Bolts Are Not Nails: Overcoming Misconceptions about Wedge Bolt Use in Permanent Rigging

Considerable misinformation circulates in mountaineering and cave exploration circles concerning the torque needed to correctly install the wedge anchors used in technical rigging. Misunderstanding the proper operation of wedge bolts has caused serious accidents. This explanation of bolt physics defends the installation of bolts using the torque specifications given by manufacturers and engineering guidelines against the common beliefs of many who install them for climber protection and permanent rigging. KEY WORDS: bolted joint, wedge bolt, permanent rigging, physics, engineering mechanics, shear force