made of gold and enamel, and set with precious stones, which is worn about the neck as a symbol of membership in various chivalric orders. It is a particular form of the livery collar, the grandest form of the widespread phenomenon of livery in the Middle Ages and Early Modern Period. Orders which have several grades often reserve the collar for the highest grade (usually called the Grand Cross). The links of the chain are usually composed of symbols of the order, and the badge (also called "decoration", "cross" or "jewel") of the order normally hangs down in front. Sometimes the badge is referred to by what is depicted on it; for instance, the badge that hangs from the chain of the Order of the Garter is referred to as "the George".

A hook is a tool consisting of a length of material, typically metal, that contains a portion that is curved/bent back or has a deeply grooved indentation, which serves to grab, latch or in any way attach itself onto another object. The hook's design allows traction forces to be relayed through the curved/indented portion to and from the proximal end of the hook, which is either a straight shaft (known as the hook's shank) or a ring (sometimes called the hook's "eye") for attachment to a thread, rope or chain, providing a reversible attachment between two objects.

In many cases, the distal end of the hook is sharply pointed to enable penetration into the target material, providing a firmer anchorage. Some hooks, particularly fish hooks, also have a barb, a backwards-pointed projection near the pointed end that functions as a secondary "mini-hook" to catch and trap surrounding material, ensuring that the hook point cannot be easily pulled back out once embedded in the target.

Padlocks are portable locks with a shackle that may be passed through an opening (such as a chain link, or hasp staple) to prevent use, theft, vandalism or harm.

A cable railway is a railway that uses a cable, rope or chain to haul trains. It is a type of cable transportation.

The most common use for a cable railway is to move vehicles on a steeply graded line that is too steep for conventional locomotives – this is often called an incline or inclined plane, or, in New Zealand, a jigline, or jig line. A common form of incline is the funicular – an isolated passenger railway where the cars are permanently attached to the cable. In other forms, the cars attach and detach to the cable at the ends of the cable railway. Some cable railways are not steeply graded – these are often used in quarries to move large numbers of wagons between the quarry to the processing plant.

In mechanical engineering, a kinematic chain is an assembly of rigid bodies connected by joints to provide constrained motion that is the mathematical model for a mechanical system. As the word chain suggests, the rigid bodies, or links, are constrained by their connections to other links. An example is the simple open chain formed by links connected in series, like the usual chain, which is the kinematic model for a typical robot manipulator.

Mathematical models of the connections, or joints, between two links are termed kinematic pairs. Kinematic pairs model the hinged and sliding joints fundamental to robotics, often called lower pairs and the surface contact joints critical to cams and gearing, called higher pairs. These joints are generally modeled as holonomic constraints. A kinematic diagram is a schematic of the mechanical system that shows the kinematic chain.

A pocket watch is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist.

They were the most common type of watch from their development in the 16th century until wristwatches became popular after World War I during which a transitional design, trench watches, were used by the military. Watches were also mounted on a short leather strap or fob, when a long chain would have been cumbersome or likely to catch on things. This fob could also provide a protective flap over their face and crystal. Women's watches were normally of this form, with a watch fob that was more decorative than protective. Pocket watches generally have an attached chain to allow them to be secured to a waistcoat, lapel, or belt loop, and to prevent them from being dropped.

Chain stitch is a sewing and embroidery technique in which a series of looped stitches form a chain-like pattern. Chain stitch is an ancient craft – examples of surviving Chinese chain stitch embroidery worked in silk thread have been dated to the Warring States period (5th – 3rd century BC). Handmade chain stitch embroidery does not require that the needle pass through more than one layer of fabric. For this reason the stitch is an effective surface embellishment near seams on finished fabric. Because chain stitches can form flowing, curved lines, they are used in many surface embroidery styles that mimic "drawing" in thread.

Chain stitches are also used in making tambour lace, needlelace, macramé and crochet.

A cable ferry (including the types chain ferry, rope ferry, swing ferry, floating bridge, or punt) is a ferry that is guided (and in many cases propelled) across a river or large body of water by cables connected to both shores. The earliest examples date from the 13th century, and often used either rope or steel chains. These were largely replaced by wire cable by the late 19th century. Cable ferries use relatively little energy, but can hinder other craft.