Shur-Lok Company

United States

Expandable diameter fasteners are custom-engineered to expand in a hole to prevent fretting. These unique fasteners can eliminate the need for expensive close tolerance machining or press fits. Typical applications include: aircraft engine mounting, helicopter blade attachment, mounting of anti-friction bearings, and redesigns requiring a tighter joint. The heart of the fastener is the expandable bushing stack of alternating tapered split bushings. When a compressive force is applied to the ends of the bushing stack, the diameter of the fastener increases. When the force is relaxed, the bushings return to their original diameter, and the fastener can easily be removed and reused. The family of expandable diameter fasteners include: bolts, blind bolts, shafts, and cam-operated pins.

In many ways fiber-reinforced advanced composites are stronger than metallic structures, but they do not respond well to localized concentrated loading. Three types of special fasteners have been developed to address this issue and others, such as galvanic compatability, interference fit, hold edge crushing, vibrations, and water absorption. The types: bonded-on, bonded mechanical, and nonmetallic potted-in. The bonded-on type includes studs and insert plates supplied with pre-attached thermoplastic adhesive. The adhesive is melted by applying heat to the fastener. The bonded mechanical type uses a combination of adhesive and mechanical means for retention in the structure. The nonmetallic inserts and spacers (sleeves and plugs) are primarily designed for sandwich structure. The primary material is polyetherimide which is non-reactive with current composites and is very lightweight.

Isolator mounts are designed to reduce vibration, noise and heat transfer to the interior of aircraft. These neoprene or silicone rubber and metal fasteners are typically installed between the exterior fuselage and interior aircraft passenger walls. Types include nuts with thread lock or quick-release receptacle when frequent removal is required.Blind Inserts are installed from one side and are typically used in sheet metal applications where high-torque is required. Types include flush or plus flush heads, locking or nonlocking, carbon or stainless steel. Special inserts have been designed for a variety of applications in sheet metal, wood, or sandwich structure. An insert may have been already designed that will fit your special requirement.