Aircraft Sheet Metal Numbering System

To locate structures to the right or left of the center line of an aircraft a similar method is employed.

Aircraft sheet metal numbering system. Base measurement is the outside dimensions of a formed part. The upper number in each cell is the bend allowance for a 90 bend. Bend allowance and bend radius all the space between the band tangent lines is the. The final two digits the sequence numbers are numbers that simply place the sheets in order.

The tools required for this type aircraft are minimal. Center punch the rivet then drill just to the base of the rivet head with the same size or one size smaller drill. Other aircraft kits use regular structural rivets that must be squeezed or driven. Some sheet metal aircraft utilize construction techniques that use nothing but pop rivets that are pulled using a small inexpensive rivet tool.

Manufacturers use some system of station marking. Various numbering systems are used to facilitate the location of specific wing frames fuselage bulkheads or any other structural members on an aircraft. Department of transportation federal aviation administration 800 independence avenue sw washington dc 20591 866 tell faa 866 835 5322. To determine the bend allowance for a 90 bend simply use the top number in the chart.

Aluminum lithium alloys were developed for reducing weight in aircraft and aerospace structures. Aircraft hardware is discussed in detail in the structural hardware manual navair 01 1a 8. Forming sheet metal requires a variety of tools and equipment both powered and manual. Flange is the shorter part of a formed angle.

The lower number in the cell is the bend allowance per 1 of bend. Natural grain of the material is formed as the sheet is rolled from molten ingot. Any bend formed on a. 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.

Efficient operation of any aircraft is greatly dependent upon correct selection and use of aircraft structural hardware and seals. How bend calculations are used in a bending operation. 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. Many manufacturers consider the center line of the aircraft to be a zero station.

The terms are used in sheet metal forming and flat pattern layout. Types of shrinking and stretching tools used for aircraft metal structural repair. In figure 5 the radius of bend is shown on the top line and the metal thickness is shown on the left hand column. Forming at room temperature is known as cold forming.