CUSTOM RUBBER & SILICONE MANUFACTURING

28mm oil proof rubber plugs/(NBR) rubber sealing stoppers

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

Vulcanization workshop illustration with green molding presses and blue collection bins

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

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.

Material options
NBR compound options, customized alongside the profile and contact conditions.
Hardness selection
Solid rubber options: 30–90 Shore A. The intended mechanical compression and handling frequency also affect the selection.
Custom geometry
Do not drive a larger part farther into the opening to compensate for a profile mismatch.
Fit evaluation
The nominal reference should be coordinated with the body, head, and seating features required by the receiving part.
Color & OEM
Custom colors; OEM identification positioned outside closure contact surfaces.

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.

Choosing a material or hardness? Explore the selection guide →

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
RST Blind-Hole Plugs plan and section dimension guide.
Blind-hole variant shown. E = 0 indicates a solid shank. Use the dimensions listed for each part number.
PRODUCT APPEARANCE
Generated product visualization of RST Blind-Hole Plugs in matte black.
Illustrative product rendering. Refer to the table for dimensions.
P/NABCDEUnit
RST2.5-5.5-5.32.55.55.320mm
RST2.7-5.5-52.75.5520mm
RST3-4.3-4.534.34.50.80mm
RST3-7-73772.20mm
RST3.3-6.5-63.36.561.50mm
RST3.5-6.5-63.56.5620mm
RST3.8-7-10.53.8710.51.50mm
RST3.8-7-73.8771.50mm
RST3.8-7-63.8761.50mm
RST4-7.5-647.5620mm
RST4-9.5-749.572.50mm
RST4.3-8-64.3861.50mm
RST4.5-7.5-64.57.5620mm
RST4.8-6.8-3.64.86.83.60.90mm
RST4.8-9-74.8971.50mm

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

Working conditions

Identify temperature, contact fluids and repeated movement.

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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Send your requirements
and selected drawings

All files and photos you share with us are handled under strict confidentiality procedures and will not be disclosed to any third party.

DISCUSS THIS COMPONENT

Request a Custom Quote

You can also email us directly at [email protected].