In building my RV-6A, I am always surprised by the number of sheet metal aircraft builders who come by to visit my project and have overlooked the utility of using NAS1097 rivets in a wide range of applications. Sometimes, these fasteners are inadvertently trivialized by being referred to as "oops" rivets. They are much more than that. Most aluminum homebuilt designs make great use of .032 and thinner material. Countersinking such thin material for an NAS426 rivet virtually guarantees generating a knife edge, or worse, a wallowed out hole....not a good thing. The NAS1097 rivet has a much smaller manufactured head, and in many cases, you can generate a sufficient countersink by simply placing a large diameter drill bit onto the surface of the material and rolling it through your fingers until an adequate countersink depth is achieved! NAS1097 rivets are ideal for attaching nutplates, installing doublers and many other applications. Available in almost as many diameters and lengths as NAS427 rivets, I have found the NAS1097-3-3.5 to be the most frequently used.