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
Hampton Research NATRIX 2 NO27 185ML
HR2-917-27/Natrix 2 #27 (G03), 185 ml - 0.02 M Magnesium chloride hexahydrate, 0.05 M Sodium cacodylate trihydrate pH 7.0, 15% v/v 2-Propanol, 0.001 M Hexammine cobalt(III) chloride, 0.001 M Spermine. Please note items from this supplier are non-returnable.
Hach Company Stopper, Polyethylene, Hollow, Size 2, 6/pk
Made of low-density polyethylene. Interchangeable with rubber stoppers. Safer and more economical than glass. Fits snugly. Excellent as sample cup for pH meters, flame photometers and automatic analyzers, or as a small beaker. 25-26 mm (1") high.
Chemglass Life Sciences Stopper, Flask Length, PTFE, Size 38
Stopper, Flask Length, PTFE, Size 38. PTFE stopper for use in flask length outer joints.
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 34/45 Stopper, Hollow
34/45 Stopper, Hollow. PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the glass outer joint. The 14/20 and 19/22 are solid, while the larger sizes are hollow.
Chemglass Life Sciences 45/50 Stopper, Hollow
45/50 Stopper, Hollow. PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the glass outer joint. The 14/20 and 19/22 are solid, while the larger sizes are hollow.
Chemglass Life Sciences 29/42 Stopper, Hollow
29/42 Stopper, Hollow. PTFE stopper has a Polypropylene extraction nut permitting easy removal of the stopper from the glass outer joint. The 14/20 and 19/22 are solid, while the larger sizes are hollow.
SCIMAC Safety Lab Stopper, Extraction Nut, Standard Taper, Hollow, PTFE, Joint: 19/38, Hollow
Safety Lab Stopper, Extraction Nut, Standard Taper, Hollow, PTFE, Joint: 19/38, Hollow, Height: 55mm. Full Length; Safety Lab Solid PTFE| Black Extraction Nut | Easy Removal from glass Joints | Boiling & Distilling Flasks |Autoclave Safe at 250˚F | Complies to ASTM E675
Ace Glass, Inc. Trap, stopper, vacuum, bent vertical tube, 34/45, 16mm inner& side tube OD
Trap, stopper, vacuum, bent vertical tube, 34/45, 16mm inner& side tube OD