Helical Spring
Helical Spring : (Mech Eng) Round, square, or rectangular wire, wound in the form of a helix, offering a resistance to a force applied along the axis of the coils. Note: When wound with space between coils, the spring may be loaded in compression. When the force is applied to stretch the coils, it is termed a helical tension spring. When force is applied in a twisting direction in the plane of the coils, it is called a helical torsion spring.