1. Chains include four main series: drive chains; conveyor chains; traction chains; and special-purpose chains.
2. A series of chain links or rings, usually made of metal: chain-like structures used to obstruct traffic (such as in streets, river or harbor entrances); chains used for mechanical transmission.
3. Chains can be divided into short-pitch precision roller chains; short-pitch precision roller chains; heavy-duty transmission bent-plate roller chains; chains for cement machinery; plate chains; and high-strength chains.
