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
Bellco Glass, Inc. Polypropylene Volumetric Flask W/Polypropylene Stopper,25mL Class B
Individually calibrated to deliver at 20C. Durable ring marks resilient wear. Supplied with standard ground polypropylene stopper. Certified Class B tolerance per DIN ISO 1042. Translucent with individual ring mark. Volume: 25ml Accuracy +/- ml: 0.06 Height: 115mm Stopper size: 10/19
Cole-Parmer Two-Hole Black Rubber Stoppers, Standard Size 00; 113/Pk
These two-hole black stoppers made with solid natural rubber stay pliable over a long period of time. Provide good tightness and adhesion, withstand laboratory conditions without hardening, and are ideal for use with nonaggressive or low concentration solutions. Each stopper has its size marked in raised figures. Low sulfur content. Withstand temperatures from –13 to 158°F (–25 to 70°C).
Hach Company Stopper-Two Hole
13 5 Two Hole stopper consists of a 13 5 SBR plug with 2 x 3/8 OD PP tube adapters for connection to a 10/20L vacuum rated PP carboy Ideal for use with Xenosep Solvent Recovery option 1pk
Accuflow Systems Saint-Gobain Versilic Stopper, Silicone, 8D, 20 mm
Peroxide-cured silicone stoppers designed for laboratory use. These chemically and biologically neutral closures are non-toxic, odorless, non-adherent, and resistant to aging. They withstand a wide temperature range and meet common laboratory standards, making them suitable for tissue culture and general laboratory containment.
- Material: Peroxide-cured silicone.
- Dimensions: Bottom 4 mm, Top 8 mm, Height 20 mm.
- Temperature range: -70°C to 250°C (-94°F to 482°F).
- Compliance: DIN 18271, FDA/BGA approvals.
- Pack quantity: 500 per pack.
- Properties: Chemically and biologically neutral, non-toxic, odorless, non-adherent, resistant to aging.
- Applications: Tissue culture, microbiology, hematology, food science, laboratory containers.
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 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.
Hach Company Stopper for 18mm Tube, 25/pk
Used in multiple tests as a stopper for viewing tubes and sample cells, and as a cap for AccuVac Ampules.
Chemglass Life Sciences Rubber Stopper, #11, Two Holes, Black
Rubber Stopper, #11, 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 (56mm), Bottom (48mm). Length: (25mm). Diameter of holes: (5mm).
Chemglass Life Sciences Solid Rubber Stopper, #3, Black
Solid Rubber Stopper, #3, 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 (24mm), Bottom (18mm). Length: (25mm).
Chemglass Life Sciences Rubber Stopper, #0, Two Holes, Black
Rubber Stopper, #0, 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 (17mm), Bottom (13mm). Length: (25mm). Diameter of holes: (3mm).
Chemglass Life Sciences Rubber Stopper, #7-1/2, One Hole, Black
Rubber Stopper, #7-1/2, 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 (39mm), Bottom (31mm). Length: (25mm). Diameter of hole: (5mm).