For this reason, spin riveting is particularly useful for assemblies where a pivot is required, such as scissors, pliers or hinges. Importantly, modern real-time process controllers enable the forming to be closely controlled so that, for example, the rivet head can be formed to a desired height, or the rivet can exert a specified load on the finished joint. For example, heads can be flat, conical, crowned, shouldered or flared into countersunk holes. This gradually forms the rivet head into the desired shape, the actual geometry of which depends on the rivet, peen and process parameters. The tool then rotates around the vertical axis, while also applying an axial load. Instead of the single axial stroke that is used in impact riveting, the forming tool (also referred to as a peen) contacts the rivet head at an angle of three to six degrees from the vertical. Spin riveting is, in comparison with impact riveting, a closely controlled process whereby two or more components are joined using one or more separate hollow or solid rivets. However, there are some related processes, namely spin riveting, orbital riveting and orbital forming, that are experiencing a resurgence in interest, partly as a result of recent developments in real-time process control technology. While this is partly true, impact riveting remains the optimum fastening method for many applications, such as leatherwork, tools, toys, kitchen utensils or general hardware, where the speed of the process is attractive and there is no justification for a high degree of control over the process or a need for particularly tight tolerances.īecause of the nature of the process, it is fair to say that there has been relatively little research and development in the field of impact riveting over the past 40 years. Impact riveting, where a solid or hollow rivet is formed with a single blow, is one of the oldest imaginable joining methods and, therefore, is often considered to be ‘low technology’ and only suitable for low-value, high volume assemblies or those where tolerances are not particularly tight.
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