In the construction of a metal air frame, permanent joints are made either with rivets or bolts. To securely attach structures together, rivets are cheaper to use, lighter and more rapidly fitted than nuts and bolts, but in the case of power operated machine riveting, more extensive equipment is usually required to make the permanent joints.
Solid rivets have the greatest strength and are therefore preferable to any other type of rivet, but they can only be used where there is access to both sides of the structure.
Rivets are always supplied to the operator with one head already formed and the shank plain to permit insertion into the hole, the opposite end being formed into a head by manual or mechanical means. The size of a rivet is expressed as the diameter and length of its shank; the exception is the countersunk rivet where the length is inclusive of the head
- SNAP HEAD : for general purposes where strength is required but not a streamline finish.
- MUSHROOM HEAD: for skin covering to give maximum strength.
- FLAT HEAD: for internal work where heads are not easily accessible
- COUNTERSUNK: for flush finish (90°, 100°, 120° head) in aviation mostly used 100°
- RAISED COUNTERSUNK : for more streamlined surfaces.
- UNIVERSAL HEAD
- 100° COUNTERSUNK TRUNCATED RADIUS HEAD: