Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
Chemglass Life Sciences Stopper, Pennyhead, Hollow, 10/18
Stopper, Pennyhead, Hollow, 10/18. Hollow stopper with closed bottom.
Chemglass Life Sciences PTFE/Silicone Stopper
Replacement PTFE/silicone stopper for Multi-Tier Reaction plates (CG191501, CG191502, CG191503).
Chemglass Life Sciences Stopper #22, Pennyhead, Flask Length, Solid
Stopper #22, Pennyhead, Flask Length, Solid. All sizes are solid with the exception of the #38 (CG-3018-08) which is hollow.
Chemglass Life Sciences Stopper, Flask Length, Flathead, Solid, Size 13
Stopper, Flask Length, Flathead, Solid, Size 13. Flathead design allows stopper to be inverted and placed on end thereby preventing contamination of the ground surface.
Foxx Life Sciences Borosil® Plastic Polypropylene Stopper for Volumetric Flasks with Interchangeable Joint 34/35, 50/CS
Borosil® Plastic Polypropylene Flat Head Stoppers are with Interchangeable Joint and can be used with Volumetric Flask of 5645, 5647 families or for other suitable joints. Polypropylene Available in sizes of 7/16 to 34/35. In collaboration with Borosil Glass Works, Foxx Life Sciences is proud to bring the outstanding quality of Borosil® Type 3.3 Borosilicate glassware to North America for the first time. Manufactured from the same USP Type I, Borosilicate glass that North American scientists have come to trust, Borosil® Laboratory Glassware offers unparalleled mechanical strength, clarity, and reliability at competitive prices. And thanks to a unique annealing process, Borosil® Glassware is stress-free and incredibly resistant to thermal shock.
Chemglass Life Sciences Vacuum Trap Stopper Only, 50/50
Vacuum Trap Stopper Only, 50/50. Replacement part for CG451504.
Chemglass Life Sciences Septum Stopper, Sleeve Type, for 5mm OD NMR Tubes, Red
Septum Stopper, Sleeve Type, for 5mm OD NMR Tubes, Red. Sleeve type stoppers with a hollow plugs and sleeve extensions that folds down over the neck of a vessel, tubing, etc. The diaphragm can be punctured with a syringe needle, re-sealing after the needle is withdrawn.
Chemglass Life Sciences Midget Impinger, Plain Top, Fritted Tube, Graduated, Stopper Only
Stopper Only. Replacement stopper for the CG182101 midget impinger.
Chemglass Life Sciences Foam Plug, fits 6-13mm Openings
Foam Plug, fits 6-13mm Openings. Identi-Plugs are for use with test tubes and flasks. They are reusable and leave no clinging fibers like cotton plugs. They provide a snug fit, yet permit free air flow. Plugs are ideal for use with Drosophila vials. They spring back to original shape after repeated use. Identi-Plugs can also be used as a cleaner for lab pipettes, tubes, vials, as well as industrial precision tubing. Plugs are approximately 1.75" long.
Zymo Research Corporation Neoprene Stopper, 1 pack
Neoprene Stopper to be used with the EZ-Vac Vacuum Manifold. For use with Zymo Research purification kits.
Sigma Aldrich Fine Chemicals Biosciences Precision SealR rubber sep
The recommended choice for use with organic chemicals and solvents pressure applications and cannulation techniquesPrecision Seal septa are designed specifically for the rigorous requirements of chemical applications.Precision fit Precision Seal septa have a longer tapered plug that seats firmly inside the glass joint or tube providing a sealing surface that is 50 to 80% greater than standard sleeve stoppers. The inner seal design of Precision Seal septa minimizes chemical and solvent vapor migration up the joint to the sleeve which can swell leak or fail from exposure. The surface texture of the rubber is similar to that of a ground glass joint and resists movement once seated.Non-contaminating Precision Seal natural rubber is lower in solvent extractables 1.9% vs. standard sleeve stoppers 5-6%. Precision Seal rubber is higher in density to minimize the effects of solvent degradation. They are manufactured from a single certified lot for absolute consistency.Safet
Chemglass Life Sciences Stopper, Grey Butyl Rubber, 20mm ASF
Stopper, Grey Butyl Rubber, 20mm ASF. For use with Headspace Vials.
Accuflow Systems Saint-Gobain Chemware Versilic Stoppers, Silicone, 0.709x0.946x1.182 in., 10/Pk.
Saint-Gobain Chemware Versilic Stoppers are silicone stoppers suitable for a range of laboratory uses, providing a reliable seal for vessels. This particular pack includes 10 stoppers with specific dimensions to fit various apparatus.
- Made from durable silicone material
- Dimensions of 0.709 x 0.946 x 1.182 in.
- Conveniently packaged as 10 per pack