Waterproof Rubber Seals

Category: Custom O-Rings & Rubber Seals

Custom bulb seals, hatch gaskets and extruded profiles are engineered to keep moisture, dust and air out of marine, industrial and outdoor equipment enclosures.

Parts are molded, extruded or die-cut at Hongjie’s 11,000 m² Shenzhen facility, backed by more than 25 years of sealing manufacturing experience and IATF 16949:2016 / ISO 13485:2016 certified systems. Waterproof profiles are available in EPDM, silicone and neoprene, with flange and housing gaskets produced to the same tolerance standards.

Applications

Marine
Hatch covers, deck access panels, and cargo hold covers sealed against spray and standing water.
Electrical & Industrial Enclosures
Rubber parts for electrical equipment that exclude moisture and dust from control cabinets.
RV, Trailers & Storage Containers
Compartment doors, ramp seals, and vent gaskets that stop water and drafts.
Outdoor & Heavy Equipment
Housings and access panels exposed to rain, wash-down, and dust.

Automotive door and window sealing runs on a different profile family, covered under Automotive Rubber Seals.

Seal Types & Formats

Bulb/Trim Seals
Extruded profiles that push onto a flange edge, combining a rigid trim with a flexible sealing bulb.
Hatch & Access Panel Gaskets
Molded or die-cut profiles compressed between a lid and frame.
Molded Enclosure Seals
Custom-profile gaskets fitted into cabinet and housing openings.

Most trim, bulb, and gasket cross-sections submitted for quoting match one of our 3,500+ existing extrusion and mold tools, so production can start from a proven die instead of a new one — cutting tooling cost and lead time. Our engineers compare your drawing against the existing library first and only quote new tooling when no match exists.

Cable and wire entry points are sealed differently — with automotive waterproof rubber grommets or custom waterproof rubber grommets built around a single conductor, not a panel edge.

Spec Reference

Profile Type	Material Options	Durometer	Temperature Range	Sealing Rating	Compression Range
Bulb/Trim Seal	EPDM, Neoprene	Application-specific	−60°C to +325°C*	Splash / wash-down (not independently IP-certified)	Confirmed at drawing review
Hatch/Access Gasket	EPDM, Silicone, Neoprene	Application-specific	−60°C to +325°C*	Static immersion (not independently IP-certified)	Confirmed at drawing review
Molded Enclosure Seal	EPDM, Silicone, NBR	Application-specific	−60°C to +325°C*	Splash / dust exclusion (not independently IP-certified)	Confirmed at drawing review

*Range spans our full compound portfolio, not any single material — confirmed per compound at quote stage.

Extrusion Tolerances & Processing

Extruded and molded seal cross-sections hold to the following dimensional control:

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

colorful rubber seals lined up on a metal table in a lab

Bulb and trim profiles run through beading for the edge-grip section, adhesive-backed strips are finished with PSA lamination, and large-format panel gaskets are cut by water-jet or kiss-cut from sheet stock for thinner sections.

Materials & Performance

Every compound is tested against 500+ fluids and chemicals for compatibility before it goes into production tooling.

EPDM
UV, ozone, and weather resistance; the standard choice for outdoor trim and hatch seals.
Silicone
Holds flexibility across temperature extremes.
Neoprene (CR)
General-purpose waterproofing for storage and marine use.
NBR
For enclosures also exposed to oils or fuels.

technician measuring rubber seal with caliper over technical drawing

Why Source From Hongjie

Hongjie holds IATF 16949:2016, ISO13485:2016, and UL certification, with FDA and NSF compliant material options for enclosures that need documentation. A 25+ engineer team, a library of 3,500+ existing profiles and tools, and export to 45+ countries support both prototype runs and ongoing OEM supply.

Request a Quote

Send your drawing, target profile, and operating environment for a waterproof rubber seal quote. Our engineers check it against the existing tool library, confirm material and tolerance, and quote tooling only when a new die is required.

FAQ

Frequently Asked Questions

What's the minimum order quantity for a waterproof seal profile?

MOQ depends on whether your profile matches one of our 3,500+ existing extrusion or mold tools — matched profiles generally support lower minimums than a new custom die. Submit your drawing for the exact quantity.

How long does new tooling take, and what does it cost?

Tooling lead time and cost depend on profile complexity and whether an existing tool is a match. If no match exists, our engineers quote both the new die and schedule after reviewing your drawing.

How fast can I get a sample?

Functional prototypes ship in as little as 3–5 business days once material, profile, and dimensions are confirmed.

What drawing formats do you accept?

We accept STEP, IGES, and other major CAD formats for engineering review and quoting, along with AS568A and metric dimensional data.