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
Research Products International Corp Laboratory Grade Rubber Stoppers, Green Neoprene Rubber, Size #8, 41 x 33 x 25mm, 12 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.
Uline Rubber Pressure Pad For 24" Foot-Operated Impulse Sealer
Rubber Pressure Pad For 24IN Foot-Operated Impulse Sealer
Foxx Life Sciences Borosil® Amber Solid Penny Head Glass Stopper with Interchangeable Ground Joint 24/29, 20/CS
Borosil® Amber 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. Amber blocks 300nm to 500nm. 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 Stopper, Pennyhead, Hollow, 10/18
Stopper, Pennyhead, Hollow, 10/18. Hollow stopper with closed bottom.
Chemglass Life Sciences #19 PTFE Stopper, Green Handle
#19 PTFE Stopper, Green Handle. Flask length PTFE stopper with color coded handle.
Chemglass Life Sciences Septum Stopper, Sleeve Type, For 29/26-29/42 Outer Joints, Red
Solid Rubber Stopper, #00, Black. These stoppers are suitable for practically all general laboratory uses. Composition ensures resiliency and pliability over a long period and withstands laboratory conditions without hardening. The dimensions are in accordance with specifications established by the N.B.S. and are low in free sulfur (1/2%). Autoclavable at 250°F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Diameter: Top (15mm), Bottom (10mm). Length: (25mm).
Ace Glass, Inc. Stopper, cone, 37mm OD top, 22mm OD bottom, black neoprene, pk12
22mm to 37mm OD black neoprene nested ring pluro stoppers. Will give a vacuum tight fit for all openings within its size range. Suitable for applications from -40 to 150 degrees F.
Chemglass Life Sciences Stopper, Pennyhead, Hollow, 29/42
Stopper, Pennyhead, Hollow, 29/42. Hollow stopper with closed bottom.
Ace Glass, Inc. #11 Ace-Thred solid PTFE plug, 7855-708 FETFE O-ring front seal
#11 Ace-Thred solid PTFE plug with front seal o-ring, for sealing column ends. Permits preparation and storage of columns. Supplied with size -012 FETFE o-ring.
Chemglass Life Sciences Stopper, Hex Head, Hollow, 14/20
Stopper, Hex Head, Hollow, 14/20. Hexagonal shaped head of stopper prevents it from rolling off of the bench top. Flat surface will also permit stopper to be inverted and placed on end, thereby preventing possible contamination of ground surface.
Chemglass Life Sciences Stopper, Pennyhead, Solid, 14/20
Stopper, Pennyhead, Solid, 14/20. Solid stopper with closed bottom.
Chemglass Life Sciences Stopper, Pennyhead, Hollow, 14/35
Stopper, Pennyhead, Hollow, 14/35. Hollow stopper with closed bottom.
Chemglass Life Sciences Stopper, # 27, Polyethylene
Stopper, # 27, Polyethylene. These blue and white stoppers are made with closed bottoms, of linear high-density polyethylene to conform to stopper dimensions. The three unit rings on the base provide an efficient seal. The improved design fully protects the neck in the event of accidental tipping. These stoppers may be used in place of the conventional flask stoppers.
Cole-Parmer Twistit black rubber stopper assortment pack
Use these versatile Twistit stoppers as either a solid, one-hole, two-hole, or three-hole stopper. Simply twist off a bottom seal to open a hole. The soft resilient natural rubber stays pliable over a long period and withstands laboratory conditions without hardening. Stoppers retain resiliency even after repeated autoclaving. Each stopper has its size in raised figures on top. Available in black or white rubber. Autoclavable.