Acme Screw Thread Profile by Wizard191 CC-BY-SA 3.0 Screw thread profiles can be modified from the standard V profile for better performance under different loads. The Acme profile, a trapezoidal ...

The video by Petzl that demonstrates proper ice screw placement technique, as well as how to set an anchor and a v-thread in waterfall ice. It's clear seven minutes don't suffice to cover all ice ...