This vintage farm implement is a cast-iron chain detacher (also known as a roller chain tool or sprocket roller chain tool). It was originally carried on tractors to make chain repairs. While its name hints that its main use was to detach chain links, it can also be used to repair, or reattach, links. The one pictured here is typical of detachers manufactured in the late 1800s and turn of the century. It has 3 notches to accommodate different size links.

Link-Belt Machinery was founded in 1880. The company expanded in 1888, when Link-Belt Engineering was born. The company thrived, and in 1967, it merged with FMC, which is still in existence today.

Thanks again to Barb C. of Versailles, IL, for submitting this month's mystery item!