Rubber Types & Elastomer Guide
The most decisive factor governing seal lifespan is proper elastomer selection. Explore our 10 primary polymer groups engineered for your temperature, pressure, and chemical conditions.
Nitrile Rubber (Acrylonitrile Butadiene Rubber)
The most widely utilized elastomer for standard sealing applications. Copolymer of Butadiene and Acrylo-Nitrile (ACN).
✓ Strengths & Key Advantages
- • High resistance to aliphatic hydrocarbons (Propane, Butane, Gasoline) and petroleum derivatives
- • Excellent compatibility with mineral oils, greases, and HFA, HFB, HFC hydraulic fluids
- • Stable performance in vegetable/animal fats and light diesel fuel
- • High mechanical tensile strength, abrasion resistance, and cost efficiency
× Limitations / Weaknesses
- • Poor resistance to ozone, atmospheric weathering, and direct UV radiation
- • Unsuitable for aromatic hydrocarbons (Benzene, Toluene) and glycol-based brake fluids
Hydrogenated Nitrile Rubber (HNBR)
A high-performance elastomer produced via hydrogen saturation of NBR's butadiene double bonds.
✓ Strengths & Key Advantages
- • Extended thermal resistance up to +150°C compared to standard NBR
- • Outstanding tensile, tear, and abrasion resistance
- • Superior resistance to ozone and outdoor weathering
- • Remarkable stability against aggressive additive-laden engine and gear oils
× Limitations / Weaknesses
- • Higher raw material cost than standard NBR
- • Limited resistance to polar solvents and automotive brake fluids
Viton® / Fluoroelastomer (FKM - Fluorel)
Fluorocarbon-based elastomer representing the gold standard in high-temperature and harsh chemical sealing.
✓ Strengths & Key Advantages
- • Maintains elasticity and sealing force at continuous 225°C operating temperatures
- • Absolute resistance to synthetic lubricants, fuels, aggressive solvents, and chemicals
- • Flawless sealing under high vacuum, ozone, oxygen, and atmospheric aging
- • Inherently flame-retardant and self-extinguishing
× Limitations / Weaknesses
- • Incompatible with ketones (Acetone), esters, and amine compounds
- • Becomes rigid at extreme low temperatures (below -30°C)
Silicone Rubber (Silicone - VMQ)
Retains exceptional flexibility over an expansive thermal range; biologically inert and FDA-compliant.
✓ Strengths & Key Advantages
- • Unrivaled flexibility retention from -60°C up to +200°C
- • Outstanding resistance to ozone, UV radiation, and atmospheric aging
- • Physiologically harmless; approved for food, beverage, medical, and potable water contact
- • High dielectric electrical insulating properties
× Limitations / Weaknesses
- • Low tensile and tear resistance; not recommended for dynamic sealing
- • Poor resistance to gasoline, mineral oils, concentrated acids, and alkalis
Polyurethane (PU)
The backbone of high-pressure hydraulic sealing, providing unmatched mechanical durability and tear strength.
✓ Strengths & Key Advantages
- • Highest tensile strength, tear propagation resistance, and elastic recovery among all elastomers
- • Complete resistance to gap extrusion under extreme hydraulic pressures exceeding 400 bar
- • Excellent compatibility with mineral oils, greases, and aliphatic hydrocarbons
- • Outstanding resistance to ozone and environmental weathering
× Limitations / Weaknesses
- • Prone to hydrolysis in hot water, steam, and acidic/alkaline environments
- • Unsuitable for glycol brake fluids and aromatic solvents
Neoprene (Chloroprene Rubber - CR)
A balanced chloroprene elastomer chosen when simultaneous resistance to oils, weathering, and flames is required.
✓ Strengths & Key Advantages
- • Balanced mechanical resistance against tearing, flex fatigue, and abrasion
- • Flame-retardant with self-extinguishing properties
- • High resistance to seawater, atmospheric weathering, and ozone
- • Moderate compatibility with mineral oils and greases
× Limitations / Weaknesses
- • Inferior resistance to strong oxidizing acids and aromatic fuels
- • Shows stiffening tendencies at sub-zero temperatures
Ethylene Propylene Diene Monomer (EPDM)
Exceptional resistance to hot water, pressurized steam, brake fluids, and outdoor environmental aging.
✓ Strengths & Key Advantages
- • Outstanding durability in hot water and 150°C pressurized steam
- • Full compatibility with glycol-based automotive brake fluids (DOT 3, DOT 4, DOT 5.1)
- • Flawless resistance to ozone, atmospheric exposure, and ultraviolet light
- • Resistant to phosphate ester fire-resistant hydraulic fluids (Skydrol)
× Limitations / Weaknesses
- • STRICTLY INCOMPATIBLE with mineral oils, greases, and petroleum fuels (causes severe swelling)
Teflon® / Polytetrafluoroethylene (PTFE)
Chemically inert fluoroplastic exhibiting the lowest coefficient of friction among all solid materials.
✓ Strengths & Key Advantages
- • Unrivaled operational range from cryogenic -200°C to +260°C
- • Zero chemical reactivity with virtually all acids, bases, solvents, and aggressive reagents
- • Permanent self-lubricating surface (eliminates stick-slip motion)
- • Full compliance with FDA standards for food and pharmaceutical contact
× Limitations / Weaknesses
- • Non-elastic thermoplastic subject to cold flow / creep; requires precision housing design
Polyoxymethylene / Polyacetal (Delrin - POM)
Rigid, dimensionally stable engineering thermoplastic engineered to eliminate metal-on-metal friction.
✓ Strengths & Key Advantages
- • High mechanical rigidity, tensile strength, and impact toughness
- • Extremely low moisture absorption with micron-level dimensional stability
- • Completely non-corrosive in hydraulic guide bush and wear ring applications
- • Superb chemical resistance to oils and hydrocarbons
× Limitations / Weaknesses
- • Limited resistance against concentrated acids and strong oxidizing chemicals
Natural Rubber (NR)
Harvested from Hevea trees, delivering incomparable mechanical elasticity and dynamic fatigue endurance.
✓ Strengths & Key Advantages
- • Highest elasticity, tensile resilience, and elongation at break
- • Maintains flexible rebound at extreme low temperatures
- • Unrivaled shock absorption and vibration damping capacity
× Limitations / Weaknesses
- • Vulnerable to petroleum oils, fuels, ozone, and sustained high temperatures