Shur-Lok Company

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.

Locked studs and inserts were designed for resistance to high torque-out and pullout loads. Both products utilize a lockring that prevents the stud or insert from backing out. These products are ideal for high fatigue and vibration environments found in gearboxes, turbo machinery, and vehicles for both aerospace and military markets. Various materials and finish combinations are available as well as internal thread-locking feature.

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.

Now Shur-Lok Company is applying its talents and respected Ring Locked brand name to the design and manufacture of rhydraulic fittings and fluid adaptors. Fittings will not rotate when connecting fluid lines to engine housings, gearboxes, manifolds...etc. Unlike heavier MS fittings that require a lock wire to prevent rotation, fluid fittings are held in place by a serrated lock ring. The fitting and lock ring are supplied as an assembly to simplify installation. Once the fitting assembly is threaded into the port and torqued to provide proper sealing, the lock ring is driven into the standard prebroached port to prevent the fitting from turning. The unique port end configuration results in a lower stand-off that provides for the design of a compact boss. Installation and removal of the "B-nut" is easy because only one wrench is required. Fluid fittings are designed for applications in fuel or fluid systems of aircraft, helicopter, and engines. Qualified to SAE inch and metric standards, these fittings are certified to operate in systems pressurized to 3, 000 PSI, 4, 000 PSI, 5, 000 PSI or 8, 000 PSI, and designed to exceed operating temperatures of -65F to 450F (-48C to 218C).

Bearing Locknuts are designed for shaft or spindle applications in aircraft engines, gearboxes and transmissions. The Ring Locked positive locking system minimizes keyway stress and loss of torque preload. The heart of this system is a serrated washer that is installed on a serrated shaft, then snaps over or into the nut to retain it. When serrations in the washer mate with serrations in the nut, the system can also be used on keyed shafts. Prevailing torque locknuts are typically custom design for specific applications. These nuts are available in advance aerospace alloys with either internal or external threads, internal or external wrenching slots or holes and metallic or nonmetallic locking devices.

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.