Working conditions
Identify temperature, contact fluids and repeated movement.
Custom manufacturing example · Silicone bung silicone rubber stopper for glass test tube
CUSTOM RUBBER & SILICONE MANUFACTURING
Silicone bung silicone rubber stopper for glass test tube
A custom component for your assembly.
Define the mating surfaces, dimensions and working conditions. ETOL manufactures the part to the agreed design and material.
- Factory direct
- Made to order
- Drawing & sample support
Share the part, its application and your estimated quantity.
Customize the fit, material and finish
Material & hardness
Selected for the contact, temperature and movement
Color & finish
Define the visible surfaces and intended color
Shape & dimensions
Develop holes, lips and walls around the mating parts
Mounting & fit
Match the attachment and installation method
Product Overview
Silicone test tube stoppers should fit the actual glass tube mouth and the intended insertion depth. Custom molding allows the stopper shape, hardness, and exposed handling area to be developed around that opening. The relationship between the glass rim and the rubber contact region is more useful than matching only an approximate tube size.
Check the tube mouth for damage before fitting. A chipped or cracked rim should not be loaded by forcing in a stopper. Align the closure with the opening and use controlled pressure so that the stopper enters squarely. Enough material should remain accessible for the intended removal method.
Material selection depends on the tube contents and the procedures used with it. Choose the silicone formulation for the actual substances and temperature conditions, including cleaning between uses. This closure should not be assumed to make an ordinary glass tube suitable for pressure or vacuum service.
Keep the stopper's contact surface clean and avoid placing it on a contaminated bench while the tube is open. Before reuse, check for particles, cuts, or persistent deformation that could interfere with seating. Store matching stoppers where their intended tube sizes remain easy to distinguish.
- Material options
- Custom silicone compound; formulation and geometry developed together.
- Hardness selection
- Silicone options: 20–80 Shore A. A silicone rubber stopper for a glass test tube should fit the actual tube mouth and the intended insertion depth.
- Custom geometry
- Custom molding allows the stopper shape, hardness, and exposed handling area to be developed around that opening.
- Fit evaluation
- Check the tube mouth for damage before fitting.
- Color & OEM
- Custom colors; OEM identification positioned outside closure contact surfaces.
Photos illustrate structure or material appearance only. A silicone rubber stopper for a glass test tube should fit the actual tube mouth and the intended insertion depth. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.
FIND THE RIGHT FIT
Stopper & Plug Size Catalog
Choose a blind-hole, tapered, undercut or solid T-shaped profile, then compare its dimensions with the opening and available seating depth. Each profile has its own drawing and dimension meanings.
RST Blind-Hole Plugs
155 T-shaped plug sizes. Match shank diameter A, head diameter B, shank length C and head thickness D. E is the bottom blind-hole diameter; E = 0 indicates a solid shank.
DIMENSION GUIDE
PRODUCT APPEARANCE
| P/N | A | B | C | D | E | Unit |
|---|---|---|---|---|---|---|
| RST2.5-5.5-5.3 | 2.5 | 5.5 | 5.3 | 2 | 0 | mm |
| RST2.7-5.5-5 | 2.7 | 5.5 | 5 | 2 | 0 | mm |
| RST3-4.3-4.5 | 3 | 4.3 | 4.5 | 0.8 | 0 | mm |
| RST3-7-7 | 3 | 7 | 7 | 2.2 | 0 | mm |
| RST3.3-6.5-6 | 3.3 | 6.5 | 6 | 1.5 | 0 | mm |
| RST3.5-6.5-6 | 3.5 | 6.5 | 6 | 2 | 0 | mm |
| RST3.8-7-10.5 | 3.8 | 7 | 10.5 | 1.5 | 0 | mm |
| RST3.8-7-7 | 3.8 | 7 | 7 | 1.5 | 0 | mm |
| RST3.8-7-6 | 3.8 | 7 | 6 | 1.5 | 0 | mm |
| RST4-7.5-6 | 4 | 7.5 | 6 | 2 | 0 | mm |
| RST4-9.5-7 | 4 | 9.5 | 7 | 2.5 | 0 | mm |
| RST4.3-8-6 | 4.3 | 8 | 6 | 1.5 | 0 | mm |
| RST4.5-7.5-6 | 4.5 | 7.5 | 6 | 2 | 0 | mm |
| RST4.8-6.8-3.6 | 4.8 | 6.8 | 3.6 | 0.9 | 0 | mm |
| RST4.8-9-7 | 4.8 | 9 | 7 | 1.5 | 0 | mm |
RSA Tapered Stoppers
70 tapered stopper sizes. Compare the large-end diameter A, small-end diameter B and overall height with the opening and intended insertion depth.
DIMENSION GUIDE
PRODUCT APPEARANCE
| P/N | A | B | Height | Color | Material | Unit |
|---|---|---|---|---|---|---|
| RSA1.6-0.4-15.9 | 1.6 | 0.4 | 15.9 | Transparent | Silicone | mm |
| RSA2-0.5-19.1 | 2 | 0.5 | 19.1 | Transparent | Silicone | mm |
| RSA3.2-0.8-15.9 | 3.2 | 0.8 | 15.9 | Transparent | Silicone | mm |
| RSA3.2-1.6-15.9 | 3.2 | 1.6 | 15.9 | Transparent | Silicone | mm |
| RSA4.8-1.6-15.9 | 4.8 | 1.6 | 15.9 | Transparent | Silicone | mm |
| RSA4.8-1.6-19.1 | 4.8 | 1.6 | 19.1 | Transparent | Silicone | mm |
| RSA5.5-1.2-38.1 | 5.5 | 1.2 | 38.1 | Transparent | Silicone | mm |
| RSA6.4-3.2-19.1 | 6.4 | 3.2 | 19.1 | Transparent | Silicone | mm |
| RSA6.4-3.2-25.4 | 6.4 | 3.2 | 25.4 | Transparent | Silicone | mm |
| RSA8.7-4.8-15.9 | 8.7 | 4.8 | 15.9 | Transparent | Silicone | mm |
| RSA8.7-4.8-25.4 | 8.7 | 4.8 | 25.4 | Transparent | Silicone | mm |
| RSA9.2-6.2-12.8 | 9.2 | 6.2 | 12.8 | Transparent | Silicone | mm |
| RSA9.5-6.5-18.5 | 9.5 | 6.5 | 18.5 | Transparent | Silicone | mm |
| RSA11-8.5-17.5 | 11 | 8.5 | 17.5 | Transparent | Silicone | mm |
| RSA11.5-6.5-25 | 11.5 | 6.5 | 25 | Transparent | Silicone | mm |
RSB Undercut Plugs
50 undercut plug sizes with a retaining lip. A is the neck diameter and C is the distance from the underside of the head to the upper face of the lip. E = 0 indicates a solid shank.
DIMENSION GUIDE
PRODUCT APPEARANCE
| P/N | A | B | C | D | E | Unit |
|---|---|---|---|---|---|---|
| RSB2.5-6-3 | 2.5 | 6 | 3 | 1.5 | 0 | mm |
| RSB3-7-3 | 3 | 7 | 3 | 2 | 0 | mm |
| RSB3.5-7.5-3 | 3.5 | 7.5 | 3 | 2 | 0 | mm |
| RSB3.6-7.5-6 | 3.6 | 7.5 | 6 | 2 | 0 | mm |
| RSB4-8-3 | 4 | 8 | 3 | 2 | 0 | mm |
| RSB4.5-8.5-3 | 4.5 | 8.5 | 3 | 2 | 2 | mm |
| RSB5-9-3 | 5 | 9 | 3 | 2 | 2.5 | mm |
| RSB5.5-9.5-3 | 5.5 | 9.5 | 3 | 2 | 3 | mm |
| RSB6-10-4 | 6 | 10 | 4 | 2 | 3.5 | mm |
| RSB6.5-10.5-4 | 6.5 | 10.5 | 4 | 2 | 4 | mm |
| RSB6.5-12-8 | 6.5 | 12 | 8 | 2 | 0 | mm |
| RSB6.7-8.7-5.3 | 6.7 | 8.7 | 5.3 | 1.3 | 4.1 | mm |
| RSB7-11-4 | 7 | 11 | 4 | 2 | 4.5 | mm |
| RSB7.5-11.5-4 | 7.5 | 11.5 | 4 | 2 | 5 | mm |
| RSB8-12-4 | 8 | 12 | 4 | 2 | 5.5 | mm |
RSD T-Shaped Stoppers
30 solid T-shaped stopper sizes. Compare shank diameter A and length C with the opening; head diameter B and thickness D define the top flange.
DIMENSION GUIDE
PRODUCT APPEARANCE
| P/N | A | B | C | D | Color | Material | Unit |
|---|---|---|---|---|---|---|---|
| RSD2.7-5.5-5 | 2.7 | 5.5 | 5 | 2 | Black, White | Silicone | mm |
| RSD3-7-7 | 3 | 7 | 7 | 2.2 | Black, White | Silicone | mm |
| RSD3.3-6.5-6 | 3.3 | 6.5 | 6 | 1.5 | Black, White | Silicone | mm |
| RSD3.5-6.5-6 | 3.5 | 6.5 | 6 | 2 | Black, White | Silicone | mm |
| RSD3.8-7-6 | 3.8 | 7 | 6 | 1.5 | Black, White | Silicone | mm |
| RSD4-9.5-7 | 4 | 9.5 | 7 | 2.5 | Black, White | Silicone | mm |
| RSD4.3-8-6 | 4.3 | 8 | 6 | 1.5 | Black, White | Silicone | mm |
| RSD4.5-7.5-6 | 4.5 | 7.5 | 6 | 2 | Black, White | Silicone | mm |
| RSD4.8-9-7 | 4.8 | 9 | 7 | 1.5 | Black, White | Silicone | mm |
| RSD5-12-8 | 5 | 12 | 8 | 2.8 | Black, White | Silicone | mm |
| RSD5.3-9.5-7 | 5.3 | 9.5 | 7 | 1.5 | Black, White | Silicone | mm |
| RSD5.5-8.5-7 | 5.5 | 8.5 | 7 | 2 | Black, White | Silicone | mm |
| RSD5.8-10-8 | 5.8 | 10 | 8 | 2 | Black, White | Silicone | mm |
| RSD6-13-8 | 6 | 13 | 8 | 3.5 | Black, White | Silicone | mm |
| RSD6.3-10.5-8 | 6.3 | 10.5 | 8 | 2 | Black, White | Silicone | mm |
Need a different fit? Share the opening dimensions, mating profile and intended use for a custom size.
From part requirements to production
01
Define the part
Identify key dimensions, mating surfaces and quantity
02
Review material & tooling
Agree the compound and manufacturing approach
03
Evaluate the sample
Review the fit and agreed requirements in the assembly
04
Produce & inspect
Manufacture and check against the approved requirements
Review the intended assembly
Material and structure
Consider hardness together with wall thickness and support.
Installation
Check access, mating dimensions and the fitting sequence.
Ordering this custom component
Can the shape be adjusted to my mating parts?
Yes. Show the receiving opening, contact surfaces and clearance limits. We can review the dimensions and retaining features around the intended fit.
Which details should be agreed before tooling?
Agree the critical dimensions, material, hardness, visible surfaces and sample requirements. Explain how the part is installed and which interfaces control its function.
Can a sample help define the replacement?
A sample can help explain the structure. Compare it with the assembly because wear, swelling or compression may have changed its original dimensions.
How is the quotation for this part determined?
The material, part geometry, tooling, quantity and finishing affect the quotation. Include the intended batch size and delivery destination when describing your requirements.
DISCUSS THIS COMPONENT
Describe the part you need.
Share the fit, operating conditions and quantity with our manufacturing team.
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