ECO
also Hydrin
ECO is an epichlorohydrin-ethylene oxide copolymer (Hydrin family, with CO homopolymer and GECO terpolymer variants) that combines fuel and oil resistance with a glass transition near -40 °C.
Reference datasheet — ECO is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ECO-CO condition
ECO grades and fills
ECO is supplied in 9 conditions, soft to hard. ECO-CO is the default FabDigit quotes; the values on this page are for it.
Compare all 9 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Shore A 50 | Soft diaphragms, bellows and low-clamp-force gaskets. | 9 | 400 | 12 Shore D | |
Conductive / antistatic grade | Choose for fuel hose liners that must dissipate static charge per SAE J30/J2260 requirements. | 10 | 220 | 23 Shore D | |
GECO / ETER | Use where sulfur or peroxide cure, lower compression set and the best low-temperature flexibility are required. | 11 | 280 | 18 Shore D | |
Shore A 60 | Hose inner liners and flexible fuel-system components. | 11 | 320 | 16 Shore D | |
Peroxide-cured GECO compound | Pick for static seals needing low compression set and no lead/thiourea cure residues. | 11 | 230 | 22 Shore D | |
ECO-CODefault ECO | Standard choice for fuel and vacuum hose, diaphragms and seals needing oil resistance plus −40 °C flexibility. | 12 | 250 | 22 Shore D | |
Shore A 70 | Default seal/O-ring and hose hardness; best balance of strength and set. | 12 | 250 | 22 Shore D | |
Epichlorohydrin homopolymer | Pick when the lowest gas/fuel permeability and best hydrocarbon resistance matter more than cold flexibility. | 13 | 220 | 22 Shore D | |
Shore A 80 | Higher-pressure seals, backup rings and stiff mount elements. | 13 | 180 | 30 Shore D |
What is ECO?
ECO is an epichlorohydrin-ethylene oxide copolymer (Hydrin family, with CO homopolymer and GECO terpolymer variants) that combines fuel and oil resistance with a glass transition near -40 °C. Density is about 1.36 g/cm³, tensile strength 12 MPa, elongation 250 % and maximum service temperature 125 °C, and the polymer is inherently semi-conductive so antistatic grades are available. It is used for fuel and vacuum hose, seals and cold-service gaskets. Compounds are scorch-sensitive and need an acid acceptor, and cost is above NBR, which is the usual substitute when -40 °C flexibility is not required. ECO has a density of 1.36 g/cm³ (0.0491 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is -40°C (-40 °F). ECO has a tensile strength of 12 MPa (1.74 ksi), weaker than 76% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.01 GPa (8.7×10⁻⁴ Msi).
What is ECO used for?
- fuel hoses
- vacuum hoses
- automotive seals
- low-temp gaskets
Advantages
- Good UV / weathering resistance — 88/100, better than 90% of polymer grades
- Forms and bends easily — 85/100, better than 81% of polymer grades
- Ductile — tolerates forming and impact — 250%, better than 79% of polymer grades
Limitations
- Difficult to machine — 25/100, worse than 93% of polymer grades
- Absorbs moisture — dry before molding — 1.5%, worse than 91% of polymer grades
- High mold shrinkage — 2.3%, worse than 89% of polymer grades
- Low stiffness — 0.01 GPa (8.7×10⁻⁴ Msi), worse than 86% of polymer grades
- Difficult to weld — 10/100, worse than 82% of polymer grades
ECO properties
Typical room-temperature values for ECO-ECO-CO; bars are the position among polymer grades.
Physical4
ECO has a density of 1.36 g/cm³ (0.0491 lb/in³), heavier than 75% of polymer grades. Its glass-transition temperature is -40°C (-40 °F).
Mechanical8
ECO has a tensile strength of 12 MPa (1.74 ksi), weaker than 76% of polymer grades. Elongation at break is 250% and the elastic modulus is 0.01 GPa (8.7×10⁻⁴ Msi).
Thermal8
ECO is rated for continuous service to 125°C (257 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 180 µm/m·K (100 µin/in·°F).
Electrical4
ECO is an electrical insulator with a dielectric strength of 16 kV/mm (406.4 V/mil) and a resistivity of 1×10⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (78/100), worse than 61% of polymer grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of ECO takes about 115 MJ of energy and emits 4.8 kg of CO₂ — more than 70% of polymer grades. Typical recycled content is 0%.
Manufacturability5
ECO's machinability is poor (25/100, worse than 93% of polymer grades); weldability not recommended (10/100); formability excellent (85/100).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. ECO is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ECO
Is ECO easy to machine?
Cured ECO is best die-cut, water-jet or cryo-deflashed; grinding/turning needs sharp tools and freezing to avoid tearing and smearing.
Can ECO be welded?
Not weldable as a thermoset; joints are made by adhesive bonding (cyanoacrylate/epoxy on chlorinated-primer or plasma-treated surfaces) or by co-vulcanization during molding.
Can ECO be formed, bent or molded?
Mills and extrudes easily but is tacky and scorch-sensitive; compression/injection cure at 160–190 °C with an MgO-type acid acceptor, and post-cure 2–4 h at 150 °C for lowest compression set.
ECO chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| epichlorohydrin (ECH) unitschlorine-bearing repeat unit; ~30–38 wt% Cl in CO homopolymer | 55 – 75 | 68 |
| ethylene oxide (EO) unitsraises low-temperature flexibility, absent in CO homopolymer | 25 – 45 | 32 |
| allyl glycidyl ether (AGE)cure-site monomer, present only in GECO/ETER terpolymer | 0 – 8 | 0 |
| carbon black (N550/N774)phr in a typical 70 Shore A compound | 30 – 70 | 50 |
| plasticizer / process oil (ether-ester tphr | 0 – 20 | 8 |
| acid acceptor (MgO / hydrotalcite) + curphr; acid acceptor essential to trap evolved HCl | 3 – 10 | 6 |
What surface finishes work on ECO?
Usually used as-molded in black; surfaces can be talc- or PTFE-dusted, plasma- or chlorine-treated for low friction, and adhesion to brass/steel inserts is achieved with standard rubber-to-metal bonding agents.
Equivalent designations
Standards and trade names that resolve to ECO in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Hydrin
How much does ECO cost?
ECO is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ECO — frequently asked
What is ECO used for?
ECO is typically used for fuel hoses, vacuum hoses, automotive seals and low-temp gaskets. In short: fuel resistance to -40 °C; inherently antistatic elastomer; low permeability to fuels.
What is the tensile strength of ECO?
ECO has a typical tensile strength of 12 MPa (1.74 ksi) — weaker than 76% of polymer grades. Strength varies by condition: see the 9 listed tempers.
Is ECO easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of polymer grades). Cured ECO is best die-cut, water-jet or cryo-deflashed; grinding/turning needs sharp tools and freezing to avoid tearing and smearing.
Can ECO be welded?
Not readily — weldability is rated not recommended (10/100). Not weldable as a thermoset; joints are made by adhesive bonding (cyanoacrylate/epoxy on chlorinated-primer or plasma-treated surfaces) or by co-vulcanization during molding.
What surface finishes work on ECO?
Usually used as-molded in black; surfaces can be talc- or PTFE-dusted, plasma- or chlorine-treated for low friction, and adhesion to brass/steel inserts is achieved with standard rubber-to-metal bonding agents.
Can ECO be formed, bent or molded?
Mills and extrudes easily but is tacky and scorch-sensitive; compression/injection cure at 160–190 °C with an MgO-type acid acceptor, and post-cure 2–4 h at 150 °C for lowest compression set.
What is the maximum service temperature of ECO?
ECO is rated for continuous use to about 125°C (257 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does ECO cost?
ECO is a high-cost polymer ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Hydrin CO/ECO/ETER epichlorohydrin elastomer technical bulletins — Zeon Chemicals (2021)
- Engineered Materials Handbook Vol.2: Engineering Plastics / Rubber Products Manufacturing Technology — ASM International (1988)
- ASTM D2000 — Classification System for Rubber Products in Automotive Applications (type/class CH, CE) — ASTM (2020)
- ISO 1629 — Rubber and latices: nomenclature (CO, ECO, GECO) — ISO (2013)
- SAE J30 / SAE J2260 — Fuel and vapour hose requirements — SAE International (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.