A number of new fastening innovations have come to market since the New Year. Among these is one from Sussex-based TR Fastenings, which is introducing a nut that can be used on sheet metal and plastic which is normally too thin to tap by conventional methods.
It has developed the K-Series nut specially designed for use in applications with a minimum sheet thickness of 1mm. The nut, which offers a permanent female thread, can be installed without the need for specialist tooling. Once fixed, the product offers a permanent thread with a high prevailing torque and pullout resistance.
"It is designed for use on sheets with a minimum thickness of 1mm," says Steve Wallis from TR Fastenings. "It allows a thread to be inserted in to sheets that you aren't normally able too. And it is easy to install, it is punched in to a pre-punched hole and twists in to the material. It is smaller in diameter than a lot of products out there, for example sheet metal, so it is good for those areas where space might be a premium. It is steel plated, has high torsional resistance, high pull out resistance; so it is quite a tough product."
K-Series nuts are manufactured in a case hardened carbon steel, plated and tested to ISO898, though stainless steel can be supplied to order. Sizes range from M2.5-M16, with three different spigot lengths, the body of the product is hexagon with a serrated spigot.
"It can be used anywhere where you have sheet metal and you need to put in a thread," says Wallis. "It will find applications with sheet metal contractors and fabricators, the telecommunications industry, the automotive industry, and white goods and electrical industries.
"The great thing about the K-series nut that sets it apart is that it is quite small in the hole size required and the diameter of the body. It is much smaller when compared to self clinch nuts and rivet bushes. So this gives it the other added advantage of where space is a premium, perhaps in the telecommunication or electronics industry."
Additionally, PEM Fasteners has developed fasteners to allow easier mating of the threads in thin sheet metal applications. Although this sounds relatively simple, those using the fasteners frequently will save significant time and it should help alleviate the potential of strip threading.
The fasteners possess a unique 'float' capability that enables easier mating during attachment and promotes design flexibility for relaxed tolerance applications. The family of floating fasteners includes captive panel screws and self-clinching nuts, all easily installed in thin sheets.
Floating captive panel screws can have either knurled cap or smooth cap reliably install into metal or non-metal panels as thick as 1.6mm, enabling subsequent access to an assembly and compensating for up to 1.52mm mating hole misalignment.
Its patented MAThread anti-cross threading technology corrects off-angle installations, aligns components, and slides through clogged internal threads and a shoulder on the retainer portion of the fastener helps simplify installation. Thread sizes range from 4-40 through to ¼-20, and from M3 through to M6. The fasteners are available in a scratch proof DuraBlack finish and assorted coloured plastic caps.
Floating self-clinching nuts can be specified with non locking threads or self locking threads and provide permanent load bearing threads in metal sheets as thin as 0.97mm and permit a minimum of 0.76mm adjustment for mating hole misalignment. Their unique design allows the fastener threads to extend fully into the retainer shank to impart added strength and support in an assembly.
The floating fasteners are RoHS-compliant and free part drawings can be downloaded from its website.