Advantages of aluminum alloy threaded fasteners

Aluminum is a kind of silver-white light metal with good ductility and malleability. It is easily soluble in dilute sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solution and is insoluble in water. Aluminum commodities are often made into rods, sheets, foils, powders, ribbons, and filaments. Aluminum can form an oxide film that prevents metal corrosion in humid air. Aluminum powder and aluminum foil can burn violently in the air and emit a dazzling white flame. Aluminum is widely used for its light, good electrical and thermal conductivity, high reflectivity and resistance to oxidation.

Under normal circumstances, aluminum has sufficient corrosion resistance. And when the expected exposure environment is very harsh, its corrosion resistance can be greatly improved by anodizing. Anodic treatment is an electrical process that forms an oxide film on a metal surface. Anodic treatment not only enhances the ability to resist corrosion, but also enhances protection against wear and scratches. Anodic coatings are available in a variety of colors for decorative and identification purposes. In atmospheric corrosion, aluminum forms a light gray oxide film on the surface. These corrosion products do not contaminate the surface of the aluminum, or spread to adjacent surfaces. It is not the same as many other metals under the effect of corrosion.

Pure aluminum has a tensile strength of approximately 13,000 psi, and it is possible to increase the amount of alloying elements and greatly improve the strength. Aluminum alloys of 2XXX, 6XXX, and 7XXX are very effective for heat treatment. Therefore, virtually all threaded fasteners used for load transfer are made from these three major types of aluminum alloys. There are four kinds of aluminum alloys that are almost exclusively used.

The weight of aluminum fasteners is 1/3 of the weight of their equivalent steel fasteners, and the strength characteristics of this commonly used alloy are surprisingly good. In fact, in terms of strength ratio, aluminum fasteners are higher than any other fasteners made from industrial and trading materials. Aluminum is non-magnetizable. The thermoelectric conductivity of aluminum is very good, about 2/3 of that of copper in the same volume. Aluminum has good processing characteristics, easy cold forming and hot forging.