![]() Does not require a pre-drilled hole (A).Mandrel component can be of permanent or break-off design.Threaded mandrel component integrated into rivet.Only requires access to one side of a joint (A).Tubular design with a mandrel running through the center.Notes: If applicable, “A” indicates advantageous characteristics and “D” indicates disadvantageous characteristics. ![]() Table 1 – Characteristics of Rivets by Type However, unlike the latter design, speed fasteners incorporate the mandrel component into the rivet setting equipment rather than as a separate break-off component of the rivet, which can significantly increase the speed of installation in comparison to that of the previously mentioned designs. Speed fasteners-also referred to as hollow bore or mandrel-loaded rivets-are a type of blind rivet which operates similarly to the standard blind rivet design. With the self-tapping rivet, the hole drilling process is completely removed and instead replaced with a screwing motion that both creates the rivet hole and locks the rivet into place. Essentially, the difference between the rivet designs is the manner in which the hole is punched through the sheet metal. The self-tapping rivet was developed to resolve some of the issues with self-drilling, blind rivets. Additionally, the self-drilling process can be less precise than other insertion processes, resulting in swarf or burrs around the rivets and a decrease in the overall stability of the assembly. The high complexity of the design and high precision required to manufacture the threaded drill raises the cost of the part significantly in comparison to other rivet types. One disadvantage to these types of rivets is their cost. Additionally, the threaded mandrel tip can either remain on the end of the rivet or dislodge once the rivet is fully inserted. As a result of this design feature, the rivet can drill its own hole as the rivet gun drives it in. Self-drilling blind rivets have threaded drill sections on mandrels protruding through hollow cylinders within the rivet. One solution to this issue is the use of a self-drilling blind rivet. This requirement increases the total lead time, especially for large production runs, which can make using rivets less cost-effective than other fasteners. In addition to standard blind rivets, several unique designs are available: Self-Drilling, Blind Rivetsīefore setting most rivets-including the aforementioned standard blind rivet-a riveter must drill holes into the workpiece. Once the blind rivet is inserted, a specialized riveter draws the mandrel back, forcing the inserted end of the rivet to expand (and, in some cases, the mandrel to break off) which fastens the materials together and forms the joint. Using this type of blind rivet requires a pre-drilled hole through the materials being fastened, into which the blind end of the rivet is inserted. The standard blind rivet design features a tubular form with a mandrel running through the center. Unlike normal rivets which require access to both sides of a joint, blind rivets only require access to one side to fasten materials together. Blindīlind rivets, also referred to as POP rivets, are fasteners which enable materials to be joined together when the back side of the joint (i.e., the blind side) has limited access or is entirely inaccessible. This allows the two riveted surfaces to rotate with respect to one another, and so produce a permanent, hinged joint on a stepladder, for instance. It limits the deformation to the tail of the rivet without expanding the shank. The hollow tail serves another purpose, though. These holes permit the rivets to be upset using about a quarter of the force required for deforming solid rivets of like dimensions. ![]() Tubular rivets, sometimes called semi-tubular rivets, are similar to solid rivets except with holes in the centers of their tails. Solid rivets are available in a host of sizes and materials, with SAE 1010 and screw-machine steel being common, and brass, nickel-silver, bronze, copper, stainless steel, and aluminum being popular, as well. ![]() ![]() The other three methods offer significant improvements in the quality of the finished head and its strength. Staking is often done manually with a rivet gun and mandrel, or bucking bar. Four methods are used to clinch the unheaded side, including staking, spin-roller forming, orbital forming, and radial forming, with staking being the fastest and cheapest method but one which leaves the formed head relatively unfinished. They are available as cold- and hot-headed varieties in flat, cone, button, and countersunk head styles. With their full-bodied design, solid rivets represent the strongest of the rivet varieties and, installed red-hot, were the rivets employed in structural-steel buildings and the like before bolted- and welded-joint techniques supplanted them. ![]()
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