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Custom O-Rings & Rubber Seals Banner Image

Custom Rubber Seals

Since 2001, Hongjie Sealing Technology has manufactured custom rubber seals at its 11,000 m² Shenzhen facility, handling tooling, molding, extrusion, and die-cutting in-house. Hongjie produces 50+ million precision-inspected seals annually for buyers in 45+ countries across automotive, medical, hydraulic, and industrial markets.

Products

Standard O-Ring & Seal Products

More than 3,500 standard profiles in AS568 and metric sizes are available alongside custom molding. Browse by size, material or temperature requirement:

Which Rubber Sealing Product Do You Need?

Match the part to its geometry before requesting a quote:

Product Typical geometry Common use
Seal (lip/oil/U-seal) Molded profile with a sealing lip or edge Rotating shafts, sliding rods, dynamic sealing
O-Ring Round cross-section ring Static or dynamic sealing in a machined groove
Gasket Flat or molded flange shape Static sealing between two mating surfaces
Washer Flat disc, often with a center hole Load spreading, vibration damping, light sealing
Grommet Ring with a channel or bore Cable/wire pass-through, panel edge protection

Choose an O-ring when the part seals through round cross-section squeeze in a machined groove. FKM/FFKM and silicone are available in AS568 and metric sizes.

For flat discs or spacers used across a bolted joint, see Custom Rubber Washers. For brackets, covers and other non-standard cross-sections, see Custom Molded Rubber Parts.

rubber O-ring compliance and certification support

Molded Rubber Seal Types We Manufacture

Production covers the shapes that fall specifically under "seal" rather than O-ring or gasket:

  • Lip seals and rotary shaft/oil seals
  • U-seals and V-seals for reciprocating rods
  • Custom profile and cross-section seals molded to a drawing
  • Diaphragm-style seals for pressure and media control
  • Rubber-to-metal bonded seals for structural or vibration-isolating joints
  • Sealing rings for valves and pumps, including high-pressure fluid system applications

ISO 13485:2016 certification and FDA/NSF-compliant compounds support medical device housings and fluid-contact seals, molded as Medical Silicone Molded Seals for OEM Assemblies.

Process

Manufacturing Processes

The production process is selected according to the seal geometry and performance requirements:

  • 1

    Injection and compression molding

    For closed geometries, grooves, logos and detailed molded features.

  • 2

    Extrusion

    For profiles with a constant cross-section, such as window, door and cabinet seals. Spliced joints should be considered during design.

  • 3

    Die-cutting and water-jet cutting

    For flat seals with uniform thickness cut from sheet stock.

  • 4

    Rubber-to-metal bonding

    For seals that require a rigid carrier or structural support.

  • Material Options for Custom Seals

Material Options for Custom Seals

OEM rubber seals need a compound matched to the fluid, temperature and regulatory environment before tooling starts, not after a failure in the field:

  • NBR (Nitrile)

    General oil and fuel resistance, cost-effective for industrial and automotive.

  • FKM (Viton®)

    High-temperature and aggressive-chemical service.

  • EPDM

    Weathering, ozone and water/steam resistance.

  • Silicone (VMQ)

    Wide temperature range, food and medical compliance.

  • HNBR

    Improved heat and abrasion resistance over standard NBR.

  • Neoprene (CR)

    Moderate oil resistance with good flame and weather resistance.

  • FFKM

    Extreme chemical inertness for aggressive process environments.

  • Polyurethane (AU/EU)

    Abrasion and load-bearing performance.

The NBR, FKM, and EPDM O-ring selection guide breaks down fluid compatibility and temperature limits for the three most-requested compounds.

Precision & Performance Specs

Two tolerance grades apply depending on how critical the dimension is — a standard tolerance grade for general fits, and a tighter precision tolerance grade for critical dimensions held with matched-metal tooling:

Dimension Range Standard Precision
0–10 mm ±0.10 mm ±0.02 mm
10–25 mm ±0.15 mm ±0.05 mm
25–50 mm ±0.20 mm ±0.08 mm
50–100 mm ±0.25 mm ±0.10 mm

Compound formulations extend service across roughly –60°C to +325°C.

Chemical compatibility is checked against a reference library of 500+ fluids, gases, and chemicals during material qualification. Compatibility with your specific media is confirmed at quoting rather than assumed from the general library.

Quality

Quality Certifications

  • IATF 16949:2016 certified

  • ISO 13485:2016 certified

  • UL certified for electrical applications

  • FDA and NSF compliant materials

  • SPC and Six Sigma methods targeting Cpk > 1.33 consistency

Industries

Industries We Serve

99.7%

ON-TIME DELIVERY

From Drawing to Delivery

Submit the part information

Send a drawing, sketch or failed sample. STEP, IGES and most major CAD formats are accepted. The engineering team can also support 3D CAD modeling and FEA simulation.


Confirm the material and design requirements

The quote is based on the actual part. Engineering reviews:

  • Seal geometry and critical dimensions

  • Compound, Shore A hardness and media compatibility

  • Precision tolerance and production method

  • Cavity count, tooling design and expected volume


Move from prototype to production

Functional prototypes can be available in as little as 3–5 business days. MOQ, tooling cost and production lead time are quoted per part because a single-cavity prototype tool and a multi-cavity production tool require different investment and volumes.

Rubber bushings, grommets, diaphragms and bonded metal parts can be quoted alongside a seal through custom rubber parts manufacturer capabilities.

Start Project Discussion with a drawing, sketch or failed sample.

O-RING & RUBBER SEAL FAQS

O-Ring & Rubber Seal FAQs

Answers to common questions about custom O-ring quotation, material selection, sealing conditions, compliance options and bulk order inspection.

What are rubber seals called?
Depending on geometry, a rubber seal may be called a lip seal, oil/shaft seal, U-seal, V-seal, or diaphragm seal. Round ring seals are O-rings, and flat static seals are usually called gaskets — match the term to the geometry before requesting a quote.
What do you need to quote a custom rubber seal?
A drawing or CAD file (STEP or IGES work directly), the target material or performance requirement, and any critical dimensions needing precision tolerance. That's enough for an engineer to review geometry and return a quote alongside a prototype timeline.
Is tooling required before you can get a price?
No — send a drawing first. Tooling design, cavity count and material all affect cost, so pricing, tooling investment, MOQ and lead time are calculated against the actual part rather than quoted as a flat rate up front.

    Submit Your Technical Inquiry

    Describe your application and our engineers will provide a tailored solution.

    Start Your Project

    Need Custom Rubber Components?

    Our engineering team reviews your specs and responds within 24 hours with material recommendations and competitive pricing.

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