A rivet is a permanent
mechanical fastener. Before being
installed, a rivet consists of a smooth cylindrical shaft with a head on one
end. The end opposite the head is called the tail. On installation the
rivet is placed in a punched or drilled hole, and the tail is upset, or bucked
(i.e., deformed), so that it expands to about 1.5 times the original shaft
diameter, holding the rivet in place. In other words, pounding creates a new
"head" on the other end by smashing the "tail" material
flatter, resulting in a rivet that is roughly a dumbbell shape. To distinguish
between the two ends of the rivet, the original head is called the factory
head and the deformed end is called the shop head or buck-tail.
Because there is effectively a head on each end of an installed rivet, it can support tension loads (loads parallel to the axis of the shaft); however, it is much more capable of supporting shear loads (loads perpendicular to the axis of the shaft). Bolts and screws are better suited for tension applications.
Fastenings used in traditional wooden boat building, such as copper nails and clinch bolts, work on the same principle as the rivet but were in use long before the term rivet was introduced and, where they are remembered, are usually classified among nails and bolts respectively.
Solid rivets are used in applications where reliability and safety count. A typical application for solid rivets can be found within the structural parts of aircraft. Hundreds of thousands of solid rivets are used to assemble the frame of a modern aircraft. Such rivets come with rounded (universal) or 100° countersunk heads. Typical materials for aircraft rivets are aluminium alloys (2017, 2024, 2117, 7050, 5056, 55000, V-65), titanium, and nickel-based alloys (e.g., Monel). Some aluminum alloy rivets are too hard to buck and must be softened by solution treating (precipitation hardening) prior to being bucked. "Ice box" aluminum alloy rivets harden with age, and must likewise be annealed and then kept at sub-freezing temperatures (hence the name "ice box") to slow the age-hardening process. Steel rivets can be found in static structures such as bridges, cranes, and building frames.
The setting of these fasteners requires access to both sides of a structure. Solid rivets are driven using a hydraulically, pneumatically, or electromagnetically driven squeezing tool or even a handheld hammer. Applications where only one side is accessible require "blind" rivets.
Because there is effectively a head on each end of an installed rivet, it can support tension loads (loads parallel to the axis of the shaft); however, it is much more capable of supporting shear loads (loads perpendicular to the axis of the shaft). Bolts and screws are better suited for tension applications.
Fastenings used in traditional wooden boat building, such as copper nails and clinch bolts, work on the same principle as the rivet but were in use long before the term rivet was introduced and, where they are remembered, are usually classified among nails and bolts respectively.
Solid/Round-head
Rivets
Solid rivets are used in applications where reliability and safety count. A typical application for solid rivets can be found within the structural parts of aircraft. Hundreds of thousands of solid rivets are used to assemble the frame of a modern aircraft. Such rivets come with rounded (universal) or 100° countersunk heads. Typical materials for aircraft rivets are aluminium alloys (2017, 2024, 2117, 7050, 5056, 55000, V-65), titanium, and nickel-based alloys (e.g., Monel). Some aluminum alloy rivets are too hard to buck and must be softened by solution treating (precipitation hardening) prior to being bucked. "Ice box" aluminum alloy rivets harden with age, and must likewise be annealed and then kept at sub-freezing temperatures (hence the name "ice box") to slow the age-hardening process. Steel rivets can be found in static structures such as bridges, cranes, and building frames.
The setting of these fasteners requires access to both sides of a structure. Solid rivets are driven using a hydraulically, pneumatically, or electromagnetically driven squeezing tool or even a handheld hammer. Applications where only one side is accessible require "blind" rivets.
High-Strength
Structural Steel Rivets
Until relatively recently,
structural steel connections were either welded or riveted. High-strength bolts
have largely replaced structural steel rivets. Indeed, the latest steel
construction specifications published by AISC (the 14th Edition) no longer
covers their installation. The reason for the change is primarily due to the
expense of skilled workers required to install high strength structural steel
rivets. Whereas two relatively unskilled workers can install and tighten high
strength bolts, it takes a minimum of four highly skilled riveters to install
rivets in one joint at a time.
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