Custom Silicone Sealing Sleeve for Electronic Product Assembly

A silicone sealing sleeve does not need complicated geometry to become an important part of an electronic assembly. When the material is soft and the component fits directly around another feature, small changes in the inner profile or flange position can affect how the part installs and seats.

For this project, we manufactured 50,000 black silicone sealing sleeves for an electronic product supplied to a customer in Italy.

Each part measures approximately 25 × 25 × 20 mm and uses silicone with a hardness of around 30 Shore A. The design combines an open cylindrical sleeve with a wide base flange, creating a soft interface between the silicone component and the surrounding product structure.

This was not a standard rubber sleeve selected from a catalog. The geometry was manufactured according to the customer's product design.

Project Details

The Inner Profile Is the Starting Point

The most important feature of this component is not its outside diameter. It is the open sleeve in the center.

This area interfaces directly with the mating component. The silicone needs to follow that geometry while the wider flange controls how far the sleeve seats into the assembly.

In practice, the part works as a combination of three related features:

inner opening → flexible sleeve → seating flange

Changing one can influence the others.

An incorrect inner profile may change the fit. Variation in the sleeve wall can affect how easily the part deforms during installation. The flange determines the final seating position and contact with the surrounding surface.

For this reason, a custom silicone sealing sleeve should be reviewed in relation to the component it fits around, not simply as an isolated rubber part.

30 Shore A Makes This a Soft Silicone Component

At approximately 30 Shore A, this part is noticeably soft and flexible.

That softness is useful for a sleeve-type component because the material can conform around the mating geometry during assembly. At the same time, the molded shape still needs to remain consistent enough for repeat installation across the production batch.

Hardness alone, however, does not define the behavior of the part.

A thin silicone wall bends more easily than a thick one even when both use the same 30 Shore A material. The inner diameter, wall section, transitions and flange geometry therefore need to be considered together.

For custom molded silicone parts, we follow the customer's specified material, Shore hardness and geometry rather than assuming one standard silicone formulation is suitable for every application.

A Sleeve Is Different from a Plug or Standard Grommet

Although small silicone parts can look similar, their functions and critical features may be quite different.

A solid plug normally fills or closes an opening. This component remains open through the center and instead forms a flexible interface around another feature.

That difference changes what needs attention during manufacturing.

For this sleeve, the inner opening, cylindrical wall and seating flange are more relevant than the external appearance alone.

It also explains why a standard rubber grommet may not always be suitable. If the electronic product requires a particular inner profile, flange position or overall height, using the closest available standard component can force unnecessary compromises into the surrounding design.

Custom silicone molding allows the rubber component to follow the product, rather than redesigning the product around a standard rubber part.

What Matters Before the Part Goes into Production?

Before molding a custom silicone sleeve, we first need to understand how the component is expected to fit.

The customer's 2D and 3D data provide the basic geometry, but assembly information can add useful context.

For a part like this, the manufacturing review may pay particular attention to:

• inner opening and mating dimensions;
• local wall thickness;
• sleeve height and profile;
• flange dimensions;
• transition between the sleeve and flange;
• functional molded edges;
• areas that may deform during handling or assembly.

Not every dimension needs the same level of control.

The objective is to identify the features that actually influence the customer's assembly and manufacture those areas according to the drawing requirements.

From a Soft Sample to 50,000 Production Parts

The first molded samples answer an important question: does the actual silicone component fit and behave as expected?

Once that is confirmed, a 50,000-piece order introduces a different requirement—keeping the approved condition consistent throughout production.

For this project, that means maintaining the inner profile, flange geometry, overall molded shape and specified material condition across the batch.

Soft silicone parts also need to be handled appropriately during inspection. Because the material can deform under force, measurement methods should take the flexibility of the component into account rather than treating it like a rigid machined part.

Molded edges around functional interfaces are another area worth checking. Minor molding evidence in a non-critical location is different from excess material that could affect how the sleeve fits onto the mating component.

These are small details, but at 50,000 pieces, small details become production issues if they are not controlled consistently.

Custom Silicone Sleeves for Electronic Products

Silicone sleeves are used in electronic products wherever a design requires a soft interface around another component.

Depending on the application, similar custom molded parts may serve as flexible sleeves, grommets, protective interfaces, cushions or sealing components. Their final geometry and material hardness should follow the actual assembly requirements.

For this Italian project, the requirement was a small 30 Shore A silicone sealing sleeve manufactured in a 50,000-piece production batch.

Its geometry is not visually complicated. The manufacturing value lies elsewhere: producing a soft component that continues to fit the intended mating structure consistently from approved sample through volume production.

Custom Molded Silicone Parts from YS Precision

YS Precision manufactures custom silicone sealing sleeves and molded silicone rubber components based on customer drawings and product requirements.

We support different silicone hardness levels, colors and custom geometries for electronic and industrial applications, from initial sample verification through volume manufacturing.

If your product requires a non-standard silicone sleeve, grommet, flexible interface or molded sealing component, send us the 2D/3D data together with the material, Shore hardness, quantity and relevant mating-part information. We can review the component in the context of the assembly before tooling and production.