A sikanja is a steel wedge used in formwork for columns and beams to tighten and secure shuttering panels. It is usually tapered so that, when driven into a slot or between panels and supporting elements, it locks the formwork firmly in place. In column and beam shuttering, sikanjas are used to eliminate gaps, hold panels tightly against props or waling, and prevent movement under the pressure of fresh concrete. They ensure that the formwork remains plumb, aligned, and stable, producing clean, accurate edges and corners. Sikanjas are easy to insert and remove, making them reusable for multiple formwork assemblies. They are particularly useful in adjusting panel alignment and taking up small tolerances in shuttering.