Sheet metal work has its own significance in the engineering work. Many products, which fulfill the household needs, decoration work and various engineering articles, are produced from sheet metals. Common examples of sheet metal work are canisters, guards, covers, pipes, hoods, funnels, boxes, etc. Various types of metal sheets are used in aircraft structural work including iron, steel, copper, brass, aluminium, duralumin, etc.
Metal sheets are classified on the basis of the material out of which these are made of. For the same metal, sheets are classified according to their thickness (gauge).
Mild Steel Sheets
These sheets are available in various sizes. For prevention against rust, these sheets are normally coated with tin or zinc. The use of these sheets is limited to articles that are to be painted or enameled.
Stainless Steel Sheets
These are basically alloy of Iron,Nickel and Chromium with small amount of carbon. Chromium is added to make these sheets rust proof. These are widely used in aircraft construction. The prime factors contributing towards its use are great strength and resistance to corrosion & general deterioration. These are used in many engineering components and home utensils also. These can be welded.
Tin Plated Sheets
These are very thin tin plated iron sheets. These are available in 1 Mtr x 0.6 Mtr sizes. These sheets have very bright silvery appearance and generally used for making food containers.
These are iron sheets with zinc coating. The coating of zinc resists rust, improves appearance, solderability & water resistance. These sheets have dull shine as compared to stainless steel sheets. These are popularly known as G.I. sheets. Articles such as pans, buckets, furnaces, cabinet, etc. are made from G.I. sheets.
These are used in aircraft chiefly in the form of tubing for fuel and oil pipelines and in most electrical parts. These are mostly used in electrical industry. These sheets are strong, soft and can be formed easily. These sheets can be easily soldered or brazed. Sometimes chromium or tin coating is also given when these are used for decorative purposes.
Brass is an alloy of Copper and Zinc. Brass sheets contain 70% Copper and 30% Zinc. These are used for household work. Its use in aircraft is limited to various pipe fittings, tanks and valves.
These are used for articles used in marine environment. These contain 85% copper and rest tin. Sometimes other elements such as zinc, nickel, aluminium, lead, etc. are also alloyed.
The characteristics of aluminium, which are the chief factor in determining its usefulness in aircraft work, are light weight, high resistance to corrosion and the ease of fabrication. Its sheets are most widely used in aircraft industry. Aluminium alloys are used for structural parts such as ribs, beams, wing skin, in engines and propellers etc. As a matter of fact, it would hardly be possible to mention any part of the aircraft in which its use has been excluded.
Other Types of Sheets
The less commonly available sheets are those of gold, silver and platinum.