Rubber Stoppers

RubberMill produces rubber stoppers for the lab, commercial, medical, food and beverage, and industrial markets. Our standard grade stoppers are manufactured from a premium grade SBR black rubber compound. The 40 ± 5 durometer material is soft, pliable and long lasting. Solid, one-hole and two-hole stoppers are stocked for immediate shipment.

Please select from the following options and click for more information on our standard lab stopper sizes.

Solid Stoppers
One Hole Stoppers
Two Hole Stoppers


Lab Stopper Material Specifications

Compound SBR
Hardness/Durometer, Shore A 40 +/- 5
Temperature Range -40˚C to 70˚C
Specific Gravity 1.342
Tensile Strength 870 psi
Elongation 530%
Compression Set (22h at 70˚C) 38%
Heat Resistance (70h at 70˚C)

Hardness Change

Tensile Change

Elongation Change

+6 points


Properties are typical values. Final determination for suitability for use must be made by the customer. (05/16)

In addition to our standard stocked items, we manufacture custom stoppers in all durometers and compounds. Visit our Technical Data Section to learn more about different rubber compounds, durometer, and chemical resistance properties.

Tapered rubber stoppers are the most common configuration, but we can provide any shape plug, bung, or stopper you need for labware, bottles, boiler tubes, flasks, jars, test tubes or similar containers. Contact us to discuss your unique stopper needs.