Threaded bolt or screw, has right handed thread on its shaft and left handed thread on or inside its head

摘要

#CMT# #/CMT# The fastener shaft has a right-handed thread and the head is provided with an internal or external left-handed thread, preferably combined with a hexagonal hole, slot and/or other geometries in series or parallel. The fastener is tightened or loosened using a tool which has a tip provided with both external and internal left-handed threaded. #CMT#USE : #/CMT# A bolt or screw fastener is described. #CMT#ADVANTAGE : #/CMT# Theft or vandalism caused by unauthorized fastener removal is prevented due to the need for a special tool, since the fastener can not be removed simply by untwisting with a conventional screwdriver or other tool. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure shows the bolt.