As traction means the transfer of "force" from one point to another.
Are usually used for robust efforts, with frequent loads to tearing for suspended loads of large dimensions. therefore must meet strict rules of resistance and "security", as required by specific regulations.
Long duration in chains is guaranteed by materials used for pins like high strength cements "alloy pins" to obtain a tenacious core resistance to wear and tear. Chains are used for drawing machines and galls for their higher effots but horizontally.
The chains for drawing and galls are used for the higher efforts but horizontally. Details...