When you should consider plastic fasteners vs. metal fasteners

Depending upon the application, plastic fasteners may be an excellent alternative vs. machined metal fasteners.  In fact, because of their properties and advantages, plastics are even used as a primary fastener in space applications, and are even used on the Hubble Telescope and the International Space Station.  But for more down-to-Earth needs, which should you consider? In some cases, plastic fasteners are still a great choice.  Here’s some of the advantages of plastic materials:

Plastic Fasteners don’t Rust

With few exceptions, metal fasteners will corrode and develop rust over time, particularly when exposed to constant moisture or salty conditions.   As those metal fasteners corrode, the strength of the fastener will degrade.  On the other hand, plastic fasteners will never rust or corrode.  In salt-water conditions, perhaps the best plastic fasteners to consider include those made with materials such as PVC, Isoplast and PET.  The properties of those materials including their high strength to weight ratio, the inability to absorb water, their chemical inertia, and their imperviousness to corrosive substances like diesel fuel, gasoline, or saltwater.

Plastic materials are UV resistant

Here’s why they are used it space – they are significantly more capable than metal fasteners of withstanding UV rays.  Plus, in marine applications, purchase bolts and screws made from materials that don’t absorb UV energy.  However, there are some plastics that absorb UVs and tend to develop free radicals that corrode the material faster. In cases where you need UV protection, consider plastic fastener materials such as polyimides or FEP.

Ben Franklin wouldn’t use them for experiments with lightning

Plastics are nonconductive, making them an excellent choice in electrical or electronic applications.

Common Plastic Fasteners are Typically Less Expensive

You may notice that plastics are used heavily in the automotive industry, particularly as a nod to cost cutting.  Plastic screws and bolts, for example, can cost can cost a small fraction of their equivalent metal counterparts.  So in products that include a lot of fasteners, the savings can add up.

Plastics are Versatile

Plastics are considered for fastener applications where weight, thermal, environmental, chemical, and electrical properties are a significant consideration for end use. Plastic materials can meet a broad spectrum of design requirements and could be examined for strength, light weight, flexibility or rigidity, low temperature, chemical and corrosion resistance, sealing, toughness, and outstanding electrical properties.

The design and assembly of plastic fasteners can be simplified  – sometimes a single plastic fastener can replace several metal components.

For threaded plastic fasteners including screws, bolts, rods, studs, and nuts, there’s no difference in thread classes vs. metal fasteners, so you can easily replace metal with plastic.

Colors Colors Everywhere

In addition to being available in standard shapes, plastic fasteners can be created in any color, and won’t be visibly ‘scratched off” (unlike metal which must be painted or coated).

You want strength?  I got your strength right here

If you need super strength, opt for a plastic fastener with a metal core. Most plastics can be used together with metal such as steel to create heavy duty and durable fasteners that employ the best advantages of both plastic and metal.