Working conditions
Identify temperature, contact fluids and repeated movement.

Custom manufacturing example · Silicone stopper rubber threaded hole plug silicone caps
CUSTOM RUBBER & SILICONE MANUFACTURING
A custom component for your assembly.
Define the mating surfaces, dimensions and working conditions. ETOL manufactures the part to the agreed design and material.
Share the part, its application and your estimated quantity.

Selected for the contact, temperature and movement
Define the visible surfaces and intended color
Develop holes, lips and walls around the mating parts
Match the attachment and installation method
A rubber threaded hole plug can close a threaded opening while retaining access for later assembly or servicing. Custom molding allows its engagement section and exposed end to follow the port geometry. The design should make the intended removal method clear and leave enough room to use it once surrounding components are installed.
Compare the complete thread form, not only the opening diameter. Pitch, usable depth, and any shoulder at the entrance influence how the plug reaches its seated position. An inaccessible recessed opening may require a different head shape from an exposed hole on a flat surface.
Start installation in line with the thread and stop if the part catches before engaging normally. Distorting the rubber with extra force can conceal a poor fit. Before reusing the plug, examine the engagement surface for cuts or stretched sections and remove loose contamination. Choose the rubber formulation for the temperature and substances around the opening. If the port becomes part of a pressurized system, its operating closure must be selected for that specific service.
Photos illustrate structure or material appearance only. A rubber threaded hole plug can close a threaded opening while retaining access for later assembly or servicing. ETOL directly manufactures custom-shaped silicone and rubber parts to your requirements.
FIND THE RIGHT FIT
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.
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.
| 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 |
70 tapered stopper sizes. Compare the large-end diameter A, small-end diameter B and overall height with the opening and intended insertion depth.
| 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 |
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.
| 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 |
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.
| 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.
Identify key dimensions, mating surfaces and quantity
Agree the compound and manufacturing approach
Review the fit and agreed requirements in the assembly
Manufacture and check against the approved requirements
Identify temperature, contact fluids and repeated movement.
Consider hardness together with wall thickness and support.
Check access, mating dimensions and the fitting sequence.
Yes. Show the receiving opening, contact surfaces and clearance limits. We can review the dimensions and retaining features around the intended fit.
Agree the critical dimensions, material, hardness, visible surfaces and sample requirements. Explain how the part is installed and which interfaces control its function.
A sample can help explain the structure. Compare it with the assembly because wear, swelling or compression may have changed its original dimensions.
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
Share the fit, operating conditions and quantity with our manufacturing team.