Let me preface this by saying that I'm not an ice climber...
Question of the day: while reading the newest glossy, i glanced at an article on ice screw placement by Craig Leubben (sp?)...anyway, he says the best placement for a screw is at 15-20 degrees angling upwards!?! Why is that? My guess is to minimize a "prying" effect on the lip of the hole by the shaft of the screw...in effect, turning it into a tension only placement as opposed to a combined tension and shear problem. Is this right? Does anyone know?