The Four Strongest Materials for Plastic Fasteners

Plastic Fasteners Stronger than MetalPlastic Fasteners Strong Enough for Space

The automotive and aerospace industries have one important goal in mind. That of light-weighting their products. They need to lightweight so they can increase the performance of their vehicles, airplanes and aerospace navigational devices. However, there has been a major obstacle up until now. That of finding plastic fasteners with the same or even an improved fastener technology to that of the metal counterpart.

Today That Technology Does Exist

As we’ve discussed before, the market for plastic fasteners is growing exponentially. The reason for this explosive growth is because the plastic fastener is resistant to chemicals, acids and corrosion. It is non-conductive and tolerant of water. And although these reasons are popular, .

Do you have an application, prototype or manufacture that requires strength as well as the advantages of plastic? Check out these top strongest plastic fastener materials:

  1. FR-4/G10 Plastic

This composite material is made of woven fiberglass cloth and epoxy resin. This combination gives plastic an improved strength to weight ratio. And now the plastic screw and washer industry has found success in making plastic screws, washers and fasteners from this material. The physical properties of FR-4 are denoted by the LW (lengthwise, wrap yarn direction) and CW (crosswise, fill yarn direction). It is this combination that creates a strength of 45,000 psi which compares to brass and aluminum (Grade 6463-T6) fasteners. FR-4 fasteners are also flame resistant and have a high mechanical strength. Like all plastic fasteners, those made with FR-4 materials are electrically insulated and do not corrode. The downside is that FR-4 is not available in injection molding, but rather in rods, plates and sheets. It can be used as a coating for plastic bushings, washers, screws, bolts, nuts, switches, threaded rods and transformers.

2.Polyarylamide

Also known as PARA, this plastic material is made of a base resin with a lower and slower water absorption rate than the more conventional plastic composites. It’s resistance to water is attributed to the semi-aromtic structure of PARA. This structure is a fiberglass composite which creates a high rigidity. Additionally, it offers an excellent surface quality, high dimensional stability and has an extremely small creep. PARA 50% glass reinforced materials are also highly resistant to chemicals including those used in automotive applications. PARA has a tensile strength of 34,000 psi and the PARA 50% is a glass filled plastic fastener that is often used to replace its metal counterpart. PARA is often used in electronics, avionics, automotive, furniture, small appliance applications.

3. Thermoplastics Polyurethane (TPU)

This material is an impact modified amorphous polymer added to crystalline resins. TPU has a low uniform shrink rate and thus minimal creep. These fasteners are lighter than metal fasteners but offer a tensile strength of 27,000 psi. It also contains a high moisture and chemical resistance as well as UV resistance. This is an ideal material for plastic fasteners used in applications such as internal scaffolding products, pipe hangers, beam clamps, bolts, hex nuts, pipe clamps, clevis hangers, channel nuts and more.

4. PEEK and PPA

This material is a new compound consisting of glass, carbon which is then fiber reinforced. The benefit of this material is its ability to mold the components into a high-volume controlled process that reduces manufacturing costs. In addition, these combined materials increase the practical toughness due to lower filler loadings allowing the plastic fastener to have some flexibility and prevent fracturing.

High strength allows easy replication of original metal design

In general, even the strongest moldable plastics cannot match the strength of metals so the metal part geometry must be altered and re-engineered to utilize plastic materials. This often involves adding more material volume of the plastic which can compromise the weight savings and cost reduction advantages of the conversion to plastics. However,  new polymers offer mechanical properties that sometimes meet or exceed those of metals. The resulting component design can more easily replicate the original metal design, minimizing the mass of plastics required while realizing all of the engineering benefits of the plastic materials.

Problem Solved

For years manufacturers in the automobile manufacturing an aerospace industry have requested plastic fastener manufacturers to develop moldable thermoplastic composite bolts and screws that offer metal-like strength. The end users are looking to plastic fasteners to solve their weight problems by offering this light-weighting technology. But in prior years, we had been unable to find a polymer with enough performance to do this. Today, we are telling another story.  We now have a variety of polymer composites that can use to create this metal-like strength and bring manufacturers all of the benefits of plastics without the disadvantages.

Choosing plastic fasteners for your next project

Plastic fasteners can be the right fit for your application, but it’s extremely important that you seek professional advice before you make a purchase.

At E&T Fasteners, we are experts at understanding the benefits and drawbacks of fasteners and components that are made out of a wide variety of materials. Click here to speak to one of our knowledgeable representatives and we can help you find the right plastic fasteners for your project.