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. Septa, red rubber, sized for 14/20 joints, pk/144
Septa, red rubber, sized for 14/20 joints, pk/144
Uline Rubber Pressure Pad For 24" Foot-Operated Impulse Sealer
Rubber Pressure Pad For 24IN Foot-Operated Impulse Sealer
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. #9 PTFE Stopper with Polypropylene Extraction
#9 standard taper PTFE stopper with polypropylene extraction nut for easy removal from outer joints.
Ace Glass, Inc. 55/50 PTFE Stopper with Polypropylene Extraction Nut, Solid
55/50 standard taper PTFE stopper with polypropylene extraction nut for easy removal from outer joints.
Grainger Stopper Sz 9 37 mm BDia Black 0 PK10
The Grainger 16ZD77 is a 3M Speedglas Welding Helmet that features auto-darkening technology to protect the eyes and face from sparks, spatter, and harmful UV/IR rays while welding. It has a large viewing area for increased visibility. The helmet provides shade levels from 5 to 13 adjustable via external knob. It has adjustable headgear for comfort and optimal fit. The helmet meets ANSI Z87.1 safety standards. The lithium battery powers up to 1500 hours of use. The Speedglas helmet provides reliable eye protection for welders.
Chemglass Life Sciences 45/50 PTFE Stopper, 3/4" NPT, Complete with Extraction Nut
45/50 PTFE Stopper, 3/4" NPT, Complete with Extraction Nut. PTFE stopper adapter is similar to CG-3002-L but with the addition of one female NPT port in the center. The optional PTFE compression fittings provide a convenient way to insert probes or connect PFA tubing or FEP tubing to reactors or flasks. PTFE stopper has an extraction nut permitting easy removal of the stopper from the glass outer joint.
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.
Grainger Stopper Sz 11 48 mm BDia Black 0 PK7
The Grainger 16VC08 is a 16-ounce aerosol can of CRC Brakleen non-chlorinated brake parts cleaner. It is a fast drying, non-flammable cleaner that removes oil, grease, brake fluid, and other contaminants from brake linings and drums. It contains no 1,1,1 trichloroethane, chlorofluorocarbons, or any ozone depleting substances. This brake parts cleaner features a 360-degree valve for convenient application at any angle.
Research Products International Corp Laboratory Grade Rubber Stoppers, Green Neoprene Rubber, Size #7, 37 x 30 x 25mm, 14 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.
Chemglass Life Sciences Solid Rubber Stopper, #7-1/2, Black
Solid Rubber Stopper, #7-1/2, 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 (39mm), Bottom (31mm). Length: (25mm).
Research Products International Corp Laboratory Grade Rubber Stoppers, Green Neoprene Rubber, Size #11, 6 per Pack
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.