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
Ace Glass, Inc. Trap, stopper, vacuum, 50/50, 30mm inner & side tube OD
Trap, stopper, vacuum, 50/50, 30mm inner & side tube OD
Ace Glass, Inc. TRAP STOPPER VACUUM 29/32 TRAP STOPPER VACUUM 29/32
Stopper with 29/32 joint for use with a vacuum trap.
Chemglass Life Sciences Stopper, Pennyhead, Hollow, 29/42
Stopper, Pennyhead, Hollow, 29/42. Hollow stopper with closed bottom.
Chemglass Life Sciences Stopper, Pennyhead, Hollow, 10/18
Stopper, Pennyhead, Hollow, 10/18. Hollow stopper with closed bottom.
Chemglass Life Sciences Stopper, Pennyhead, Solid, 14/20
Stopper, Pennyhead, Solid, 14/20. Solid stopper with closed bottom.
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.