CUSTOM RUBBER & SILICONE MANUFACTURING

Black Rubber Dust Cap Waterproof Silicone Plugs

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

A black rubber dust cap can be custom molded for an opening that remains closed between uses. The internal fit, cover depth, and exposed shape should suit the mating component. Black color defines the appearance, while the selected rubber or silicone formulation follows the temperature and substances at the installation.

Plan removal before surrounding parts restrict access. A cover needs enough reachable material to be handled without damaging its contact edge. The depth should allow it to seat fully rather than stop against an internal shoulder prematurely.

Clear loose dust from the surrounding area before opening the assembly. Keep the removed cap away from contaminated work surfaces and inspect its rim before refitting. Seat it evenly without rolling the mouth inward. Where water exposure is relevant, assess the complete fitted interface under its intended conditions rather than attributing protection to the cap alone. Replace a torn or permanently distorted cover with the matching profile so that its contact and handling regions return to their intended positions.

Material options
Custom silicone or rubber formulation; select the compound alongside the mating geometry.
Hardness selection
Silicone: 20–80 Shore A; solid rubber: 30–90 Shore A. The internal fit, cover depth, and exposed shape should suit the mating component.
Custom geometry
The depth should allow it to seat fully rather than stop against an internal shoulder prematurely.
Fit evaluation
Seat it evenly without rolling the mouth inward.
Color & OEM
Custom colors; OEM identification positioned outside closure contact surfaces.

Photos illustrate structure or material appearance only. The internal fit, cover depth, and exposed shape should suit the mating component. 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].