The general types of rivets are solid, blind, tubular, and metal piercing (including split rivets). From a structural design aspect the most important rivets are the solid and blind rivets.
Solid Rivets: Most solid rivets are made of aluminum so that the shop head can be cold formed by bucking it with a pneumatic hammer. Thus, solid rivets must have cold-forming capability without cracking. A representative listing of solid rivets is given in table IX (ref. 2). Some other solid rivet materials are brass, SAE 1006 to SAE 1035, 1108 and 1109 steels, A286 stainless steel, and titanium.
Note that the rivets in table IX are covered by military standard specifications, which are readily available. Although most of the solid rivets listed in table IX have universal heads, there are other common head types, as shown in figure 34. However, because the “experts” do not necessarily agree on the names, other names have been added to the figure. Note also that the countersunk head angle can vary from 60° to 120° although 82° and 100° are the common angles.
The sharp edge of the countersunk head is also removed in some cases, as in the Briles BRFZ “fast” rivet (fig. 35), to increase the shear and fatigue strength while still maintaining a flush fit.
Blind Rivets: Blind rivets get their name from the fact that they can be completely installed from one side. They have the following significant advantages over solid rivets:
- Only one operator is required for installation.
- The installation tool is portable (comparable to an electric drill in size).
- They can be used where only one side of the workpiece is accessible.
- A given-length rivet can be used for a range of material thicknesses.
- Installation time is faster than with solid rivets.
- Clamping force is more uniform than with solid rivets.
- Less training is required for the operator.
Blind rivets are classified according to the methods used to install them:
- Pull mandrel
- Threaded stem
- Drive pin
Pull-Mandrel Rivets: This rivet is installed with a tool that applies force to the rivet head while pulling a prenotched serrated mandrel through to expand the far side of the tubular rivet. When the proper load is reached, the mandrel breaks at the notch. A generic pull-mandrel rivet is shown in figure 36.
Threaded-Stem Rivets: The threaded-stem rivet (fig. 37(a)) has a threaded internal mandrel (stem) with the external portion machined flat on two sides for the tool to grip and rotate. The head is normally hexagonal to prevent rotation of the tubular body while the mandrel is being torqued and broken off.
Drive-Pin Rivets: This rivet has a drive pin that spreads the far side of the rivet to form a head, as shown in figure 38. Although drive-pin rivets can be installed quickly, they are usually not used in aerospace applications. They are used primarily for commercial sheet metal applications.
Tubular Rivets: Tubular rivets are partially hollow and come in a variety of configurations. The generic form has a manufactured head on one side and a hollow end that sticks through the pieces being joined. The hollow end is cold formed to a field head.
Since extensive cold forming is required on these rivets, they must be extremely ductile and are consequently made of low strength materials. They are normally used for commercial applications rather than in the aerospace industry.
Some specific types of tubular rivets are
- Full tubular
Compression Tubular Rivets: A compression tubular rivet (fig. 39) consists of two parts that have an interference fit when driven together. These rivets are used commercially in soft materials and where a good appearance is required on both sides of the part.
Semitubular Rivets: The semitubular rivet (fig. 40) has a hole in the field end (hole depth to 1.12 of shank diameter) such that the rivet approaches a solid rivet when the field head is formed.
Full Tubular Rivets: The full tubular rivet (fig. 41) has a deeper hole than the semitubular rivet. It is a weaker rivet than the semitubular rivet, but it can pierce softer materials such as plastic or fabric.
Metal-Piercing Rivets: Metal piercing rivets (fig. 42) are similar to semitubular rivets, except that they have greater column strength. Part of the sandwich material is not drilled, and the rivet pierces all the way or most of the way through while mushrooming out to a locked position.
Split Rivets: Split (bifurcated) rivets (fig. 43) are the standard “home repair” rivets. They have sawed or split bodies with sharp ends to make their own holes through leather, fiber, plastic, or soft metals. They are not used in critical applications.