For secure locking and reusability with no tangs to remove, Spiralock introduces its new 2-56 Drive Notch™ (DN™) tang-free Wire Thread Insert. The Spiralock 2-56 DN insert represents a tremendous engineering achievement, overcoming the difficulties encountered when forming the wire and coiling to produce such a small size Spiralock insert. Engineers and designers now have the ability to call out Spiralock 2-56DN inserts on their drawings, typically used in softer materials such as aluminum or where thread integrity, secure locking, and reusability are of utmost importance.
The Spiralock DN inserts feature Spiralock’s patented 30-degree “wedge” ramp formed into a unique 5-sided wire. When wound into a coil shape, it creates the ramp at the root of the female thread. Under clamp load, the crests of the threads on any standard male bolt are drawn tightly against the wedge ramp. This eliminates sideways motion that causes vibrational loosening and distributes the threaded joint’s load throughout all engaged threads, a claim supported by a Massachusetts Institute of Technology research study. The load percentage on the first engaged thread is significantly lower than traditional thread forms, which further reduces possible bolt failure and improves product performance. The flexible coils provide a balanced distribution of dynamic and static loads compensating for errors in the tapped threads allowing each coil to share the load evenly.
Spiralock inserts have extensive reusability without the potential for damaging internal threads. They are made of SS304 material and have an ultimate tensile strength above 200KSI. Therefore, in materials such as aluminum, a Spiralock tapped hole will have an ultimate tensile strength around 35KSI. Using a Spiralock wire insert in place of a Spiralock tapped hole will greatly increase sheer strength of the internal thread. The Spiralock inserts will not become damaged and will typically be the strongest component in your threaded assembly. Spiralock wire inserts can be particularly effective in industries such as aerospace, electronics, and medical. In aerospace, for example, the wire inserts are used in applications ranging from circuit board clamps and satellite connectors to avionics box enclosures and electronically scanned arrays. In electronics, they are used in applications such as heat sinks, cover plates, and chassis product housings. In medical, they are used in applications such as imaging, monitoring, and sterilization equipment
Unlike tanged wire inserts, which require breaking off, retrieving and accounting for tangs, the DN Wire Thread Inserts require no such extra steps. Using the Drive Notch installation tool or standard tangless tooling, the inserts install per MS33537 wire insert installation spec, with appropriate STI taps and gages. In addition, they meet the applicable parts of the procurement specification NASM8846 and NAS1130 Inserts. DN inserts eliminate the possibility of loose tangs short-circuiting electronics or causing foreign object damage. They also prevent harm to expensive castings caused by invasive tang removal techniques. Another benefit is their space and weight advantage over solid bushing type inserts, which allows the inserts to be designed into reduced diameter bosses and flanges, and into hard to reach areas.