Natural Rubber
(NR) | 40–80 | Approximately
−40°C to +80°C | High elastic resilience, strong vibration isolation, good fatigue resistance, and effective damping at low to medium frequencies. | Good resistance to abrasion and repeated flexing. Limited resistance to ozone, sunlight, petroleum oils, and many solvents unless specially protected. | Machinery feet, engine mounts, industrial equipment, pumps, fans, and general-purpose isolators used indoors or in protected environments. | ISO 37 for tensile properties;
ISO 48-4 for hardness;
ISO 815-1 for compression set;
ISO 10846 for transfer-mobility and dynamic-stiffness testing. | Best for high resilience and economical general-purpose isolation where oil and weather exposure are controlled. |
Chloroprene Rubber
(CR) | 40–85 | Approximately
−35°C to +100°C | Balanced damping, good mechanical strength, moderate resilience, and better weathering performance than natural rubber. | Good resistance to ozone, weather, moderate oils, and flame exposure compared with NR. Not suitable for continuous contact with many aromatic or polar solvents. | Outdoor machinery, HVAC equipment, transportation components, industrial supports, and mounts exposed to moderate weathering. | ISO 37;
ISO 48-4;
ISO 815-1;
ISO 1817 for effects of liquids;
ISO 10846 for dynamic transfer characteristics. | A practical all-round material when weather resistance and mechanical balance are more important than the lowest cost. |
Nitrile Rubber
(NBR) | 40–90 | Approximately
−30°C to +100°C | Good load-bearing capability, stable compression behavior, and strong resistance to mineral oils and fuels. | Excellent resistance to petroleum-based oils and fuels. Limited resistance to ozone, sunlight, and some aggressive chemicals unless compounded for those conditions. | Pumps, hydraulic equipment, fuel-handling systems, compressors, machine tools, and mounts near lubricants or petroleum products. | ISO 37;
ISO 48-4;
ISO 815-1;
ISO 1817 for oil and fuel immersion;
ISO 10846 for dynamic stiffness. | Preferred when oil or fuel exposure is the dominant environmental requirement. |
Ethylene Propylene Rubber
(EPDM) | 40–90 | Approximately
−45°C to +135°C | Good low-temperature flexibility, durable elastic behavior, and reliable performance under outdoor environmental exposure. | Excellent resistance to ozone, ultraviolet radiation, water, steam, and weathering. Poor compatibility with petroleum oils and fuels. | Outdoor HVAC systems, water pumps, solar equipment, building services, vehicle components, and exposed machinery. | ISO 37;
ISO 48-4;
ISO 815-1;
ISO 1817 for fluid compatibility;
ISO 10846 for vibration-isolation performance. | Strong choice for outdoor and water-related applications, provided petroleum-based oils are absent. |
Silicone Rubber
(VMQ) | 30–80 | Approximately
−60°C to +180°C | Excellent temperature flexibility, low compression set over a wide temperature range, and stable electrical insulation properties. | Very good resistance to ozone, ultraviolet radiation, and weathering. Lower tear and abrasion resistance than many organic rubbers; limited resistance to certain fuels and steam conditions. | High-temperature equipment, electronics, laboratory systems, food-processing machinery, and applications requiring wide temperature capability. | ISO 37;
ISO 48-4;
ISO 815-1;
ISO 1817 where fluid exposure is relevant;
ISO 10846 for dynamic behavior. | Select when temperature range and environmental stability are more critical than high tear strength or low material cost. |
Polyurethane
(PU) | 60–95 | Typically
−30°C to +80°C;
formulation dependent | High load capacity, strong abrasion resistance, good tear strength, and relatively high stiffness. Damping depends strongly on formulation and hardness. | Good resistance to abrasion, impact, and many oils. Hydrolysis, heat, and humidity resistance vary considerably between polyester- and polyether-based formulations. | Heavy machinery, material-handling equipment, wheels, buffers, high-load supports, and compact mounts requiring high wear resistance. | ISO 48-4 or applicable hardness method;
ISO 37 where applicable;
ISO 815-1 for compression set;
ISO 10846 for dynamic stiffness and transmissibility;
supplier-specific hydrolysis testing when required. | Confirm formulation, hydrolysis resistance, and dynamic stiffness; hardness alone does not define isolation performance. |
Metal Spring Mount
with Elastomer Interface | Not applicable to spring;
elastomer varies | Depends on spring alloy,
coating, and elastomer | High static load capacity, adjustable natural frequency, and good suitability for low-frequency isolation when correctly selected and restrained. | Metal corrosion resistance depends on alloy, plating, coating, and enclosure. Elastomer pads may limit temperature and chemical compatibility. | Chillers, air-handling units, compressors, generators, large pumps, and building-service equipment requiring substantial load support. | ISO 10846 for laboratory dynamic transfer characteristics;
ISO 10137 for vibration criteria in buildings where applicable;
material-specific corrosion and fatigue tests. | Suitable for heavy equipment and low-frequency isolation; verify lateral stability, travel limits, and seismic restraint requirements. |
Wire-Rope Isolator
(Stainless Steel Cable) | Not applicable | Commonly approximately
−70°C to +250°C;
design dependent | Multi-axis isolation, high temperature capability, strong resistance to shock and overload, and no elastomer ageing mechanism. | Good resistance to ozone, ultraviolet exposure, and many industrial environments. Corrosion performance depends on cable material and installation environment. | Marine systems, aerospace equipment, military electronics, exhaust systems, high-temperature machinery, and shock-sensitive equipment. | ISO 10846 where applicable for transfer behavior;
fatigue, shock, corrosion, and load-deflection testing according to the equipment specification. | Consider for severe temperature, shock, or chemical conditions; expect different damping behavior from elastomeric mounts. |
| Cork-Rubber Composite | Typically specified by compression behavior rather than Shore A alone | Approximately
−30°C to +120°C;
formulation dependent | Good compressive damping, low lateral creep, and useful noise-reduction performance under distributed static loads. | Moderate resistance to oils and weathering depending on binder formulation. Water absorption and long-term compression behavior require verification. | Transformers, electrical cabinets, compressors, rotating machinery, and equipment where acoustic and structural-borne noise reduction are important. | ISO 10846 for dynamic transfer behavior;
ISO 815-1 for compression set where applicable;
compression-deflection and ageing tests specified by the project. | Evaluate compression-deflection curves and long-term creep rather than selecting only by material name. |
