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
Chemglass Life Sciences Replacement Luer Stopper
Replacement Luer Stopper. Replacement luer stopper for CG-1158 caps.
Grainger Stopper Sz 15 83 mm BDia Black 0
The 16WC61 is a 16 oz. 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 16 inches long and weighs 1.5 pounds. The head measures 4 inches across.
Electron Microscopy Sciences Lyophilization Three Leg Stoppers Gray, 13 mm I.D., 20 mm O.D.
Manufactured from the highest quality raw materials. Fits mouth with:
I.D.: 13 mm
O.D.: 20 mm
Material: Gray holobutyl/50
MSC Nylon Cap Nut, 5/16-18 Thread, Made in USA
This nylon cap nut is designed for fastening applications where a protective and insulating cover over exposed bolt threads is required. It features a 5/16-18 thread for secure attachment.
- Constructed from durable nylon.
- Features a 5/16-18 thread size.
- Provided in a pack of 15.
- Manufactured in the USA.
Ace Glass, Inc. #80 solid PTFE plug, 7855-766 FETFE O-ring back seal
#80 solid PTFE plug, 7855-766 FETFE O-ring back seal
Ace Glass, Inc. #32 PTFE Stopper with Polypropylene Extraction
#32 standard taper PTFE stopper with polypropylene extraction nut for easy removal from outer joints.