Expansion & Self-Threading Installation
Dodge offers a range of simple tooling for expansion and self-threading inserts. These hand and semi-automatic tools can be fitted to manual or powered presses. For more information see the tooling description under the respective insert types.
Inserts may be installed into thermoplastic materials using various sources of electrically generated energy to heat the insert above the melting point of the thermoplastic part. Inserts may be preheated then pressed into the plastic part, or the insert may be piloted into a cored or drilled hole in the plastic part then heated by conduction.
Heated insert installation provides a stress-free assembly and is recommended for very large insert sizes or when the required fixturing or noise levels associated with ultrasonic installation are prohibitive.
Ultrasonic installation is recommended for all but the largest insert sizes. Ultrasonic installation generally results in very consistent, stress-free assemblies with very short cycle times. In ultrasonic insertion, the metal insert is designed to partially enter a cored or drilled hole in the thermoplastic part. The vibrating ultrasonic horn contacts the insert causing vibration to travel through to the interface of the metal insert and the plastic part. Heat generated as a result of the vibration causes the plastic to effectively mold itself to the knurl and undercuts of the insert, permanently locking the insert in place.
Dodge's Applications Engineering Team is available to assist in recommending installation and assembly systems as well as custom fixturing for your application.