Different types of rubber grommets are commonly used in various applications to protect, isolate, seal, dampen, cushion, or secure items that pass through a hole or opening, or contact each other. A small, yet essential component, grommets are typically made from a variety of rubber materials. Silicone grommets or neoprene grommets, for example, are different types of rubber material used for specific applications.
Types of Rubber Grommet Designs
There are many different types of rubber grommet designs, too. Not all grommets are doughnut shaped, though those familiar open rubber grommets with a central hole are the most basic design. There are also closed rubber grommets, sometime called blind rubber grommets, that provide air-tight seals to block dust. Rubber blanking plugs are used to seal holes. Rubber grommet strip designs sit along the edge of a panel or plate to smooth its edge. Push-in grommets are ideal for applications like control panels where space is limited and can be pushed in unthreaded holes without the need for tools. Sealing grommets are a waterproof, all-weather cable grommet that easily snaps into round holes and can dampen vibration as well as withstand oily and greasy environments.
Horseshoe grommets are used to seal and insulate a wire bundle pulled into an electronic enclosure. Medical plunger grommets, as the name suggests, are rubber stops used to seal test tubes or flasks in laboratories. Another type of medical grommet, a tiny ventilation tube, is inserted into the eardrum to treat glue ear and recurrent build-up of fluids. Grommet button bumpers or push in grommet bumpers are used extensively in automobiles, trucks, boats, docks, appliances and door frames to prevent metal-to-metal or surface-to-surface contact.
Grommet Rubber Material Options
The choice of rubber material for a grommet depends on the specific requirements of the application, including factors like temperature, exposure to chemicals, UV resistance, and flexibility. To ensure the grommet performs as intended, consult with your supplier to make certain the appropriate material is selected. The most common types of rubber materials used for manufacturing rubber grommets include:
Silicone
Silicone rubber is a highly-resistant elastomeric material made of polymer silicone joined by carbon, hydrogen and oxygen molecules. The structure has many excellent mechanical properties, among them thermal stability, durability, extreme temperature resistance, both high and low, and high flexibility. Because of its excellent mechanical properties, grommets consisting of silicone rubber are used in applications in industries ranging from automotive and aerospace, medical and healthcare, food and beverage to electronics and electrical, textiles and footwear, and building and construction.
Neoprene
Neoprene rubber grommets are used for sensitive wiring and cabling applications to protect them from cuts, shearing, nicks or other kinds of physical damage. Resistant to oil, heat, and weathering, Neoprene rubber grommets are suitable for applications that require protection against harsh environments or exposure to chemicals. They also provide dust and moisture protection.
EPDM
EPDM (Ethylene Propylene Diene Monomer) is a long-lasting, durable synthetic rubber material used in manufacturing grommets. EPDM grommets are employed in sealing applications to protect wires, cords, and cabling components from sharp edges, wear and tear, as well as to dampen vibrations. It is extremely resistant to high temperatures, water, steam, and other types of liquids including chemicals. They are known for their excellent resistance to UV radiation, ozone, and weathering, which make them useful in outdoor applications.
Buna-N
Buna-N known by other names—Nitrile Butadiene Rubber, Nitrile rubber or simply NBR, is a widely used industrial elastomeric, general-purpose materials. Buna-N grommets are regarded for their excellent resistance to petroleum-based oils and fuels, chemicals, hydraulic fluids, silicone greases, and even water and alcohols. The material has good tensile strength, elongation, and abrasion resistance properties. Used for oil resistant applications of all types, in aircraft, automotive, and marine fuel systems, off-road equipment, and low temperature military applications (see below).
Mil-Spec MS-35489
MS-35489 grommets are a high-quality, military grade rubber grommet designed to meet demanding military and industrial application requirements. Manufactured using BUNA-N, MS-35489 grommets are resistant to oil, ozone, ultraviolet rays, and coolant, and is used to protect sensitive tubing, wiring, and control cables, among other applications.
Viton
Viton (FKM) is a specialized fluoropolymer elastomer rubber material. Grommets manufactured with Viton are highly resistant to a wide range of chemicals and have excellent heat resistance, making them suitable for chemical processing and high-temperature applications. They are typically used in marine, automotive and construction industrial applications.
SBR
SBR (Styrene-Butadiene Rubber) grommets are a cost-effective, general-purpose grommet used in a wide range of applications, especially those involving water and compression. In fact, the material is one of the most widely used synthetic rubbers produced today. SBR grommets are known for their strength, wear, stability, and bonding properties, and are also regarded for their superior heat-ageing properties and abrasion resistance. They are commonly used to cover sharp edges and prevent abrasion of the material that they are mounted on, and hide or protect wires, and minimize vibration.
Natural Rubber (NR)
Natural rubber grommets are made from the latex of rubber trees. They are known for their high elasticity and resilience, making them suitable for applications where flexibility is crucial.
Contact the Experts at Manufacturer’s Rubber and Supply
For more information on rubber grommets and their applications, or to ensure the rubber grommet performs as intended for your application, consult with the experts at Manufacturer’s Rubber and Supply. We are a leading source for many different types of rubber grommets used in industrial, commercial, and military applications. To learn more about any of our wide range of rubber products, contact us today.
