In the pre-tensioned concrete application, the pre-stressed steel wire is tensioned approx. 70 to 80% of the minimum specified breaking load of steel wire prior to casting of concrete. After initial setting of concrete, the pre-tensioned steel wire is released and the stress in the wire is induced in the concrete. This induced compressive stress will neutralize the tensile stress caused by the acting loads on the concrete member. In the case of pre-tensioning, it is important that adequate bond is created between the steel wire and concrete in order to transfer the desired compressive force from the steel wire to the concrete.

In order to improve the bond strength and achieve a consistently low transmission length, regular indentations of specified shape in the wire surface in either opposite or 120-degree planes or 90-degree planes were introduced. In the known art of indenting operation, it is possible only to make 2, 3 or 4-sided intermittent indentation on the surface of the wire. This indentation is normally carried out on a wire-drawing machine and is effected by pulling the wire through appropriate indenting rolls.

Advantages
- Improves the bond strength between pre-stressed steel wire and concrete
- Reduces the frictional losses between pre-stressed wire and concrete
- Increases the anchorage efficiency
- Maintains higher effective pre-stressing force in the structure
- Reduces the number of operations at the customer end