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
SIGMA ALDRICH FINE CHEMICALS BIOSCIENCES SLEEVE STOPPER SEPTA FKM
NC3257959 SLEEVE STOPPER SEPTA FKM
DATWYLER PHARMA PACKAGING USA INC V9024 RFS STOPPERS 16000 PCS
NC3856757 V9024 RFS STOPPERS 16000 PCS
Bellco Glass, Inc. KAP-UTS/Blue,16mm
Manufactured from non-toxic autoclavable polypropylene. Ideal for culture tubes and flasks with DeLong style neck and access ports. Same evaporation and sterility characteristics as stainless steel closures. Molded pressure fins for firm grip. There are seven colors and six sizes form 13mm to 38mm. MADE IN THE USA. Case quantity 1000, Color Blue, 16mm
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.
Grainger Stopper Sz 3 18 mm BDia Black 0 PK40
The Grainger Approved Stopper is a rubber stopper designed to seal openings in laboratory glassware. It is made of black rubber and has a diameter of 7/16 inches. The stopper features a solid top to prevent spillage and a tapered design for easy insertion and removal. It creates an airtight seal and can withstand temperatures up to 250°F. The stopper is sold individually. It is an economical option for sealing flasks, test tubes, and other glass containers in chemistry labs.
Chemglass Life Sciences Rubber Stopper, #5-1/2, One Hole, Black
Rubber Stopper, #5-1/2, One Hole, 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 250F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Diameter: Top (28mm), Bottom (24mm). Length: (25mm). Diameter of hole: (5mm).
Chemglass Life Sciences Rubber Stopper, #6, Two Holes, Black
Rubber Stopper, #6, Two Holes, Black. Similar to CG-3026 and CG-3027 except with two holes. 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 250F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Diameter: Top (32mm), Bottom (26mm). Length: (25mm). Diameter of holes: (5mm).
Foxx Life Sciences Borosil® Amber Solid Penny Head Glass Stopper with Interchangeable Ground Joint 12/21, 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.