TWI Industrial Member Report Summary 492/1994
S A Westgate and M C Whittaker
The self piercing riveting and press joining techniques covered in this report are relatively new mechanical fastening systems which can provide fag economical joining methods for sheet materials. The assembly speed, case of automation and environmental advantages have been exploited in applications, particularly in the automotive, domestic appliance and heating and ventilation industries, to replace spot welding or more traditional fastening methods. Suitable materials include coated and pre-painted steels and aluminium alloys. The applications experience and joint property data are available principally from the suppliers of the proprietary systems. Increasing interest in these methods has highlighted the need for work to provide increased confidence in joint properties, process tolerance and reliability, particularly for more demanding automotive applications. This current programme represents the first major study of mechanical fastener systems for TWI, as part of its sheet joining activity, and includes a summary of features and advantages of the various joining techniques.
A comparison is made of commercial press joining and self piercing riveting systems, evaluating the features and static peel and shear properties of single joints. A range of materials was used, including steels, an aluminium alloy and aluminium/polypropylene/aluminium sandwich material. The mechanically fastened joints were assembled by the equipment suppliers and evaluated at TWI.