Working conditions
Identify temperature, contact fluids and repeated movement.

Custom manufacturing example · 28mm oil proof rubber plugs/(NBR) rubber sealing stoppers
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
NBR rubber sealing stoppers in a 28 mm size configuration close a defined opening with a molded profile. The nominal reference should be coordinated with the body, head, and seating features required by the receiving part. A complete dimensional match is needed in addition to the material choice.
For oil exposed use, establish the specific oil, temperature, and duration of contact. Include any cleaning or maintenance substances that reach the stopper. The selected NBR formulation should be assessed for those conditions rather than treating all oil related applications as equivalent. The intended mechanical compression and handling frequency also affect the selection.
Clean the receiving surface before insertion and check that the stopper reaches its designed position without a folded section. Do not drive a larger part farther into the opening to compensate for a profile mismatch. Inspect the contact region after removal and preserve the material identity during replacement. A new stopper should restore the original geometry and formulation for that exact location, even when several nearby closures share the same nominal size reference.
Photos illustrate structure or material appearance only. NBR rubber sealing stoppers in a 28 mm size configuration close a defined opening with a molded profile. 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.