Cork and Neoprene Rubber Sheets
Kaxite cork and neoprene rubber sheet is a blend of high-quality cork granules and neoprene (CR) rubber binder, engineered for high resistance to weather, ozone, salt air, water and general chemical exposure. It is the grade specified when a gasket joint sits outdoors, sees moisture, or operates in a chemically exposed environment. The E-series is supplied in soft, medium and firm densities across eight standard thicknesses from 1/32" to 1/2" and five sheet sizes up to 36"×36". Each grade can be certified to meet Grades A, B or C of MIL C 6183 B Class 2. The cork component preserves compressibility and recovery, giving reliable sealing under thermal cycling and long-term outdoor exposure. Custom thicknesses and sheet sizes are available on request.Send Inquiry
Product Description
Cork and Neoprene Rubber Sheet — What It Is and When to Specify It
Neoprene (polychloroprene) rubber is the binder chosen when the joint will see weather, ozone, salt air, water immersion or general chemical exposure. It holds up better than natural rubber under UV and temperature cycling, and resists a broader set of chemicals than nitrile — but does not match nitrile's specific fuel and aromatic solvent resistance.
What the cork component adds
Rubber alone is flexible but lacks the structural compressibility that makes a gasket conform to a flange. Cork granules provide that: they deform into surface irregularities under bolt load and spring back as load relaxes, keeping the joint sealed through thermal cycling. Combined with a neoprene binder, the sheet gets both weather resistance and dimensional stability — an unusual combination that plain rubber or plain cork cannot deliver individually.
The result is a sheet that remains sealed for years in outdoor and moisture-exposed service, rather than hardening and losing its sealing force after a single season of temperature swings.
Where it fits in the Kaxite cork sheet range
The E-series is the weather and chemical grade. For oil, aromatic fuel and solvent contact use cork and nitrile rubber sheet (H-series, MIL C 6183 B Class 1). For dry, light to medium duty sealing use natural cork composition sheet.
Soft, Medium or Firm — Choosing the Right Density
The E-series is produced in three density grades. Density governs how much the sheet compresses under a given bolt load, which in turn determines how well it conforms to uneven surfaces and how much load it can carry without being extruded out of the joint.
How to choose
Match density to the flange stiffness and the surface finish. Soft grade for compliant surfaces and low-torque joints; medium as the default starting point for standard flanges; firm when the joint is steel-on-steel, torque is high, or extrusion is a risk. If you are unsure, send the flange drawing and bolt torque specification and we will recommend a density.
Standard Thicknesses and Sheet Sizes
The E-series cork and neoprene rubber sheet is produced in eight standard thicknesses and five standard sheet sizes. Every thickness below is available in every listed sheet size. All three density grades (soft, medium, firm) are available across the full range.
| Thickness | 12" × 12" | 12" × 24" | 12" × 36" | 24" × 24" | 36" × 36" |
|---|---|---|---|---|---|
| 1/32" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/16" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 3/32" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/8" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 3/16" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/4" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 3/8" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/2" | ✓ | ✓ | ✓ | ✓ | ✓ |
Thicknesses outside the eight listed above and sheet sizes larger than 36"×36" can be produced on request. Send the required specification and we will confirm availability and lead time.
Technical Specifications
Typical physical and performance values for the standard E-series cork and neoprene rubber sheet. Actual figures vary slightly with thickness, density grade and production batch — request a batch certificate where a hard specification limit applies.
| Property | Typical Value | Notes |
|---|---|---|
| Composition | Cork granules + neoprene (CR) rubber binder | High-quality grade cork and polychloroprene |
| Binder | Neoprene rubber (CR) | Weather, ozone and chemical resistance |
| Density Grades | Soft, medium, firm | All three available across full size range |
| Thickness Range | 1/32" to 1/2" | Eight standard gauges |
| Sheet Sizes | 12"×12" to 36"×36" | Five standard sizes |
| Supply Format | Sheets | Cut-to-size available |
| Weather Resistance | High | UV, ozone, temperature cycling |
| Water Resistance | High | Including salt water and moisture exposure |
| Chemical Resistance | Broad | General industrial chemicals, mild acids and alkalis |
| Compressibility | Good | Cork structure conforms to surface irregularities |
| Recovery | Good | Maintains sealing force as bolt load relaxes |
| Certification | MIL C 6183 B Class 2 | Grades A, B or C available |
| Surface | Smooth, void-free | No through holes in the sheet matrix |
MIL C 6183 B Class 2 Certification
The E-series can be certified to meet the three grades defined under MIL C 6183 B Class 2 — the neoprene-bound category. Grade selection depends on the mechanical and chemical requirement of the end application. Request certification at the quotation stage so the correct grade is produced and documented.
Highest grade within Class 2. Specified where maximum consistency under the standard is required for weather and chemically exposed joints.
Intermediate grade within Class 2. Covers general outdoor and industrial applications that meet Class 2 chemical requirements.
Class 1 vs Class 2 — which to specify
MIL C 6183 B Class 1 is the nitrile-bound category, giving the highest oil and aromatic fuel resistance. Class 2 is the neoprene-bound category, giving better weather, ozone and chemical resistance. This E-series is Class 2. If your application is primarily fuel or oil contact, specify the H-series nitrile grade instead.
Typical Applications
How to Specify Cork and Neoprene Rubber Sheet
- Confirm the working environment. This E-series is specified for weather, ozone, moisture, salt air and general chemical exposure. For oil or aromatic fuel contact, use the nitrile-bound H-series instead.
- Select the density grade. Soft for compliant surfaces and low-torque joints; medium as the general-purpose default; firm for rigid steel flanges and higher bolt loads.
- Choose the thickness. Thinner gauges (1/32"–1/8") suit machined flanges with good surface finish. Thicker gauges (3/16"–1/2") suit rougher surfaces or joints needing greater compressibility.
- Choose the sheet size. Match sheet size to the gasket dimensions — 12"×12" for small gaskets; larger sizes to reduce offcut waste on bigger parts.
- State the certification grade. If your specification calls for MIL C 6183 B Class 2, specify Grade A, B or C at the quotation stage.
Cork and Neoprene Rubber Sheet FAQs
What is cork and neoprene rubber sheet made from?
It is a blend of high-quality cork granules and neoprene (polychloroprene) rubber binder. The neoprene provides weather, ozone, water and chemical resistance, while the cork preserves compressibility and recovery for reliable sealing.
What is the difference between cork and neoprene rubber sheet and cork and nitrile rubber sheet?
Cork and neoprene rubber sheet (E-series) is bound with neoprene rubber, giving better weather, ozone, water and chemical resistance — MIL C 6183 B Class 2. Cork and nitrile rubber sheet (H-series) is bound with nitrile rubber, giving high resistance to oils, aromatic fuels and solvents — MIL C 6183 B Class 1. Choose based on the media and environment the joint will see.
Is this grade suitable for outdoor and marine use?
Yes. Neoprene is the standard binder for outdoor service because it resists UV degradation, ozone attack, salt air and water immersion better than natural rubber. It is commonly specified for marine deck fittings, outdoor equipment and infrastructure gaskets.
What densities are available and how do I choose?
Three density grades are available: soft, medium and firm. Soft compresses at the lowest bolt load and is best for delicate flanges and compliant surfaces. Medium is the general-purpose default for standard flanges. Firm carries the highest bolt load and is used on rigid steel flanges where extrusion is a concern. Send the flange drawing and torque specification and we will recommend a density.
What thicknesses and sheet sizes are available?
Eight standard thicknesses: 1/32", 1/16", 3/32", 1/8", 3/16", 1/4", 3/8" and 1/2". Five standard sheet sizes: 12"×12", 12"×24", 12"×36", 24"×24" and 36"×36". All three density grades are available across the full size range. Custom thicknesses and sizes can be produced on request.
Can the sheet be certified to MIL C 6183 B?
Yes. Each grade of the E-series can be certified to meet Grades A, B or C of MIL C 6183 B Class 2. Please state the required grade at the quotation stage so the correct grade is produced and documented.
Does the sheet contain through holes or voids?
No. The sheet has a smooth surface and does not contain through holes or voids within the cork-rubber matrix, which matters at thin gauges where a void would become a leak path under pressure.
What other cork-based grades does Kaxite supply?
Kaxite also supplies natural cork composition sheet (10/20 grind, general purpose, dry sealing) and cork and nitrile rubber sheet (H-series, MIL C 6183 B Class 1, oil and fuel resistant), plus a general cork rubber sheet for indoor light to medium duty applications.
Request a Cork and Neoprene Rubber Sheet Quotation
Send the working environment, required density grade, thickness, sheet size and — if applicable — the required MIL C 6183 B Class 2 grade. Kaxite will confirm availability, lead time and certification options. If your application involves oil or aromatic fuel contact, we will recommend the nitrile H-series instead.
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