in the shape of a coil

A tightly-coiled, elongated wire used in the manufacture of innerspring units to join individual coils to each other and to the border rod.

A small helix or spiral shaped wire that is used to connect coils.

Having the shape of a helix or spiral; screw-shaped.

It means a spiral, and is a term referring to the type of torsion spring used in the spring counterbalance.

Springs of spiral or cylindrical shape such as compression, extension or torsion springs.

Having the form of a spiral.