Prop is a labour and time saving device to support shuttering and centring. It is made out of 60mm O.D. & 48mm O.D. tubes moving in each other telescopically. A heavy duty S.G. iron nut provides fine adjustment of height of prop. Top and bottom plates are provided with nail holes for wooden runner and holes for bolting. While after using props one above other. It is essential to have bracing in two directions just above outer tube for feight beyond 3500mm. Use of props by double staging is recommended upto 7000mm height only. The threads are rolled and not cut threads.