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Guide to Rubber Plugs & Bungs: Types, Uses, and Advantages
What are Rubber Plugs?
Rubber Plugs are simple sealing solutions that are generally designed to be pushed into holes, usually within a container. They are shaped and sized in a way that allows them to form a very tight seal. This can be made watertight and even airtight in the right conditions and that is useful for variety of applications.
What are Rubber Plugs also known as?
Rubber Plugs are also commonly called Rubber Stoppers, Rubber Bungs or Rubber Corks. These are used interchangeably across different industries and regions. The term "corks" stems from the cork material being commonly used in the past. In scientific or laboratory based industries, they will tend to use "stoppers". In homebrewing, fermentation or industrial applications, "bungs" is more popular. However, all terms are referring to the same kind of push or tap to fit sealing solution.
What are Rubber Plugs used for?
In the UK market, rubber bungs are commonly used for a wide range of sealing applications across many different industries.
Laboratories
Fermentation & Distilleries
Homebrewing
DIY uses
Industrial Sealing
Scientific Research
Food Processing
Sailing & Marine
Key Advantages of Plugs
When deployed as sealing solutions, Rubber Plugs offer several key advantages. The most important is their ability to form watertight and airtight seals with a simple push to fit or tap to fit application. Using natural or synthetic rubber materials offers high levels of temperature, chemical resistance and durability.
This is most striking when comparing the performance of Rubber Plugs to Cork Plugs that were commonly used in the past. Rubber is much more durable and allows rubber bungs to last much longer than cork. A long product lifespan increases their value, cost-effectiveness and their reusability makes them an eco-friendly solution.
Finally, Rubber Plugs can be customised to incorporate different materials, designs, shapes, sizes and features. This allows them to be tailored into bespoke solutions that meet the specific requirements of different industrial applications.
| Feature | Included |
|---|---|
| Airtight Seals |  |
| Watertight Seals | |
| Versatile | |
| Long lifespan | |
| Reusable | |
| Eco-Friendly Solution | |
| Customisable | |
| Chemical Resistant | |
| Temperature Resistant | |
How do Rubber Plugs & Bungs vary?
The material used, along with shape and size of the bung often tailor it to specific applications. Some bungs may also be designed to include specific features such as holes or ribs to cater to certain use cases.
Materials:
There is a great choice of materials available when choosing a Plug. Each have varying levels of heat resistance, chemical resistance, durability and cost. If your application requires a high temperature or any contact with chemicals you should choose a material with appropriate ratings. If that is not required then a general rubber material such as EPDM will provide a good balance of durability and cost.
Natural Rubber:
Low end heat resistance, safe for operating temperatures up to 80°C. It has a limited chemical resistance, while resistant to acids and alkalis it is vulnerable to oils, solvents and ozone. High tensile strength and tear resistance but poor resistance to UV and weathering. Not recommended for outdoor use. Low in cost, can be a cost-effective solution.
Neoprene Rubber:
Moderate heat resistance, for operating temperatures up to 121°C. Good resistance to oils, petroleum products and weathering. Vulnerable to strong acids. High durability, excellent abrasion and tear resistance. Peforms well in outdoor and industrial environments. Moderate in cost.
Silicone Rubber:
Exceptional resistance to temperature extremes with safe operating temperatures up to 250°C. Excellent chemical resistance to alkalis and oils but weak to acids. Highly durable, even under high temperature. High cost, one of the most expensive rubber materials.
Cork:
Low heat resistance, up to 60°C. Limited chemical resistance and vulnerable to any harsh chemicals. Low durability, biodegradable and will break down faster with exposure to liquids. Low initial costs but will need to be replaced more frequently than rubber materials.
Nitrile Rubber:
Moderate heat resistance up to 121°C. Excellent chemical resistance to oils, fuels and solvents but weakened by UV or ozone exposure. High durability with good tearing and abrasion resistance. Middle to high cost, higher than neoprene but offers a better chemical resistance.
EPDM Rubber:
High heat resistance up to 177°C. Excellent chemical resistance to UV, ozone and most chemicals, but prone to oils. Highly durable, suitable for outdoor use thanks to resistance to weathering and abrasion. Moderate cost, but a cost-effective solution when its high durability and reusability can be leveraged.
Plastic Bungs:
Low end heat resistance, around 60°C depending on the plastic type. Does vary by type of plastic but generally good resistance to chemicals. Lower durability than rubber materials, less flexible than rubber. More brittle and likely to break under pressure. However, low cost and better reusability than cork.
Glass:
High heat resistance, up to 200°C for standard glass. Treated glass can operate beyond 400°C. Excellent chemical resistance, able to withstand most chemicals, acids and solvents. Durable in the sense it won't be weakened by heat or chemicals. Fragile to physical impacts. High cost and potential breakages should be factored in.
Shapes, Sizes and Design Features
Rubber Plugs are a versatile sealing product and over time many variations have been created to suit the specific needs of applications across different industries. In addition to the materials used, the shape, size and additional design features often define different types or styles of Plug. Here are some common examples that are in high demand in the UK market:
Tapered Rubber Plugs
Tapered Rubber Plugs are high-performance sealing and masking components made from either EPDM or Silicone, designed for use in demanding industrial applications. Their tapered shape allows for a snug, versatile fit across a range of hole sizes, making them ideal for powder coating, anodising, electroplating, and chemical sealing. EPDM plugs offer excellent chemical resistance and withstand temperatures up to 245°C, while Silicone versions endure up to 315°C, making them suitable for high-temperature environments. These plugs are reusable, durable, and available in various sizes and colours for easy identification.
Silicone Plugs With Handles
Silicone Plugs with Handles are high-temperature masking plugs designed for easy insertion and removal during finishing processes like powder coating, anodising, and shot blasting. Made from premium-grade silicone rubber, they withstand continuous heat up to 315°C. Their tapered design ensures a snug fit in both threaded and non-threaded holes, while the integrated handle allows for quick, tool-free removal—even in recessed or hard-to-reach areas. These plugs are reusable, chemically resistant, and ideal for industrial applications requiring speed, precision, and durability.
Barrel Plugs
Barrel Plugs, which are also know as Barrel Bungs, are durable, push-fit hole plugs made from tough LDPE plastic or food-grade silicone, designed to seal and protect openings in barrels and other containers. Featuring a flanged head for easy installation and removal, they offer a secure fit and reliable protection against ingress, contamination, and damage. Commonly used in industries such as food and beverage, manufacturing, and packaging, these plugs are available in a wide range of sizes—from 2mm to 85mm—and can be custom-made for specific applications.
Reversible Tapered Plugs
Reversible Tapered Plugs are versatile plastic components made from durable LDPE, designed to function as either a plug or a cap depending on your application needs. Their tapered body ensures a snug fit in a wide range of hole sizes (from 2mm to 300mm), while the flanged head allows for easy installation and removal. Resistant to acids, alkalis, moisture, and UV, these plugs are ideal for protecting components during transport, storage, or finishing processes. Available in red as standard, with custom sizes and colours on request.
Threaded Plugs
Threaded Plugs are durable plastic components designed to protect internal threads from damage, dirt, moisture, and corrosion during storage, transport, or processing. Commonly used in industries like manufacturing, hydraulics, and automotive, these plugs are available in BSP, UNF, and Metric thread types. Made from tough LDPE, they come in bright colours for easy identification and are simple to install or remove thanks to ergonomic designs. Ideal for sealing hydraulic ports, blanking unused threads, or safeguarding machinery.
Silicone Ribbed Plugs
Silicone Ribbed Plugs are flangeless, heat-resistant masking components designed for sealing and protecting holes during high-temperature processes like powder coating, anodising, and electroplating. Made from premium-grade silicone rubber, they withstand continuous exposure up to 315°C. Their ribbed design ensures a secure, flush fit in both threaded and non-threaded holes, preventing contamination and ensuring clean finishes. These reusable plugs are ideal for industrial applications requiring precision and durability.
Silicone Pull Plugs
Silicone Pull Plugs are high-temperature masking solutions designed for sealing and protecting through-holes during finishing processes like powder coating, anodising, and electroplating. Made from premium-grade silicone rubber, they withstand continuous heat exposure up to 315°C. Their parallel design ensures a snug, flush fit in both threaded and non-threaded holes, while the integrated pull tab allows for quick, tool-free removal—even in tight spaces. Reusable, durable, and resistant to chemicals, these plugs are ideal for industrial applications requiring precision and efficiency.
Threaded Sealing Plugs
Threaded Sealing Plugs are liquid-tight components designed to securely seal threaded holes in hydraulic, pneumatic, and fluid systems. Compatible with BSP, UNF, and Metric threads, they are made from durable HDPE and feature integrated nitrile O-rings for enhanced sealing performance. These plugs prevent leaks, contamination, and damage during manufacturing, transport, and storage. Easy to install and remove by hand or with tools, they are ideal for high-pressure applications across industries like automotive, oil and gas, and general engineering.
Where to Buy Bungs, Plugs and Stoppers
Vital Parts is a leading UK supplier of rubber bungs. As part of our standard product catalogue we offer a huge range of sizes. With bung sizing from 1.6mm maximum diameter all the way up to 127mm. We stock EPDM and Silicone rubber and specialise in masking bungs designed for high temperature applications like powdercoating.
Buy Rubber Plugs & Stoppers »Vital Parts: Custom Rubber Bung Design
As an experienced manufacturer of plastic and rubber components, Vital Parts is well positioned to assist customers with the design and creation of bespoke bungs. In a custom project, the design, material, shape, sizing and other features can be tailored to meet the specific needs of your application. This supplements our standard offering of Silicone and EPDM rubber bungs, and allows us to provide solutions to almost any customer requirement.
Custom Project Enquiry »Brands We've Supplied
We take immense pride in having supplied high-quality rubber bungs to a diverse range of companies, across many different sectors. Whether they are a distiller, engineers or a large-scale industrial operation, we work closely with each customer to ensure that we provide the right solution that meets their specific needs.
Can we help?
Please get in touch if you would like to speak with a member of our Sales Team regarding standard or custom parts
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