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
Grainger Stopper Sz 13 58 mm BDia Black 0 PK5
The 16WC37 is a 16-inch diameter, 3-blade, cast aluminum propeller made by Sensenich Propeller Manufacturing Company. It has a pitch of 37 inches and is designed for experimental aircraft with engines from 65 to 85 horsepower. The propeller is manufactured from heat treated aluminum alloy for strength and durability. It has a standard 1-inch diameter propeller shaft hole and includes all mounting hardware. The 16WC37 provides efficient thrust while minimizing noise and vibration. With proper engine matching, it is an ideal propeller upgrade for many experimental amateur-built aircraft.
Chemglass Life Sciences 14/20 Stopper, Solid
14/20 Stopper, Solid. 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.
Chemglass Life Sciences Stopper, Flask Length, PTFE, Size 13
Stopper, Flask Length, PTFE, Size 13. PTFE stopper for use in flask length outer joints.
Cole-Parmer Indenti-Plug L800-B Plastic Foam Stopper, 14-20mm Openings, 1000/pk
Durable and reusable foam stoppers are an economical way to keep the contents of your containers secure. Open-cell foam has a uniform density, leaves no fibers like cotton, is breathable, nonabsorbent, chemcial resistant, heat tolerant, and retains shape after repeated use. Can also be used as a cleaner for pipettes, tubes, vials and precision tubing. Autoclavable.
Sigma Aldrich Fine Chemicals Biosciences Precision SealR rubber sep
The recommended choice for use with organic chemicals and solvents pressure applications and cannulation techniquesPrecision Seal septa are designed specifically for the rigorous requirements of chemical applications.Precision fit Precision Seal septa have a longer tapered plug that seats firmly inside the glass joint or tube providing a sealing surface that is 50 to 80% greater than standard sleeve stoppers. The inner seal design of Precision Seal septa minimizes chemical and solvent vapor migration up the joint to the sleeve which can swell leak or fail from exposure. The surface texture of the rubber is similar to that of a ground glass joint and resists movement once seated.Non-contaminating Precision Seal natural rubber is lower in solvent extractables 1.9% vs. standard sleeve stoppers 5-6%. Precision Seal rubber is higher in density to minimize the effects of solvent degradation. They are manufactured from a single certified lot for absolute consistency.Safet
Cole-Parmer Solid Color-Coded Silicone Stoppers, Standard Size 12, Yellow; 1/Bag
Silicone bubbles make these stoppers lightweightthey float on water. Withstand temperatures from 76 to 392>F (60 to 200>C). Stoppers are available in 14 color-coded sizes, given in both standard and Japanese size numbers. Softness and flexibility allow stoppers to fit a range of holes. Easily make openings for glassware fit your exact specifications with the optional cork borer set. 2 bags/case.
Enterprise Technology Solutions 20-Sheet Ez Squeeze Two-Hole P
20-Sheet Ez Squeeze Two-Hole Punch 9/32 Holes Black/silver
Chemglass Life Sciences Filtering Flask, 500 mL, PyrexPlus Coating, Tubulation, #7 Rubber Stopper
500 mL filtering flask with PyrexPlus protective coating, tubulation, and compatible rubber stopper. Made from borosilicate glass and graduated for approximate volumes, the flask is designed for vacuum filtration; the tubulation is left uncoated to permit easy tubing connection and the protective coating helps reduce glass shattering and contain spills.
- 500 mL capacity.
- Borosilicate glass construction.
- Protective PVC coating to reduce shattering and spills.
- Uncoated tubulation for easy tubing connection (10 mm outer diameter).
- Compatible with standard laboratory rubber stoppers.
- Autoclavable to 121 °C.
- Graduated for approximate volume.
- Pack quantity: case of 6.
Chemglass Life Sciences 24/40 PTFE Hollow Stopper, 1/4" NPT, Complete with Extraction Nut
24/40 PTFE Hollow Stopper, 1/4" NPT, Complete with Extraction Nut. PTFE stopper is similar to CG-3002-L but with the addition of one female NPT port in the center for connection of compression fittings or pressure/vacuum gauges. PTFE stopper has an extraction nut permitting easy removal of the stopper from the glass outer joint.
Cole-Parmer Solid Color-Coded Silicone Stoppers, Standard Size 8, Green; 10/Bag
Silicone bubbles make these stoppers lightweight—they float on water. Withstand temperatures from –76 to 392°>F (–60 to 200°>C). Stoppers are available in 14 color-coded sizes, given in both standard and Japanese size numbers. Softness and flexibility allow stoppers to fit a range of holes. Easily make openings for glassware fit your exact specifications with the optional cork borer set. 2 bg/cs.*
Chemglass Life Sciences Solid Rubber Stopper, #8, Black
Solid Rubber Stopper, #8, 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).
