Tensile stress (or tension) is the stress state leading to expansion (volume and/or length of a material tends to increase). In the uniaxial manner of tension, tensile stress is induced by pulling forces across a bar, specimen etc. Tensile stress is the opposite of compressive stress.
Structural members in direct tension are ropes, soil anchors and nails, bolts, etc. Beams subjected to bending moments may include tensile stress as well as compressive stress and/or shear stress.
Tensile stress may be increased until the reach of tensile strength, namely the limit state of stress.
See also: tension, shear stress, physics, tensile strength, strength of materials, Hooke's law.