The course external thread of SPIROL's Self-Tapping Insert forms an internal thread within a moulded or pre-drilled hole during the installation process into a plastic assembly. SPIROL Series 10 Self-Tapping Inserts are thread forming Inserts best suited for softer thermoplastics or thermosets.
Self-Tapping Inserts provide the best pull-out resistance for a post-mould installed Insert, yet generally cost more than their post-mould counterparts. The external threads are designed with a thin profile to minimise induced stress in the plastic and have a relative coarse pitch to provide the maximum plastic shear surface to resist pull-out.
Installation torque is not a problem in that tightening increases the friction between the plastic and threads, and the larger diameter of the external Insert thread increases the frictional surface. Back-out torque performance relies totally on the greater surface area of the external Insert thread and the tension between the threads and plastic.
If installation equipment is required, SPIROL also offers a comprehensive line of Insert Installation Equipment from manual to fully automatic modules, with or without out fixturing, to support your Threaded Insert assembly requirements.