Natural Cork Composition Sheets
Product Description
Product Detail
Natural Cork Composition Sheets for Flange Gaskets, Compressor Seals and General Industrial Gasketing
Natural cork composition sheet is an economical all-purpose gasket material made from 10/20 grind composition cork. It is supplied in rolls and sheets, and is chosen because it does the two things a gasket has to do — it compresses into a surface and it recovers as bolt load relaxes — at a lower cost per part than most rubber-binder sheet materials.
This is the general-purpose grade in the Kaxite cork sheet range. When the working environment involves oil, fuel, weather or chemical exposure, the nitrile or neoprene-binder cork rubber sheet is the better fit. For dry, light to medium duty sealing, natural cork composition sheet remains the most cost-efficient choice.
Standard Sheet Sizes and Thicknesses
Natural cork composition sheet is produced in five standard thicknesses and five standard sheet sizes. All thicknesses below are available in every listed sheet size, so specification comes down to the flange or joint dimensions and the bolt load the gasket needs to carry.
| Thickness | 12" × 12" | 12" × 24" | 12" × 36" | 24" × 24" | 36" × 36" |
|---|---|---|---|---|---|
| 1/16" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 3/32" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/8" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/4" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 3/8" | ✓ | ✓ | ✓ | ✓ | ✓ |
| 1/2" | ✓ | ✓ | ✓ | ✓ | ✓ |
Custom thicknesses and sheet sizes can be produced on request. Send your flange drawing or required dimension and we will confirm availability.
Material Specifications
The figures below reflect typical values for 10/20 grind natural cork composition sheet. Actual values vary slightly by thickness and by production batch — please request a batch certificate if your application has a hard specification limit.
| Property | Typical Value | Notes |
|---|---|---|
| Composition | 10/20 grind composition cork | Cork granules bound without a rubber binder |
| Thickness Range | 1/16" to 1/2" | Custom thicknesses on request |
| Sheet Sizes | 12" × 12" to 36" × 36" | Five standard sizes |
| Supply Format | Sheets and rolls | Roll format depends on thickness |
| Compressibility | Good | Compresses into surface irregularities under bolt load |
| Recovery | Good | Recovers as bolt load relaxes, maintaining seal |
| Binder | None (composition cork) | Not oil, fuel or solvent resistant |
| Primary Service | Dry, light to medium duty sealing | General industrial gasketing |
| Density | Standard composition cork density | Batch-specific; certificate available |
| Surface | Smooth, void-free | No through holes or voids in the sheet matrix |
What Natural Cork Composition Sheet Does Well
- Compresses and recovers. Cork granules deform under bolt load and spring back when load relaxes. That two-way behaviour is what keeps a gasket sealed over thermal cycling, and it is why cork sheet has been used in flange gasketing for decades.
- Cost-efficient. No rubber binder means a lower raw-material cost per sheet than cork rubber grades. For dry, light to medium duty joints, it is usually the most economical option that still works.
- Cut-to-size simplicity. Sheets and rolls can be cut with standard gasket tooling — hollow punches, knives or die cutting. No special equipment is needed to turn a sheet into finished gaskets.
- Void-free surface. The sheet has no through holes or voids, which matters at thin gauges where a single void would become a leak path under pressure.
- Wide thickness range. From 1/16" up to 1/2", one material covers everything from thin flange gaskets to thicker cushioning and compressor sealing applications.
When to choose a different grade
Natural cork composition sheet has no rubber binder, so it is not the right choice for oil, fuel, solvent or chemical contact. If the seal will see petroleum-based media, specify cork and nitrile rubber sheet. If the joint is outdoors or exposed to weather and chemicals, specify cork and neoprene rubber sheet.
Storage and shelf life
Composition cork sheet should be stored flat, dry and away from direct sunlight. Under those conditions it holds its dimensions and mechanical properties for extended periods, so stock can be cut to order rather than held as finished gaskets.
Typical Applications for Natural Cork Composition Sheet
Cut gaskets for low-pressure water, air and dry service flanges where the joint does not see oil or chemical contact.
Gaskets and pads in compressor assemblies where moderate compressibility and good recovery are needed.
Equipment covers, inspection plates and general purpose sealing where a low-cost compressible sheet works.
Cushioning and mounting pads where the cork structure absorbs vibration and impact.
Sealing and gasket applications in air handling systems that stay dry and do not see chemical exposure.
Sheet can be die cut, punched or knife cut into customer-specific gasket shapes and pads.
Non-conductive cushioning and gasket parts in panel and enclosure assemblies.
Underlay and cushioning layers where impact absorption and long service life are required.
On-site gasket cutting from stock sheet, eliminating the wait for a custom gasket to be produced.
How to Specify Natural Cork Composition Sheet
- Confirm the working media. If the joint is dry air, water or general environmental exposure without oils or solvents, natural cork composition sheet is suitable. If oil or fuel contact is expected, choose the nitrile grade instead.
- Choose the thickness. Thinner sheets (1/16"–1/8") suit machined flanges with good surface finish. Thicker sheets (1/4"–1/2") suit rougher surfaces or joints that need greater compressibility.
- Select the sheet size. Match sheet size to the gasket dimensions. 12" × 12" covers most small gaskets; larger sheet sizes reduce offcut waste for bigger parts.
- Confirm supply format. Sheets for cut-to-size gasket production; rolls for continuous or high-volume cutting operations.
- State any certification requirement. If your specification calls for a specific standard or a batch certificate, confirm this at the quotation stage.
Natural Cork Composition Sheet FAQs
What is natural cork composition sheet made from?
It is made from 10/20 grind composition cork — natural cork granules that are bonded into a sheet form without adding a rubber binder. That distinguishes it from cork rubber sheet, which adds a nitrile, neoprene or general-purpose rubber binder.
What is the difference between natural cork composition sheet and cork rubber sheet?
Natural cork composition sheet has no rubber binder, so it is limited to dry, light to medium duty sealing. Cork rubber sheet adds a rubber binder which improves flexibility, shelf life and resistance to oils, fuels, weather or chemicals, depending on which binder is used.
Can natural cork composition sheet be used with oil or fuel?
No. Without a rubber binder, natural cork composition sheet is not oil, fuel or solvent resistant. For those media, specify the cork and nitrile rubber sheet grade instead.
What thicknesses and sheet sizes are available?
Five standard thicknesses: 1/16", 3/32", 1/8", 1/4", 3/8" and 1/2" — and five standard sheet sizes: 12" × 12", 12" × 24", 12" × 36", 24" × 24" and 36" × 36". Custom thicknesses and sizes can be produced on request.
Is the material supplied in sheets or rolls?
Both. Natural cork composition sheet is supplied in sheet form and roll form. The availability of roll format depends on the thickness required.
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 matrix, which is important for thin gaskets where a void would become a leak path.
How should natural cork composition sheet be stored?
Store flat, dry and out of direct sunlight. Under those conditions the material holds its dimensions and mechanical properties for extended periods and can be cut to size on demand.
Can you supply other cork-based grades?
Yes. Kaxite also supplies cork and nitrile rubber sheet (H-series, MIL C 6183 B Class 1) and cork and neoprene rubber sheet (E-series, MIL C 6183 B Class 2, soft / medium / firm density), plus general cork rubber sheet for indoor light to medium duty applications.
Request a Natural Cork Composition Sheet Quotation
Send us the working media, required thickness and sheet size. Kaxite will confirm availability and lead time. If your application involves oil, fuel or chemical contact, tell us and we will recommend the appropriate cork rubber grade instead.