CUSTOM RUBBER & SILICONE MANUFACTURING

Test tube plug/solid silicone plug/rubber cone plug

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 test tube plug closes the open end of a tube with a removable solid rubber body. This custom design can be produced in silicone, with dimensions, hardness and color chosen for the intended tube and handling routine. The cone profile allows the contact position to change along its length, so both end diameters matter when establishing the fit.

Consider the mouth shape as well as its opening diameter. A rolled rim, straight neck or short opening can place the contact band at a different depth. The plug should seat with enough exposed material for controlled removal; forcing most of the body inside the tube makes handling difficult and may stress a fragile mouth. Support the tube close to the opening when inserting or withdrawing the closure.

Select the silicone formulation around the contents and cleaning process. Keep the contacting surfaces free of deposits, and inspect the tube rim for damage before reuse. A chipped rim or distorted plug changes the fit even when the original sizes were appropriate. Choose a dedicated vented arrangement if the process needs a passage through the closure.

Material options
Custom silicone compound; formulation and geometry developed together.
Hardness selection
Silicone options: 20–80 Shore A. Support the tube close to the opening when inserting or withdrawing the closure.
Custom geometry
Consider the mouth shape as well as its opening diameter.
Fit evaluation
A Test tube plug closes the open end of a tube with a removable solid rubber body.
Color & OEM
Custom colors; OEM identification positioned outside closure contact surfaces.

Photos illustrate structure or material appearance only. A rolled rim, straight neck or short opening can place the contact band at a different depth. 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].