Custom manufacturing example · Silicone caps and plugs/ Rubber round dust cap

CUSTOM RUBBER & SILICONE MANUFACTURING

Silicone caps and plugs/ Rubber round dust cap

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

Silicone caps and plugs offer two approaches to closing a round feature. A cap covers the exterior of an end, whereas a plug occupies an opening. Choosing between them begins with the surfaces available for engagement and whether the inside or outside must remain clear. The product range allows changes to dimensions, compound, color and logo.

A cap may need clearance around the outside of the component, including space for fingers during removal. A plug needs sufficient internal depth and a shape that does not interfere with features farther inside. Neither should be forced past an unexpected shoulder simply because its diameter appears close to the opening.

For a dust-cover application, compare retention during ordinary handling with the effort needed for access. Repeated removal can reveal a fit that is awkward despite appearing satisfactory when first assembled. Keep the mating surfaces clean and inspect them when reopening the closure. The round form does not itself establish a pressure seal or a universal water rating; those functions depend on the specified part and its completed fit.

Material options: Custom silicone compound; formulation and geometry developed together.
Hardness selection: Silicone options: 20–80 Shore A. Repeated removal can reveal a fit that is awkward despite appearing satisfactory when first assembled.
Custom geometry: Neither should be forced past an unexpected shoulder simply because its diameter appears close to the opening.
Fit evaluation: For a dust-cover application, compare retention during ordinary handling with the effort needed for access.
Color & OEM: Custom colors; OEM identification positioned outside closure contact surfaces.

Photos illustrate structure or material appearance only. A plug needs sufficient internal depth and a shape that does not interfere with features farther inside. 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

End Cap Size Catalog

Compare inside diameter A with the outside of the part being covered. Check inside depth C and overall dimensions B and D for available clearance. These RSE references show a round cap with one closed end.

RSE End Caps

43 closed-end cap sizes. A is the inside diameter and C is the usable internal depth; B and D describe the outside envelope.

Generated product visualization of RSE End Caps. — Illustrative product rendering. Refer to the table for dimensions.

P/N	A	B	C	D	Color	Unit
RSE3.7-7-9	3.7	7	9	11	black,white	mm
RSE4.7-8-9	4.7	8	9	11	black,white	mm
RSE5.7-9-10	5.7	9	10	12	black,white	mm
RSE6.7-10-10	6.7	10	10	12	black,white	mm
RSE7.7-11-11	7.7	11	11	13	black,white	mm
RSE8.7-12-12	8.7	12	12	14	black,white	mm
RSE9.7-14-13	9.7	14	13	15	black,white	mm
RSE10.7-15-14	10.7	15	14	16	black,white	mm
RSE11.7-16-15	11.7	16	15	17	black,white	mm
RSE12.7-17-15	12.7	17	15	18	black,white	mm
RSE13.7-18-15	13.7	18	15	18	black,white	mm
RSE14.7-19-15	14.7	19	15	18	black,white	mm
RSE15.7-20-16	15.7	20	16	19	black,white	mm
RSE16.7-21-16	16.7	21	16	19	black,white	mm
RSE17.7-22-16	17.7	22	16	19	black,white	mm

Need a different fit? Share the opening dimensions, mating profile and intended use for a custom size.

From part requirements to production

Define the part

Identify key dimensions, mating surfaces and quantity

Review material & tooling

Agree the compound and manufacturing approach

Evaluate the sample

Review the fit and agreed requirements in the assembly

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.