Screws, bolts, nuts, washers and other fasteners are usually made from one type of metal or another. From ordinary materials like stainless steel and aluminum to specialty metals like Inconel and Monel, it’s possible to incorporate a range of valuable properties into a fastener assembly and the structure or piece of equipment in which it’s installed.
With the diversity of benefits that metal fasteners offer, under what circumstances would a non-metal or plastic fastener be more favorable? The fact is that plastics can offer many different properties and advantages as fasteners and components.
Plastic can provide different degrees of strength and toughness, though not always on the level of conventional materials. If you’re looking for endurance that’s comparable to metal, then fasteners made from synthetic materials like nylon can deliver such qualities. Polymer-derived components, however, really reveal their value when you’re looking for the following benefits:
Flexibility And Impact Strength
While they don’t offer much in the way of strength and hardness, plastic fasteners offer ductility. They will flex under impact rather than break. They’re also softer than metal fasteners, meaning they aren’t as likely to scratch, puncture, or dent soft surfaces, finishes, and materials like plaster or drywall.
It’s true that most metal fasteners can be reclaimed for recycling but there are limits, especially if the integrity of the material is compromised due to corrosion and other types of wear. As plastics resist many of the factors that cause corrosion and material breakdown, they retain their integrity and can be easily recycled and reused.
If the flow of electricity needs to be carefully contained within an application, then using metal fasteners can be a big mistake. Plastic is naturally nonconductive and therefore provides reliable electrical insulation within an industrial application. Plastic fasteners can also offer more longevity and stability compared to other electrical insulating materials like fiber and rubber.
Plastic fasteners are typically less expensive than those made from metal. They can also offer improved longevity as a result of their resistance to common factors that cause breakdown in various metals, and therefore do not need to be replaced as often. This amounts to better overall economy.
Chemical And Corrosion Resistance
One of the most valuable benefits of using plastic fasteners is their resistance to various chemicals and common causes of corrosion, like exposure to saltwater or acidic substances. Plastic’s inherent resistance to certain substances makes it a regular choice for use in chemical and food processing applications. It can also serve as a buffer between incompatible materials to prevent chemical reactions and leaching. Polyethylene flat washers, for example, can be used between a metal screw or bolt and a painted or coated surface. This will serve to prevent any chemical reactions that may occur over time.
Before you decide to use plastic fasteners in a piece or equipment or structural setting, make sure you consult with an expert and verify application specs to ensure that plastic components are a suitable option.