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
Hach Company Stopper, Neoprene, Solid, Size 6, 6/pk
Recommended where natural rubber would deteriorate or be attacked.
Foxx Life Sciences Borosil® Solid Penny Head Glass Stopper with Interchangeable Ground Joint 29/32, 20/CS
Borosil® Solid Penny Head Glass Stoppers are with Interchangeable Ground Joint and can be used with Volumetric Flask of 5645, 5647 families or for other suitable joints. Manufactured with low extractable quality grade USP Type I, 3.3 Borosilicate Glass confirming to ASTM E438 Class A requirements. Available in sizes of 7/16 to 55/54. 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.
Research Products International Corp Laboratory Grade Rubber Stoppers, Green Neoprene Rubber, Size #13, 4 per Package
Laboratory Grade Rubber Stoppers offered in a wide range of common sizes for most laboratory applications. Available in green neoprene rubber that is resistant to chemicals and ozone deterioration or standard black SBR rubber. Solid rubber stoppers are molded in the USA according to standard industry size specification. Packaged in approximately one pound packages.
Research Products International Corp Laboratory Grade Rubber Stopper, Black SBR Rubber, Size #5, 27 x 23 x 25mm, 28 per Package
Laboratory Grade Rubber Stoppers offered in a wide range of common sizes for most laboratory applications. Available standard black SBR rubber. Solid rubber stoppers are molded in the USA according to standard industry size specification. Packaged in approximately one pound packages.
Grainger Stopper Sz 8 33 mm BDia Black 0 PK12
The Grainger 16ZD72 is a 3M Speedglas Welding Helmet that features auto-darkening technology to protect the eyes and face during welding, cutting and grinding. It has a large viewing area, multiple adjustable settings like shade level and sensitivity, and comfortable padded headgear. The helmet provides versatility for different applications with grind, cut and weld modes. It meets industry safety standards. This auto-darkening welding helmet delivers reliable eye protection and visibility.
Chemglass Life Sciences Replacement Luer Stopper
Replacement Luer Stopper. Replacement luer stopper for CG-1158 caps.
Grainger Stopper Sz 13.5 62 mm BDia Black 0 PK3
The 16WC39 is a 16-ounce claw hammer by Estwing Manufacturing Company. It has a forged steel head and neck with a shock-reducing vinyl grip. The claw is curved for easier nail pulling. This American-made hammer is designed for general purpose use driving and pulling nails. It measures approximately 13.25 inches long.
Research Products International Corp Laboratory Grade Rubber Stoppers, Green Neoprene Rubber, Size #7, 37 x 30 x 25mm, 14 per Package
Laboratory Grade Rubber Stoppers offered in a wide range of common sizes for most laboratory applications. Available in green neoprene rubber that is resistant to chemicals and ozone deterioration or standard black SBR rubber. Solid rubber stoppers are molded in the USA according to standard industry size specification. Packaged in approximately one pound packages.
Chemglass Life Sciences #38 PTFE Stopper, Black Handle, Hollow
#38 PTFE Stopper, Black Handle, Hollow. Flask length PTFE stopper with color coded handle.
Sigma Aldrich Fine Chemicals Biosciences Precision SealR rubber sep
Engineered for a push on fit in NMR tubes and ampules. The unique design provides a penetration point for cannulation and a dual seal inside the tube and on the outer sleeve. Will not break delicate thin-wall tubing. Manufactured from one certified raw material formulation for absolute consistency in all sizes from lot to lot.Storage Note for Natural Rubber Septa Store septa in a closed bag out of sunlight to retard blooming which is the formation of a whitish film on the surface of the rubber. Blooming is a natural process and does not affect performance. Remove visible bloom by washing or wiping off before use.