Hongjie manufactures closed-center rubber grommets for blanking unused panel holes, service openings and assembly ports. Unlike wire or cable grommets, these parts have no pass-through opening. Send the hole diameter, panel thickness, groove dimensions and required cap profile for fit review and sampling.
Blind rubber grommets close holes and service openings that do not carry wires or cables. These closed-center parts are also used as closed-hole grommets or rubber panel-hole plugs. The retaining groove is matched to the hole diameter and panel thickness for a secure fit.
The center is fully molded with no pass-through hole, making the part suitable for blanking unused openings.
A molded groove grips the panel edge and helps keep the grommet seated after installation.
Groove width and groove diameter are matched to the panel thickness and hole size rather than selected by outside diameter alone.
The exposed cap can be flat, domed or raised to suit clearance, appearance and access requirements.
Flexible rubber allows the opening to stay closed in normal use while remaining removable when later service access is needed.
Tell us whether the part only needs to block dust and debris or must meet a defined water-resistance requirement.
For a blind grommet, fit depends on the panel opening, panel thickness and retaining groove. Send these dimensions with the required cap profile so the part can be checked before sampling.
| Product Specifications | |
|---|---|
| Product Type | Blind Rubber Grommets |
| Parent Category | Grommets |
| Primary Function | Blanking unused panel holes and service openings |
| Center Design | Closed / No cable pass-through |
| Hole Diameter | According to drawing, sample, or measured panel opening |
| Panel Thickness | Matched to retaining-groove width |
| Groove Dimensions | Groove diameter and width according to panel fit |
| Cap Profile | Flat, domed, raised, or drawing-specific |
| Rubber Material | EPDM, NBR, Silicone, HNBR, Neoprene, FKM |
| Hardness | 10–90 Shore A |
| Compliance Options | FDA, NSF, RoHS, REACH where required |
| Insertion Requirement | Specify maximum or target insertion force if controlled |
| Retention Requirement | Specify pull-out or retention force if controlled |
| Environmental Requirement | Dust, water, oil, chemical, outdoor, or temperature exposure |
| Inspection | Dimensions, appearance, fit, and project-specific checks |
| Quality System | IATF 16949 certified production support |
A blind grommet should be sized from the actual hole and panel, not from cap diameter alone. Hole diameter, panel thickness, groove fit and cap clearance are reviewed together before sampling.
Center Design
Groove & Cap Profile
These parts are for openings that stay closed. If a conductor must pass through the panel, use rubber wire grommets for small wires or rubber cable grommets for cable entries instead.
Closes punched or drilled holes that are not used in the current panel or equipment configuration.
Blanks unused knockouts and access holes in control cabinets and electrical enclosures.
Covers holes used only on certain product variants so one panel design can support more than one assembly.
Keeps a service or inspection opening closed during normal operation while allowing later removal for access.
Keeps dust and debris out of an opening during handling, storage or assembly before the final configuration is completed.
Closes unused ports on outdoor housings where the material may need resistance to weather, ozone and moisture.
Send the panel hole size, panel thickness, groove dimensions and required cap profile. We can review the fit from a drawing or sample and confirm the checks needed before batch production.
We start with the actual hole diameter and panel thickness, then check the space available for the flange and exposed cap.
Groove diameter, groove width, overall diameter and cap height are defined around the panel fit and required clearance.
Samples can be installed in the actual panel or a representative test plate to confirm seating and installation feel.
Where required, pull-out retention can be checked together with dimensions, appearance and other project-specific inspection points.
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