A yieldable prop having a hollow first conduit having a first end and an opposite second end, the first end having a conical-shaped interior surface, with interior diameter decreasing as distance from the second end of the first conduit decreases; a second conduit slidably mounted in the first end of the hollow first conduit; and at least two discrete engaging members in the first end of the hollow conduit, each of the at least two engaging members engaging the conical-shaped interior surface and outer surface of the second conduit to prevent the second conduit from sliding into the hollow first conduit, while providing for movement of the first and second conduits away from one another.