Aircraft Sheet Metal Numbering System

The tools required for this type aircraft are minimal.

Aircraft sheet metal numbering system.

To determine the bend allowance for a 90 bend simply use the top number in the chart. Other aircraft kits use regular structural rivets that must be squeezed or driven. Once drilled use a pin punch to tip off the rivet head and drive the remaining shank out of the hole while supporting the surrounding metal. Flange is the shorter part of a formed angle.

Aircraft hardware is discussed in detail in the structural hardware manual navair 01 1a 8. Manufacturers use some system of station marking. Any bend formed on a. How bend calculations are used in a bending operation.

Many manufacturers consider the center line of the aircraft to be a zero station. Natural grain of the material is formed as the sheet is rolled from molten ingot. To locate structures to the right or left of the center line of an aircraft a similar method is employed. Forming at room temperature is known as cold forming.

Some sheet metal aircraft utilize construction techniques that use nothing but pop rivets that are pulled using a small inexpensive rivet tool. Bend allowance and bend radius all the space between the band tangent lines is the. In figure 5 the radius of bend is shown on the top line and the metal thickness is shown on the left hand column. Types of shrinking and stretching tools used for aircraft metal structural repair.

Various numbering systems are used to facilitate the location of specific wing frames fuselage bulkheads or any other structural members on an aircraft. Base measurement is the outside dimensions of a formed part. Aircraft technician relies on a wide variety of powered and hand operated tools to precisely bend and fold sheet metal to achieve the perfect shape. Aluminum lithium alloys were developed for reducing weight in aircraft and aerospace structures.

Department of transportation federal aviation administration 800 independence avenue sw washington dc 20591 866 tell faa 866 835 5322. The upper number in each cell is the bend allowance for a 90 bend. As mentioned above the unified numbering system for metals and alloys uns was developed by astm and sae in an effort to clear up the alphabet soup problem. Aircraft hardware is usually identified by its specification number or trade name.

Center punch the rivet then drill just to the base of the rivet head with the same size or one size smaller drill. The lower number in the cell is the bend allowance per 1 of bend. The terms are used in sheet metal forming and flat pattern layout. Forming sheet metal requires a variety of tools and equipment both powered and manual.