Tapered rubber stoppers
Tapered rubber stoppers seat inside a container neck using their changing diameter. The taper allows the contact position to move as the stopper is inserted, but each design still has a limited fitting range. Match that range to the opening and the insertion depth required by the vessel.
A stopper for a vial or test tube needs enough contact to remain seated and an accessible end for removal. Surface condition and dimensional tolerances affect the fit. Check the assembled closure for the leakage limit required by the application, especially when it contains a volatile liquid or gas.
Chemical resistance and permeation depend on the selected rubber, the contents, temperature and exposure time. No general tapered-stopper description establishes resistance to every chemical. For food or laboratory use, identify the intended contact and cleaning conditions before selecting the compound.
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.
Discuss Your RequirementsProduct specifications
- Product form
- Tapered rubber stopper within a defined vessel-fitting range.
- Seating geometry
- Match opening diameter and intended insertion depth to the taper.
- Handling
- Check accessible removal area and retention during use.
- Sealing requirement
- Define the acceptable leakage for the assembled closure.
- Material limits
- Evaluate chemical compatibility and permeation for the contents, temperature and duration.
Need a quote or a custom part?
Send your requirements, drawings or samples to discuss standard and custom silicone rubber parts.
Email us[email protected]