Can anyone tell me why they make ice screws without extending the thread along the entire length of the screw? It must be fairly common for screws to punch through into air pockets and through curtains. If the screw is long, say 16 cm, and the curtain is 10 cm, and the thread are on the last 10 cm, you might have only 4 cm of threads in ice. The preferred solution would be to remove the long screw and replace it with a shorter one, but it would be entirely unnecessary if the threads went all the way to the head.