Custom molded rubber
Custom Molded Rubber Grommets and Plugs
Grommets and plugs are small molded parts that line or close a hole. A grommet lines a panel hole so a cable, wire or tube passes through without chafing, and a plug closes an opening. Conquest Seal supplies them made to your drawing, from the domestic molders it distributes for or through our overseas manufacturing program, with Conquest Seal as the manufacturer of record on that route.
Quotes answered within one business day. A person answers (714) 632-9830, Pacific business hours.
- Part types
- grommets and plugs, to your drawing
- Sourcing
- domestic molders Conquest Seal distributes for, or made to your print through our overseas manufacturing program and imported
- Manufacturer of record
- the molder (domestic route); Conquest Seal (import route)
- Processes
- compression, transfer and injection molding
- Material
- ASTM D2000 or SAE J200 callout, AMS or MIL document, or a named compound
- Tolerances
- the ARPM class on your drawing, A1 high precision to A4 basic
- Tooling
- built to your drawing, held for your part
- Documentation
- certificate of conformance with every order; material certification and batch test report on request
Grommets
A grommet is specified by the panel it fits and what passes through it: the panel thickness its groove must grip, the hole it fills, and the diameter or range of the cable, wire or tube. Say whether it has to seal the hole against water or dust, whether it is molded closed and pierced at assembly, and whether it is split to fit over a cable already in place. Connector makers use molded grommets at the back of an insert to seal around each wire, as the connectors page describes.
Plugs
A molded plug is specified by the hole it fits, how it is held in place, by a lip, a barb or a flange, and whether it has to come out again. A pull tab or a grip ring on the drawing makes a plug easy to remove by hand. If the plug has to let air through while it keeps water or dust out, say so on the drawing.
What to specify
The RFQ checklist for custom molded parts explains each item. For a grommet or plug, the ones that matter most are these.
- The drawing, and the 3D model as a STEP file if you have one.
- The mating dimensions: panel thickness and hole, and the cable, wire or tube diameter.
- Whether the part must seal, and against what.
- The material by callout, document or compound, with the hardness and the color.
- The ARPM tolerance class for the dimensions that locate the part.
- Your annual usage and how it is released.
- Whether a mold already exists, what type it is and who holds it.
- The documents your quality system needs with the parts.
Two routes, one set of paperwork
Conquest Seal supplies custom molded parts two ways, set out on the custom molded rubber page. On the domestic route the part is molded by one of the domestic molders Conquest Seal distributes for, and that molder is the manufacturer of record. On the import route the part is made to your print through our overseas manufacturing program and imported, and Conquest Seal is the manufacturer of record and issues the certificate. The quote names the route.
A certificate of conformance ships with every order. Material certification and a batch test report are available on request, and so is AS9102 first-article documentation when your purchase order calls for it.
Tooling
Tooling is built to your drawing and held for your part. Who owns the tool is set by the agreement for the part: it can be yours or Conquest Seal's. The tool can be held stateside when production is domestic; otherwise it is held at the overseas molder in the program. If a mold already exists, say what type it is and who holds it, because whether it can be brought into the program depends on the type of mold.
Materials
Molded parts are quoted in the same compound families as the O-rings, among them nitrile, FKM, EPDM, silicone, fluorosilicone, HNBR, FFKM and polyurethane. The callout on the drawing governs: an ASTM D2000 or SAE J200 line callout, an AMS or MIL document, or a named compound with its data sheet. Each family has its own page with what it suits and its published service range.
Frequently asked
What do I need to specify for a custom rubber grommet?
The panel thickness the groove must grip, the panel hole, and the diameter or range of what passes through it, plus the material, the hardness and whether it must seal. A drawing with those dimensions is what the quote is written against.
Can a grommet be molded closed and pierced at assembly?
Yes. A grommet molded with a thin closed membrane is pierced when the cable or wire goes through, so the unused ones stay sealed. Show the membrane and its thickness on the drawing.
How is a molded plug held in place?
By a lip, a barb or a flange molded into it, sized to the hole it fits. Show the hole and the wall or panel thickness on the drawing, and say whether the plug has to come out again.
Who is the manufacturer of record on an imported molded grommet or plug?
Conquest Seal. On parts made through the overseas manufacturing program, Conquest Seal is the manufacturer of record and issues the certificate of conformance.
Related pages
Sources
- The ARPM Rubber Handbook, Association for Rubber Products Manufacturers, ARPM MO-1, Eighth Edition, 2020, chapter 1, Molded Rubber Products (tolerance designations only), read 2026-10-10.
- ASTM D2000: Standard Classification System for Rubber Products in Automotive Applications, public scope, read 2026-09-25.
Related guides
Setting Conquest Seal up as a supplier?
Orders are handled under Conquest Seal's AS9100D quality management system, whose certificate scope includes distribution.
Send the grommet or plug drawing
The drawing, the mating dimensions, the material callout or compound and your annual usage. A Conquest representative replies with the quote and names the route. Quotes answered within one business day. A person answers (714) 632-9830, Pacific business hours.
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