Stopper chemistry
We all know how delicate and sensitive the chemical industry is. During the experiments, chemists use various elements, techniques, substances and additives to make their work simpler and, above all, safer. The supplements you can find in every lab are stoppers. Depending on the type of experiment, you can choose the ideal stopper for you.
Stopper chemistry is a very important aid when performing laboratory experiments. Use stoppers to prevent fluids and substances from leaking out of the test tube. Their main role is to protect the contents of the test tubes, prevent them from spilling, as well as change the contents during contact with air or external influences. In addition to their protective role, they also help a lot in easier mixing of substances and transfer from one test tube to another. They can also be used to hold sharp and sensitive tools in the laboratory such as needles. Their use is very wide and therefore the need for them is even greater.
Stopper chemistry materials can be varied. From cork to rubber, these plugs perform their function efficiently. The material of these plugs also depends on the type of test you perform. If it is a wine or food test, the use of a cork stopper is more common, but if it is a pharmaceutical experiment, rubber stoppers will be a much better choice for you. In both cases, they have a cyclic shape and are made to spread from the end to the very top. In this way they can meet many challenges and cover multiple openings of different shapes. Their size varies so you don’t have to worry about the dimension. For aesthetic reasons, they can also be found in different colors to help you with the selection of certain substances.
Stopper chemistry may contain holes as well. Stoppers without plugs will be predominantly used with a chemical that doesn’t create pressure in a closed container or test tube. However, in the case of more aggressive chemicals, our advice is to take a stopper with one or more holes to eliminate the possibility of gas formation in the bottle.
Stopper & Plug Size Catalog
Compare four stopper profiles and check the selected part dimensions against your opening and available depth. Each profile has its own drawing and dimension meanings.
Custom colors are available to your Pantone color code. Include the code in your inquiry.
RST T-Shaped Plugs
Match stem diameter A, flange diameter B, stem length C and flange thickness D. E refers to the underside recess; use the selected row and approved drawing to confirm the actual profile.

RSA Tapered Corks
Compare large-end diameter A, small-end diameter B and Height, in mm. The mating bore and required seating depth determine where the taper contacts the opening.

RSB Undercut Plugs
Compare neck diameter A, flange diameter B, flange-to-lip distance C and flange thickness D. Check panel thickness and rear clearance. E refers to the underside recess.

RSD T-Shaped Stoppers
Compare stem diameter A, flange diameter B, stem length C and head thickness D, in mm. Check the seating surface and available depth as well as the hole diameter.

Need a different fit? Share the opening dimensions, mating profile and intended use for a custom size.
Discuss Your RequirementsProduct specifications
- Product form
- Removable closure fitted inside an opening
- Application focus
- Laboratory vessels, test tubes, wine bottles and bottle necks. Size the part against the selected assembly.
- Dimensions to confirm
- Opening diameter, closure profile, insertion depth and exposed grip. Match these to laboratory vessels and test tubes.
- Contact conditions
- Air, wine, food ingredients and other gases: define concentration, temperature and contact time, then check compatibility with the chosen compound.
- Seating check
- Check the sealing contact around the opening and the force needed for insertion and removal.
Need a quote or a custom part?
Send your requirements, drawings or samples to discuss standard and custom silicone rubber parts.
Email us[email protected]