![]() However, without the need for a rivet, the scope of the process is dramatically increased. In such applications, the term orbital riveting is often used instead of spin riveting.Įssentially the same process, orbital riveting also uses an offset peen to gradually form the material into a head that holds the assembly together. Moreover, where volumes are high enough, it is likely to be more cost-effective to design-in a joining element on one of the components in the assembly, rather than using a discrete rivet. In some applications it is desirable to avoid using a separate rivet – perhaps in order to keep the parts count down, or to avoid the risk of intermetallic corrosion. However, these are primarily limited to the cost of the equipment and the cycle time (typically 2 to 15 seconds). Of course, spin riveting has its drawbacks compared with impact riveting. Spin riveting is commonly used in applications as diverse as low-volume aerospace assemblies and high-volume automotive components. Part of the reason for this is that the process is performed cold, which keeps the equipment comparatively simple, and the tooling is low-cost and long-lasting. For that reason, quieter joining processes are more attractive than ever before.ĭespite the relatively tight tolerances and excellent consistency that can be achieved on the height and joint load, spin riveting remains very economical, even for small volumes. EU Member States have until 6 April 2006 to transpose the Directive into local Regulations, after which employers will be obliged to meet the tighter requirements. The Directive tightens the legal requirements in relation to noise by lowering the exposure action values to 80 and 85dB(A). EU Directive 2003/10/EC on the minimum health and safety requirements regarding exposure of workers to the risks arising from physical agents (noise), which will repeal Directive 86/188/EEC, was adopted on 9 December 2002 and came into force on 15th February 2003. Consequently such processes are popular for safety-critical assemblies and those where vibration or thermal cycling might otherwise cause problems (Fig.1).Īnother factor that should be taken into account is the noise spin riveting is significantly quieter than impact riveting. One of the advantages of spin riveting – and orbital riveting and orbital forming – is that the resultant joint is far more resistant to vibration than if threaded fasteners are used. If the rivet passes through, say, a polymer or soft metallic component, a load-spreading washer can be used beneath the head of the rivet – which might also be shouldered. Compared with impact riveting, there is no risk of unwanted damage to the parent material, and the gradual forming process does not crack or otherwise damage the rivet. 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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