4120 Open Cell Natural Rubber
4120 is a medium firmness open cell natural rubber foam with an average density of 26 lb/ft³ and a compression deflection of 5–10 psi at 25%. It is rated for service from -20°F to 160°F and exhibits a compression set of 15% at 50% deflection at 158°F. The material is tan, available in thicknesses from 1/16″ to 1/4″, and features anti-slip, high-friction surface properties and exceptional abrasion resistance.
Key Properties
- Compression Deflection @ 25%: 5–10 psi (ASTM D1056)
- Compression Set @ 50% Deflection @ 158°F: 15% (ASTM D1056)
- Density (Average): 26 lb/ft³ (ASTM D1056)
- Compression Deflection Change After Oven Aging 168 Hours @ 158°F: ±20% (ASTM D1056)
- Temperature Range: -20°F to 160°F
- Abrasion Resistance: Yes
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Polymer | Natural Rubber | — |
| Cell Structure | Open Cell | — |
| Color | Tan | — |
| Density (Average) | 26 lb/ft³ | ASTM D1056 |
| Temperature Range | -20°F to 160°F | — |
| Abrasion Resistance | Yes | — |
Mechanical Properties
| Property | Value | Test Method |
| Compression Deflection @ 25% | 5–10 psi | ASTM D1056 |
| Compression Set @ 50% Deflection @ 158°F | 15% | ASTM D1056 |
Aging Performance
Oven Aging @ 168 Hours @ 158°F
| Property | Value | Test Method |
| Compression Deflection Change After Oven Aging 168 Hours @ 158°F | ±20% | ASTM D1056 |
- Cushioning pads where a firmer foam than soft grades is required for improved load support
- Anti-slip and protective padding in material handling and packaging applications where tan color is preferred
- Laminated assemblies combining natural rubber foam with textiles or cork for composite cushioning products
- Impact protection and vibration damping components requiring quick compression recovery
- Isolation and spacing pads where moderate compression resistance and high friction are required
Common industries: Consumer Products, Industrial Manufacturing, Material Handling, Packaging.
4120 is an entry-level medium firmness grade in the tan open cell natural rubber foam range, with an average density of 26 lb/ft³ and a compression deflection of 5–10 psi at 25% per ASTM D1056. It is suited for cushioning applications where a firmer foam than the 4110 soft grade is required, providing greater load-bearing resistance while retaining the anti-slip characteristics and abrasion resistance inherent to the open cell natural rubber construction. The tan color distinguishes it from the mechanically equivalent black 3120 grade.
The material features anti-slip properties and a high coefficient of friction alongside excellent resistance to abrasion and tearing. It can be laminated with a broad range of materials including textiles and cork. Compression set is 15% at 50% deflection at 158°F per ASTM D1056, and compression deflection change after oven aging at 168 hours at 158°F is ±20%. Temperature range is -20°F to 160°F.
No compliance standards are specified on the manufacturer’s TDS for this material.
What differentiates 4120 from 4110 and 4130 in the tan open cell natural rubber range, and from the black 3120?
4120 sits between the soft 4110 (2–5 psi CFD, 22 lb/ft³) and the medium-firm 4130 (10–16 psi CFD, 30 lb/ft³). At 5–10 psi CFD and 26 lb/ft³, it provides a firmer response than 4110 while remaining softer than 4130. Compared to the black 3120 grade, mechanical properties are identical — the distinction is color, with 4120 supplied in tan.
Why is compression deflection critical for open cell natural rubber foam selection?
Compression deflection at 25% defines the force required to compress the foam by a given amount — functionally its working firmness. Selecting the correct CFD ensures the material deflects adequately under load without bottoming out or providing excessive resistance to the mating surface. 4120's CFD of 5–10 psi positions it as the entry-level medium firmness option in the tan range.
What is the service temperature range for 4120?
4120 is rated from -20°F to 160°F.
Is 4120 suitable for regulated environments?
No compliance standards are specified on the manufacturer's TDS for this material.
How should 4120 be specified?
Specify grade (4120 Open Cell Natural Rubber / H-O part number 4120NRUB), thickness (1/16", 1/8", 3/16", or 1/4"), lamination requirements if applicable, dimensional tolerances, and finished format.
