Unbonded post tensioning is a method of reinforcing concrete with tendons made of high-strength steel strands. Pre-stressing steel is attached to the concrete at the anchorages in an unbonded tendon. Monostrand (single-strand) tendons are the most popular unbonded systems and are utilised in slabs and beams for buildings, parking garages, and slabs on the ground.

A monostrand tendon is made up of a 7-wire strand that has been coated with corrosion-inhibiting grease and is protected by an extruded plastic sheathing. An iron casting and a conical, two-piece wedge that grasps the strand constitute the anchorage.