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
Research Products International Corp Laboratory Grade Rubber Stoppers, Green Neoprene Rubber, Size #10, 50 x 42 x 25mm, 8 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.
West Pharmaceutical Services Inc WEST PHARMACEUTICAL SERVICES INC
NC3946553 20MM-DAIKYO-D-SIGMA-CHLOROBUTY
Cayman Chemical 96-Wel SolId Plateblack 1ea
An uncoated flat-bottom 96 well plate for use in fluorescence or chemiluminescent assays.
Grainger Rubber Rim Hole Plug 5/8 Rim
The Haltec Rubber Rim Hole Plug is a rubber plug designed to seal holes in wheel rims. It has a tapered design to fit different hole sizes and is made of durable rubber that resists cracking, weathering, and aging. The plugs come in a pack of 100 and fit hole sizes ranging from 5/16 inch to 3/4 inch. They can seal spoke holes, valve stem holes, and other rim holes to prevent air leaks. The plugs are easy to install by simply tapping into the hole with a hammer. Overall, the Haltec Rubber Rim Hole Plugs provide an effective and affordable way to seal holes in wheel rims.
Chemglass Life Sciences Rubber Stopper, #12, One Hole, Black
Rubber Stopper, #12, One Hole, Black, 3/PK
Hach Company STOPPER, PENNY HEAD
Replacement ground glass stopper. For use with the Cold Vapor Mercury Test, 14/20 standard taper joint. 1/pk
Hach Company Silicone Stopper, with 9.5 mm Hole, #8
For Use with the Xenosep Oil and Grease Apparatus. 1/pk
Hach Company Stopper, Rubber, One Hole, Size 8, 1/pk
#8 Black SBR stopper, complete with one 7/8 inch diameter drilled center hole. 1/pk.
Chemglass Life Sciences Twist It Stoppers, White, Assortment Pack of 33
Twist It Stoppers, White, Assortment Pack of 33. Three twist-off seals permit easy conversion from a solid to a one, two, or three-hole stopper. Soft, resilient, natural rubber demonstrates exceptional aging characteristics and withstands repeated autoclaving. Autoclavable at 250F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Note: #3 & #4 only have two holes. The Assortment Pack Consists of the Following Stoppers: 9 each Size # 3, 8 each Size # 4, 6 each Size # 5, 4 each Size # 6, 2 each Size # 7, 2 each Size # 8, 1 each Size # 9, 1 each Size # 10.
Chemglass Life Sciences Rubber Stopper, #8-1/2, Two Holes, Black
Rubber Stopper, #8-1/2, 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 (43mm), Bottom (36mm). Length: (25mm). Diameter of holes: (5mm).