Aviation and Aerospace Fastener Catalog - Page 3

Fasteners are small devices that form connections between two separate physical components. The connections close a gap or secure a bridge. While fasteners are required to be rigid, they are not designed to create permanent connections. Example of common fasteners include bolts, cable ties, clips, clutches, bolts, buttons, and clamps. While ropes and hinges form connect two components together, due to their wide variety of applications, they are not classified as fasteners

Fasteners are usually required to have certain properties in order to be integrated within a mechanism. Materials such as aluminum and titanium are popular as they are lightweight. Fasteners are often coated to reduce corrosion and improve long term performance.

We at NSN Purchasing, owned and operated by ASAP Semiconductor, supply fasteners from top manufacturers across the globe. Some of the manufacturers that provide premium fasteners are Eaton Aircraft, Huck International, PCC Fasteners, LISI Aerospace, Monogram, Arconic, and 3V Fasteners.

A key aspect of fasteners is the standards that they must abide by. The shape, composition, size, and design of a fasteners must be uniform. While the American Society for Testing and Materials (ASTM) have their own set of standards, the standards that are referenced more often are: MS, NAS, NS, and BAC. These different sets of standards are provided by the military, NASA, navy, and Boeing.

A key military standard is traceability. A fastener used on a military machine must be traceable back to the factory supply chain. A malfunctioning fastener could jeopardize the overall integrity of a machine therefore becoming a safety risk.

When referring to fasteners, such things as drive types, washer types, nut types, and anchoring products are referenced.

Drive types include: combination, one way, square, and slotted.

Washer types include split lock, square, fender, flat, and dock.

Nut types include heavy hex, wing, cap, flange, tee, square, k-lock, and pin lock

Anchoring products include drop-in anchors, double expansion sleeves, conical anchors, and stud anchors.

Aerospace Fasteners

Fasteners used in aircraft are required to withstand extreme temperatures and pressures. Due to the conditions, fasteners are made up of a few common materials. Aluminum is used on aircraft, but not spacecraft. An alternative material are steel alloys. The durability of steel is desirable; however, the weight is not. Steel alloys overcome this problem, although they are susceptible to corrosion. CRES Series 300 Steel is common for screws and bolts.

Titanium can be used as an alternative to both aluminum and steel. Titanium is lightweight yet is just as strong as steel.

Automotive Fasteners

The most commonly used fasteners in automobiles are nuts, studs, and bolts. The Society of Automotive Engineers (SAE) have a set of regulations that govern the manufacturing of fasteners used in the automotive industry. For safety reasons, fasteners must be uniform in design, shape, and composition.

Automotive Bolts

TThe main characteristics of a bolt are the thread and the head. Bolts are rigid and strong. They are used in areas of a machine where there needs to be a tense connection. Bolts have a longer grip length, with a shorter thread length to accommodate a nut.

Automotive Nuts

Typically, automotive nuts are hex or square, with a threaded hole in the middle. Put simply, nuts fasten and secure bolts. The shape and type of nut should correspond with the type of bolt.

Automotive Studs

Studs are characterized by two threaded ends and a smooth middle section. Nuts are used to secure the studs in place. Nuts are more durable than bolts so are typically found in more intense conditions such as in cylinders. Studs are made of materials such as aluminum, copper, and bronze.

The SAE has a grading system for fasteners. SAE grades 2,5, and 5.8, 8.8, 10.9, and 12.9 metric grades are used in the automotive industry.

Marine Fasteners

Typically, marine fasteners are made of stainless steel. CRES Series Steel 18-8, 304, and 316 are used in marine mechanical systems. The key benefit of stainless steel is its resistance to corrosion. Marine fasteners come into close proximity with salt. The lifespan of a fastener that is not resistant to corrosion is significantly less than one that is. Fasteners can be made from stainless steel that is dipped in zinc. These fasteners are stronger and even more resistant to corrosion.

An alternative to steel is silicon bronze. Fasteners that are in contact with water are usually made out of this material. Silicon bronze performs well in adverse conditions such as below the waterline. The parts of a marine craft that are underwater should be connected by silicon bronze fasteners.