Aerospace Fasteners: 3 Materials Explained

The U.S. screw, nut, and bolt industry is vast. There’s a reason over 131,949 people are employed by it; with fasteners being used in just about every facet of human life — from the tiny screws in our bed frames to the miniature screws and custom shoulder bolts used on the International Space Station — it’s vital that there be a wide variety of fastener options and materials available to work with.

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When it comes to aerospace bolt applications, materials are crucial; since certain metals and alloys can’t stand the extreme conditions that occur as spacecraft leave the earth’s atmosphere or get exposed to burning rocket fuel, the fastener industry must account for these problems. Let’s take a look at three of the materials commonly used in aerospace fastener applications.

• Steels: Although steels are very strong, hard alloys, they are also very heavy; this can cause problems for air- and spacecraft. Generally speaking, stainless steel and alloy steels are used, but the type of stainless steel matters as some are too susceptible to heat damage and failure. Series C300 corrosion resistant (CRES) stainless steel is often used for aerospace screws and custom shoulder bolts because of their durability.

• Superalloys: As their name suggests, these high-performance alloys can maintain integrity in higher temperature environments; in fact, some types (such as A286) can withstand temperature extremes between -420 degrees Fahrenheit and 1,200 degrees Fahrenheit. Inconel 718, a nickel-based superalloy, retains a 220ksi (kilopound per square inch) tensile strength up to 900 degrees Fahrenheit. In situations where exposure to the severe heat of re-entering the planet’s atmosphere (as well as the burning fuel itself) is a given, only the most heat-tolerable metals and alloys will do.

• Titanium: Occasionally, aerospace rivets will be made from titanium because of its similarities to steel and alloy steel strength; the benefit of titanium is that the material is exceptionally lightweight. It is also more heat and cold resistant than steel, tolerating ranges between -350 and 800 degrees Fahrenheit.

This article proves that the material fasteners are made out of is just as important as the type of fastener used. If your project deals with extreme temperatures, exposure to corrosive elements, or any other harsh conditions, it’s vital that you procure fasteners that are able to stay strong through it all.