Grommets are an often under-appreciated mechanical component. While you can find grommets in a wide range of applications across nearly every engineering discipline, the average person is unlikely to spend much time thinking about them. Despite their relative obscurity, these simple rubber components can be essential to the reliability of many machines, vehicles, and systems.
If your project requires grommets to protect wiring, seal exposed surfaces against moisture, or protect a cut edge from rubbing, choosing the wrong grommet can have serious implications. Your grommets must hold up to their intended application while remaining durable over your product’s expected lifespan. This guide will discuss three factors to help you choose the correct grommets for your needs.
1. Recognize Mission-Critical Use Cases
Mission-critical use cases exist where a parts failure can affect a product or system’s reliability, safety, or operation. While the importance of grommets can be easy to overlook, these simple rubber rings can have some surprisingly profound impacts on long-term reliability. In particular, any area where wiring may rub against a sharp, exposed surface without a grommet is a potentially mission-critical area.
Water infiltration is a major concern. Rubber grommets for marine applications typically need to prevent water from dripping through openings where ropes or wires must pass between compartments. This use case qualifies as mission-critical since water may damage sensitive electrical components, and saltwater can present a serious corrosion hazard.
In general, you should always consider the consequences of any grommet failure, especially one that can go unnoticed for a long period. Damaged wiring or moisture intrusion can pose serious hazards, including fires, shock risks, or long-term reliability issues. If a worn-out or failed grommet can create these issues, always give sizing and material selection special care and consideration.
2. Understand Material Options
Rubber is a catch-all term that can refer to numerous more specific materials. While most people probably think of natural rubber when considering die-cut or molded rubber products, manufacturers use various materials and blends to produce rubber suitable for usage in many environments and conditions.
Ethylene propylene diene monomer (EPDM) is one of the more common and modern forms of synthetic rubber. EPDM is a common material for commercial roofing because it offers good temperature resistance, durability, and a reasonably long lifespan. Its low electrical conductivity is another point in its favor for grommet usage since it can help protect against shock risks with damaged cable insulation.
On the other hand, mission-critical areas with significant exposure to oils or other chemicals may require materials such as nitrile (also known as Buna-N) or SBR. If your grommets will be operating in these environments, working with an experienced rubber supplier is crucial to ensure they perform as expected and do not experience premature wear or failure.
3. Choose Appropriate Grommet Styles
Grommets are more than simple rings that cover the exposed edges of holes. Grommets come in numerous sizes and styles to fit different applications. While using the wrong grommet to cover a wiring hole in an office desk probably won’t have any significant consequences, an incorrect grommet in a vehicle engine bay or factory machinery can cause serious safety issues.
Standard grommets are appropriate for quick installation in sheet metal or other materials, and their primary role is to protect cabling from exposed metal. These grommets do not provide significant insulation against heat, moisture, or chemicals. On the other hand, sealing-style grommets are crucial when a water or chemical-tight seal is necessary.
Sizing and installation concerns are also crucial. Many grommets snap directly into place, but some may require special tools, and large grommets may require easy access for installation or removal. Consider future maintenance and repair needs in any area where grommets are mission-critical. As a result, quick-fit or push-in style grommets are often a better choice for difficult-to-access areas.
Accurate Products Inc. manufactures a wide range of standard and custom grommets suitable for nearly any application. We can supply you with grommets that can withstand harsh conditions daily and continue to perform as expected. Get in touch today to discuss the best options for your industry’s requirements.