50 Durometer Natural Rubber Sheet
Short Description
50 Durometer Natural Rubber Sheet is a medium-soft polyisoprene elastomer sheeting compound offering a service temperature range of -70 to +180°F and elongation of 500% to 900%. Natural rubber delivers superior resilience, tensile strength, and excellent adhesion to fabrics and metals — performance characteristics that make it the material of choice for dynamic applications requiring energy absorption, abrasion resistance, and flex-crack resistance. At 50 Shore A, this grade balances conformability with moderate compression resistance for a broad range of gasket, cushioning, and vibration isolation applications.
Key Properties
- Hardness, Shore A: 50 ± 5 (ASTM D2240)
- Elongation: 500–900%
- Service Temperature Range: -70 to +180°F
- ASTM D2000 / SAE J200 Classification: AA
- ASTM D-1418 Designation: NR
- Recommended Shelf Life: 3 years
We want to help!
Enter your information and we'll get you in touch with our knowledgable staff. We know how important to the right product for your project.
Request a Consultation
- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Hardness, Shore A | 50 ± 5 | ASTM D2240 |
| Elongation, % | 500–900 | — |
| Temperature Range | -70 to +180°F | — |
| ASTM D2000 / SAE J200 Classification | AA | — |
| ASTM D-1418 Designation | NR | — |
| MIL-R-3065 / SAE J-14 / MIL-STD-417 Classification | RN | — |
| Recommended Shelf Life | 3 years | — |
Mechanical Properties
| Property | Rating |
| Compression Set | Excellent |
| Abrasion Resistance | Excellent |
| Impact Resistance | Excellent |
| Resilience (Cold) | Excellent |
| Resilience (Hot) | Excellent |
| Flex Cracking Resistance | Excellent |
| Tear Resistance | Very Good |
| Flame Resistance | Poor |
Environmental Properties
| Property | Rating |
| Ozone Resistance | Poor |
| Weather Resistance | Poor to Fair |
| Sunlight Resistance | Poor |
| Steam Resistance | Fair to Good |
| Water Resistance | Very Good |
| Oxidation Resistance | Good |
| Gas Permeability | Fair to Good |
| Radiation Resistance | Fair to Good |
Compliance
- ASTM D2000 / SAE J200 Classification AA — Compliant
- MIL-R-3065 / SAE J-14 / MIL-STD-417 Classification RN — Compliant
- Automotive gaskets and seals
- Industrial belts and vibration dampers
- Construction components and expansion joints
- Conveyor systems and machine mounts
- Abrasion-resistant liners and wear pads
Common industries: Automotive, General Industrial, Construction, Material Handling, OEM Equipment.
50 Durometer Natural Rubber Sheet is the medium-soft grade in the Natural Rubber Sheet line, offering 50 Shore A hardness that provides a balance between the maximum conformability of the 40 Durometer grade and the compression resistance of firmer grades. The high elongation range of 500% to 900% supports energy absorption and dynamic deflection across a wide range of loading conditions, and the polyisoprene polymer delivers outstanding resilience, abrasion resistance, and flex-crack resistance that are characteristic of the natural rubber family.
The -70 to +180°F service temperature range supports both extreme cold-environment performance and moderate elevated-temperature service. Natural rubber’s outstanding adhesion to fabrics and metals makes this grade well suited to bonded and laminated constructions used in belts, mounts, and vibration isolation assemblies. Compression set, abrasion resistance, impact resistance, and resilience are all rated Excellent; tear resistance is rated Very Good.
Note that natural rubber has poor resistance to ozone, UV, sunlight, petroleum-based oils, and flame — application environments should be evaluated accordingly.
What differentiates 50 Durometer Natural Rubber Sheet from the 40 Durometer, 60 Durometer, and 70 Durometer grades?
50 Durometer Natural Rubber Sheet is the medium-soft grade in the line, providing a balance between the maximum conformability of 40 Durometer Natural Rubber Sheet and the higher compression resistance of the 60 and 70 Durometer grades. It is well suited for applications requiring moderate sealing load with high elongation and resilience. 60 Durometer Natural Rubber Sheet is the mid-range grade, and 70 Durometer Natural Rubber Sheet is the firmest grade for high-load sealing and vibration isolation applications.
What makes natural rubber superior to synthetic elastomers for dynamic applications?
Natural rubber (polyisoprene) provides a combination of resilience, tensile strength, and elongation that synthetic elastomers typically cannot match at equivalent hardness. Its cold and hot resilience are both rated Excellent, meaning it recovers rapidly from dynamic deflection without significant heat buildup — a critical property for belts, mounts, and vibration isolators subjected to repeated loading cycles.
What is the service temperature range for 50 Durometer Natural Rubber Sheet?
The service temperature range is -70 to +180°F, as listed on the Technical Datasheet.
What are the limitations of natural rubber in outdoor or chemical environments?
Natural rubber has poor resistance to ozone, sunlight, UV exposure, and weathering, and is not recommended for contact with petroleum-based oils, fuels, gasoline, mineral oil, or most hydrocarbon solvents. Applications involving these exposures should consider a synthetic elastomer such as EPDM or nitrile. Salt water and sodium hydroxide are rated as having little or minor effect and are acceptable.
How should 50 Durometer Natural Rubber Sheet be specified?
Specify grade (50 Durometer Natural Rubber Sheet), thickness, applicable classification (ASTM D2000 AA or MIL-R-3065 RN as required), dimensional tolerances, and finished format.
