Hi Hasse, Your question is a little condition dependent. If the thread is drilled properly then it will be safe, your problem may come when you try to remove the rope. The movement of the rope can melt the ice which can subsequently re-freeze making it extremely difficult to remove the rope. This page/video might be of some help: http://www.petzl.com/EN/Sport/Video--The-basics-of-ice-climbing--ice-screw-placement--belays--v-threads?ProductName=LASER-SPEED#.VdW8S_lViko Hope that helps, Dave