Rubber bung stopper
A rubber bung stopper is a remarkably efficient multipurpose stopper that has a tapered or conoid shape, designed to be used over a wide variety of holes and openings, instead of a single sized opening. This popular stopper solution is used for sealing off vessels, especially the ones containing compounds like petroleum, petrolatum, minerals, oils and fats, alongside almost every inorganic acid or base. They’re also used for anodizing, powder coating, sealing, or in printing industries because the rubber bung stoppers can withstand extreme fluctuations in temperatures, ranging from -60°C to a whopping +200°C, which makes them capable of absorbing the thermal energy that can be harmful to the vessel contents.
Aside from being temperature resistant, the rubber bung stoppers are durable. And it is their high durability that accounts for their ability to be re-used multiple times, which is particularly valuable for masking purposes. Coming to their dimensions, these bung stoppers are available in a wide range of sizes and it is advised to measure the diameter of the opening you wish to conceal or seal off first before selecting a rubber bung stopper. The bung stopper size to be selected should be slightly smaller than the size of your opening to achieve a decent, firm fit. If the size of the bung stopper is too big, it may slip off and render itself ineffective.
In order to support the insertion, the majority of such bung stoppers come with diagonal or tapered edges that slide right in until they attain a snug-fitting. A partially inserted rubber bung stopper is an excellent sealant that doesn’t let the contents of a beaker, jar, vessel, test tube, vial, pitcher, or pipette from being contaminated or exposed to air. Because of anti-spillage properties, these bung stoppers also find profound utilization in the forensic industry to seal and protect sensitive chemicals from oxidizing or leaking away.
All dimensions are in mm
Stopper & Plug Size Catalog
Compare four stopper profiles and check the selected part dimensions against your opening and available depth. Each profile has its own drawing and dimension meanings.
Custom colors are available to your Pantone color code. Include the code in your inquiry.
RST T-Shaped Plugs
Match stem diameter A, flange diameter B, stem length C and flange thickness D. E refers to the underside recess; use the selected row and approved drawing to confirm the actual profile.

RSA Tapered Corks
Compare large-end diameter A, small-end diameter B and Height, in mm. The mating bore and required seating depth determine where the taper contacts the opening.

RSB Undercut Plugs
Compare neck diameter A, flange diameter B, flange-to-lip distance C and flange thickness D. Check panel thickness and rear clearance. E refers to the underside recess.

RSD T-Shaped Stoppers
Compare stem diameter A, flange diameter B, stem length C and head thickness D, in mm. Check the seating surface and available depth as well as the hole diameter.

Need a different fit? Share the opening dimensions, mating profile and intended use for a custom size.
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