The two major types of rivets used in aircraft are the common solid shank rivets, which should be driven having an air-driven gun and bucking bar; and special (blind) rivets, which are installed with special installation tools. Solid shank rivets are employed widely during assembly and repair work. They are identified by the material of which they are made, the top type, size of shank, and temper condition.
The material employed for the majority of solid shank rivets is aluminum alloy. The strength and temper conditions of aluminum alloy rivets are identified by digits and letters just like those used to spot sheet stock. The 1100, 2017-T, 2024-T, 2117-T, and 5056 rivets would be the six grades usually available. AN-type aircraft solid rivets can be identified by code markings on the rivet heads. A rivet manufactured from 1100 material is designated being an “A” rivet, and has no head marking. The 2017-T alloy rivet is designated as a “D” rivet and has a raised teat on the head. Two dashes on a head Aerospace rivets indicate a 2024-T alloy designated as a “DD” rivet. The 2117-T rivet is designated as an “AD” rivet, and has a dimple on the head.
A “B” designation is directed at a rivet of 5056 material and is marked with an elevated cross on the head. Each type of rivet is identified by a part number to permit an individual to choose the right rivet. The numbers are in series and each series represents a specific kind of head.
Countersunk head rivets are utilized the place where a smooth finish is desired. The 100-degree countersunk head has been adopted as the typical in the United States. The universal head rivet (AN470) has been adopted as the standard for protruding-head rivets, and may be used as a replacement for the roundhead, flathead, and brazier head rivet. These rivets can also be purchased in half sizes by designating a “0.5” after the main length.
Replace rivets with those of the exact same size and strength whenever possible. If the rivet hole becomes enlarged, deformed, or else damaged; drill or ream the hole for the next larger size rivet. Rivets might not be replaced by a type having lower strength properties, unless the low strength is adequately compensated by an increase in proportions or a greater amount of rivets. It is acceptable to restore 2017 rivets of 3/16 inch diameter or less, and 2024 rivets of 5/32 inch diameter or less with 2117 rivets for general repairs, pro vided the replacement rivets are 1/32 inch greater in diameter than the rivets they replace.
Rivet edge distance is defined as the distance from the centre of the hole to the nearest edge of the sheet. Rivet spacing is the distance from the centre of the rivet hole to the centre of the adjacent hole. Unless structural deficiencies are suspected, the spacing and edge distance should duplicate those of the initial aircraft structure. If structural deficiencies are suspected, the next can be utilized in determining minimum edge distance and rivet spacing. Special fasteners may require an FAA field approval.
Blind rivets are employed under certain conditions when there is use of just one side of the structure. Typically, the locking characteristics of a blind rivet are not just like a driven rivet. Therefore, blind rivets are often not used when driven rivets may be installed.
The 2117 rivets might be driven in the situation received, but 2017 rivets above 3/16 inch in diameter and all 2024 rivets should be kept packed in dry ice or refrigerated in the “quenched” condition until driven, or be re heat treated just just before driving, as they would otherwise be way too hard for satisfactory riveting.