Custom molded rubber
Custom Molded Rubber Gaskets and Seals
A gasket or seal is molded when its shape cannot be cut from sheet: a bead or lip on the sealing face, a round or profiled section, a closed shape that must have no joint, or a compound that is not made as sheet. Conquest Seal supplies custom molded gaskets and seals 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. Flat parts in a sheet material are cut instead, on the waterjet in Orange, California.
Quotes answered within one business day. A person answers (714) 632-9830, Pacific business hours.
- Part types
- molded gaskets, molded seals and molded diaphragms, 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
Molded or cut from sheet?
A flat gasket of even thickness is cut, not molded. It goes straight from the drawing to the waterjet in our own shop, with no mold to build, and the custom gaskets page covers that route. Molding is the route when the section carries a bead, a lip or a groove, when the gasket is a closed shape that must have no joint, such as a door or cover gasket on an enclosure, when a metal insert is bonded in, or when the compound is not sold as sheet. If a part could go either way, send the drawing and both are quoted.
Seals with a molded profile
Lip seals, cup seals and other profiled sections are molded to the cross section on your drawing, in the compound the callout names, such as FKM, nitrile or silicone. Where a standard ring fits the groove, AS568 O-rings and X-rings are quoted from the size standard with no mold to build. A molded custom section is for a groove, a load or a shape that a standard ring does not fit.
Molded diaphragms are quoted the same way, to your drawing. Give the pressure, the stroke and the media the diaphragm works against, and mark any area that must stay free of flash.
What to specify
The RFQ checklist for custom molded parts explains each item. For a gasket or seal, the ones that matter most are these.
- The drawing with the sealing faces marked, and the 3D model as a STEP file if you have one.
- Where the parting line may fall, and where flash is not allowed.
- The material by callout, document or compound, with the hardness and the color.
- The ARPM tolerance class, and any dimension that needs a closer one called out on its own.
- The mating hardware: the groove or flange it seals, and how far the part is compressed there.
- 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
Should a flat rubber gasket be molded or cut from sheet?
Cut it if it is flat and of even thickness, because a cut gasket needs no mold. Mold it when the section carries a bead, lip or groove, when it is a closed shape that must have no joint, when a metal insert is bonded in, or when the compound is not made as sheet. Where it could go either way, send the drawing and both are quoted.
Can a seal be molded to a non-standard cross section?
Yes. A lip, cup or other custom section is molded to the cross section on your drawing, in the compound the callout names. Where a standard O-ring or X-ring fits the groove, it is quoted from the size standard instead, with no mold to build.
Which rubber can a molded gasket be made in?
The compound families quoted for molded parts include nitrile, FKM, EPDM, silicone, fluorosilicone, HNBR, FFKM and polyurethane. Name it on the drawing by an ASTM D2000 or SAE J200 callout, an AMS or MIL document, or a named compound with its data sheet.
Who is the manufacturer of record on an imported molded gasket?
Conquest Seal. On parts made through the overseas manufacturing program, Conquest Seal is the manufacturer of record and issues the certificate of conformance; material certification and a batch test report are available on request.
Are molded diaphragms quoted too?
Yes, to your drawing. Give the pressure, the stroke and the media the diaphragm works against.
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 gasket or seal drawing
The drawing, the material callout or compound, the tolerance class 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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