Professional Rubber Stoppers And Rubber Plugs Manufacturer

How to Order Rubber Stoppers

• Step 1. Email us or use the inquiry form to share your plug sizes and any requirements for oil resistance, high temperature resistance or UV resistance.
• Step 2. We arrange samples of rubber plugs for you to check against your requirements.
• Step 3. Once you approve the sample, we arrange mass production to the agreed specification. Production typically takes about 5–10 days; confirm the schedule for your order.
• Step 4. We arrange delivery to your address by DHL, UPS, FedEx or sea freight, as agreed for your order.

Explore more than 3,000 types of rubber hole plugs and check our rubber stopper sizes. If you cannot find a suitable fit, ask about custom colors, materials and dimensions.

What Are Rubber Stoppers, Plugs, Corks and Caps?

A rubber stopper seals an opening to help isolate and protect its contents. Rubber plugs are used in automotive, machinery and electronics applications, while silicone plugs are also considered for medical and cosmetic products where the selected material meets the application requirements. If you need rubber plugs to fill holes, start with the opening dimensions and the type of seal or protection required. 

Rubber parts appear throughout everyday equipment and furniture. A rubber stopper, rubber plug, rubber cork or rubber cap can seal an opening, cover an exposed end or protect a contact point. The right choice depends on how the part fits and what it needs to do.

In laboratories, a rubber stopper seals the opening of a flask, test tube or other glassware. Also called a rubber bung plug, it helps contain liquids or gases when correctly sized and selected for the operating conditions. Check the fit, chemical compatibility and intended handling before use.

Depending on the material and design, a rubber stopper can offer:

• Durability suited to the application.
• A close fit against the sealing surface.
• Temperature resistance matched to the selected compound.
• A flexible shape that conforms to a suitable opening.
• A barrier that helps protect a test-tube sample from contamination.

A rubber cork works much like a rubber stopper. It is used in electrical appliances, gas systems, vehicles, industrial equipment, transport, railways and construction. When matched to the application, its useful features include:

• Flexibility and compressibility for a close fit.
• Material options for different operating temperatures.
• Resistance to wear and tearing, depending on the compound and use.
• Lightweight construction.

A small rubber stopper can be made from natural or synthetic rubber. Rubber stoppers and corks seal container openings, while a rubber plug can also close a hole to help keep liquids or gases out. These parts are used in gas, chemical, shipping and construction applications. Features to consider include:

• Weather, UV and ozone resistance appropriate to the selected material.
• Compound options for the required service temperature.
• Push-fit installation without a threaded connection, where the design allows.
• Straightforward installation for a correctly sized part.
• Resistance to cracking and tearing to help maintain the fit over time.

A rubber end cap covers the outside of a pipe or component end; a rubber body plug fits into an opening. Rubber endcaps help keep out dirt, dust, moisture and other contaminants during storage, manufacturing, transportation and assembly. Choose rubber caps or plugs according to the surface to be covered and the fit required.

Common Applications for Rubber Stoppers, Plugs and Caps

A rubber stopper, rubber cork, rubber plug and rubber cap may serve related purposes, but their fit and intended use differ. Commercial, industrial, chemical and scientific applications each call for a suitable shape, material and sealing method.

Commercial Applications

Commercial applications include rubber caps used as rubber feet on chairs and furniture, and rubber stoppers used as bumpers or door stoppers. These parts help cushion contact and protect surfaces. Rubber plugs also close openings in plumbing and other equipment; the fit and material must suit the intended service.

Industrial Applications

In manufacturing, a rubber stopper or rubber cork may seal a process or storage container. The rubber plug needs to match the opening, contents, temperature and pressure. Chemical resistance and tear resistance depend on the compound, so share these conditions when selecting the part. 

Chemical Applications

Chemical containers need a seal that is compatible with their contents. A rubber plug can help limit leaks and contact with air, but no compound suits every chemical. Specify the substance, concentration, temperature and handling conditions so the material and sealing arrangement can be reviewed.

Scientific Applications

Scientific applications include rubber cork seals for test tubes, flasks and laboratory glassware. Tube stoppers help contain a sample and reduce contamination during handling. A rubber stopper with hole can accommodate a thermometer or other instrument; one-hole and two-hole versions need to be sized for both the container and the inserted equipment.

How to Fit Rubber Stoppers and Caps

Select a rubber stopper for the opening and operating conditions, then follow the equipment instructions. The following steps outline the fitting process.

Step 1: Check the opening dimensions and choose a matching rubber plug. For a tapered rubber cork, the opening should fall within the specified diameter range so the stopper seats securely without excessive force.

Step 2: Choose a solid rubber plug or rubber hole plug according to whether the assembly needs a closed seal or a passage for tubing or instruments.

Step 3: Clean the mating surfaces. If lubrication is required, use only a lubricant approved for the stopper, container and contents, and avoid contaminating the sample.

Step 4: Insert the rubber stopper gently and check that it is seated correctly. Stop if excessive force is needed, especially with glass containers.

Rubber stoppers, plugs and corks fit inside an opening. Rubber caps fit over the outside of a component, so check the external dimensions before fitting them:

Step 1: Remove dust and chemical residue from the external mating surface using an appropriate cleaning method.

Step 2: Check the cap size and any installation requirements. Use lubricant only if it is approved for the material and application.

Step 3: Press the cap into place and check that it is fully seated.

Shapes and Types of Rubber Stoppers, Plugs and Caps

Rubber stopper and rubber cork designs often have a tapered body. Common configurations include:

• Solid stopper: A rubber stopper without a through-hole, used to close containers. This rubber plug design is also used in wineries and breweries when the material is suitable for the intended contact.
• One-hole stopper: A rubber cork with a passage for a thermometer, tube or other instrument. Select the body size and hole diameter to suit the laboratory setup.
• Two-hole stopper: A laboratory rubber cork with two passages for instruments or tubing. Sealing depends on the fit at each opening.
• Tapered caps and plugs: A tapered rubber plug accommodates an opening within its specified diameter range. Select the diameter and insertion depth for the required fit.
• Push-fit caps: Rubber caps that fit over a component without separate fasteners. Various shapes and sizes are used for storage and transportation.
• Rubber bolt caps and plugs: Screw end caps and protective plugs used to cover exposed fasteners or fittings, including hydraulic hose fittings.
• Vinyl end caps: Flexible caps that stretch over a component end and can be removed when access is needed.
• Pipe protection caps: Round rubber end caps for pipe ends help protect against damage and contamination. Rubber end caps for round tubing are available in different diameters to match the outside of the tube.
• Parallel protection plugs: A rubber plug with a straight-sided profile that helps keep dirt and moisture out of a matching opening.

Materials for Rubber Stoppers, Plugs and Caps

Common material options include the following. Confirm the compound against your temperature, chemical and mechanical requirements.

• Natural rubber: Used where flexibility and abrasion resistance matter. Temperature suitability depends on the compound and exposure duration; oil, gasoline, ozone and sunlight also affect material selection.
• Silicone: An option for flexible rubber stopper designs and applications with specific temperature requirements. Confirm the grade and its tested limits.
• Styrene-Butadiene Rubber (SBR): An option for rubber caps and general-purpose parts. Check suitability for the fluid, pressure and temperature involved.
• EPDM: Often considered for weather-exposed parts. Confirm compatibility with the chemicals and temperatures in your application.
• Neoprene: A general-purpose option for indoor and outdoor parts. Check the compound's resistance to the actual chemicals and weather conditions.
• Nitrile rubber (NBR): An option for rubber plugs used in automotive and machinery applications, subject to the operating conditions.

Compare the rubber stopper sizes in the product tables to find a rubber plug for your opening. We also make special-shaped stoppers to your drawing. Depending on the design, samples may be available in as little as 48 hours; ask us to confirm pricing and timing for your project.