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Rubber & Elastomers•Oil & Fuel Resistant Elastomers•
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Hydrogenated Nitrile Rubber (HNBR)

Primary Designation:ASTM HNBR
Aliases:
Highly Saturated NitrileHSNTherbanZetpol

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Data Completeness:0 composition elements and 7 condition-specific property values cataloged.
Omitted fields represent unverified properties. "Missing is better than invented."

Key Engineering Properties

Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.

Density
1 g/cm³TYPICAL · Standard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated) · temperature not stated
Hardness (Shore A)
50 – 90 Shore ARANGE · Standard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated) · temperature not stated
ASTM D2240 / ISO 48-4
Tensile Strength
15 – 30 MPaRANGE · Standard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated) · at 23 °C
Service Temp Range
-40°C to 150°CContinuous Limit
Continuous service typically -40°C to +1...

Engineering Summary

Hydrogenated Nitrile Butadiene Rubber (HNBR)—also known as Highly Saturated Nitrile (HSN)—is produced by catalytic hydrogenation of the butadiene double bonds in NBR. Hydrogenation eliminates the unsaturation responsible for oxidative and ozone breakdown while preserving the polar acrylonitrile groups responsible for oil resistance. HNBR bridges the performance gap between NBR and fluoroelastomers (FKM), providing continuous service temperatures up to +150°C, outstanding mechanical strength (tensile strength up to 30 MPa), superior wear resistance, and exceptional resistance to ozone cracking and sour gas (H₂S) in petroleum extraction.

Hydrogenated Nitrile Rubber (HNBR) Documented Applications

  • ›Automotive heavy-duty timing belts, serpentine drive belts, and variable transmission belts
  • ›High-temperature automotive air conditioning O-rings and R134a/R1234yf compressor seals
  • ›Oil and gas downhole drilling packers, blowout preventers, and sour gas (H₂S) wellhead seals
  • ›High-pressure diesel common-rail fuel injector seals and marine engine gaskets
  • ›Aerospace dynamic hydraulic actuator seals exposed to synthetic hydrocarbon lubricants

Recognized Aliases

Source-backed commercial trade name and short designations cataloged in canonical data.

Highly Saturated NitrileHSNTherbanZetpol

Elastomer Technical Profile • Hydrogenated Nitrile Rubber (HNBR)

ASTM D1418: HNBRISO 1629: HNBRASTM D2000: Type DH

Polymer backbone: Hydrogenated acrylonitrile-butadiene copolymer. Thermoset and cast elastomer mechanical, thermal, and chemical behavior depends strongly on compounding ingredients, crosslink density, and curing system.

Key Engineering Advantages

  • •Exceptional continuous thermal resistance up to 150°C (302°F), with intermittent peaks to 160°C
  • •Outstanding resistance to atmospheric ozone and oxidative heat embrittlement
  • •Highest tensile strength (up to 30 MPa) among oil-resistant industrial thermoset rubbers
  • •High resistance to sour gas (hydrogen sulfide, H₂S), amines, and aggressive oilfield additives in properly formulated peroxide cures
  • •Superior dynamic wear and tooth-shear resistance in high-torque synchronous timing belts

Engineering Limitations & Risks

  • •Higher raw material cost than standard NBR, SBR, and EPDM elastomers
  • •Incompatible with polar solvents including ketones (MEK, acetone), esters, and strong oxidizing acids
  • •Requires peroxide cure systems and specialized mold release due to stickiness during cure
  • •Low-temperature limit is governed by ACN content; standard grades stiffen below -30°C

Thermal Operating Limits & Service Profile

Min Continuous-40°C
Max Continuous150°C
Max Intermittent / PeakNot specified

Note: Continuous service typically -40°C to +150°C (-40°F to +302°F) per Zeon Zetpol Technical Manual (Tables 2 & 5) and Parker ORD 5700. ASTM D2000 Type DH callouts specify 70h accelerated heat aging at 150°C for material classification rather than defining continuous operational service limits.

Chemical & Environmental Media Compatibility (Engineering Selection Guide)

Parker ORD 5700 Selection Ratings
Ratings represent manufacturer engineering fluid selection guidance (Parker ORD 5700 / producer design manuals). They do not substitute for batch-specific ASTM D471 / ISO 1817 laboratory immersion testing under service temperature, pressure, and dynamic stress.
Petroleum Engine & Gear OilsSuperior retention of elongation and tensile properties in hot mineral lubricants
EXCELLENT
Sour Gas (H₂S Environments)High resistance to sour gas (H₂S) embrittlement; performance is compound-dependent, requiring highly saturated peroxide-cured formulations per Zeon Zetpol manual
EXCELLENT
Atmospheric Ozone & WeatheringHydrogenated backbone eliminates diene double bonds vulnerable to ozone attack
EXCELLENT
Automotive Fuels & BiofuelsResistant to gasoline, diesel, and ethanol fuel blends (E10 to E85)
GOOD
Water & Steam (up to 130°C)Significantly more resistant to hot water and steam than standard NBR
GOOD
Ketones & Strong SolventsSevere swelling in MEK, acetone, and chlorinated hydrocarbons
NOT RECOMMENDED

Compounding & Physical Property Context

Compounding Dependency: Properties are dictated by both ACN level (typically 34% to 44%) and the degree of residual double-bond unsaturation (typically 0.5% to 5.5%). Lower residual unsaturation gives maximum heat and ozone resistance; slightly higher residual unsaturation enables sulfur vulcanization and better dynamic adhesion to tire cords.

Gas & Fluid Permeability: Very low gas and fuel permeability, comparable to high-ACN NBR and significantly lower than silicone or EPDM.

Abrasion Endurance: Outstanding dynamic abrasion and tooth-shear fatigue resistance; standard material for automotive timing belts surviving 150,000+ miles.

Tear Resistance: Typical ASTM D624 Die C tear strength 35–65 kN/m with superior cut-growth resistance under high cyclic shear stress. (Not directly comparable to trouser tear Die T).

Compression Set (ASTM D395): Low compression set at elevated temperatures (15–28% at 125°C) when formulated with peroxide cure packages.

Hydrogenated Nitrile Rubber (HNBR) Specifications & Designations

Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.

Direct Standard DesignationsDIRECT DESIGNATION
3 Primary Identifiers
Scroll horizontally for full designation data
SystemIdentifierStandard System NameClassification Notes & Provenance
ASTMPRIMARYHNBRASTM D1418 Nomenclature—Ref: Standard Practice for Rubber and Rubber Latices—Nomenclature (ASTM D1418-22) / Rubber and latices—Nomenclature (ISO 1629:2013)
ISOHNBRISO 1629 Nomenclature—Ref: Standard Practice for Rubber and Rubber Latices—Nomenclature (ASTM D1418-22) / Rubber and latices—Nomenclature (ISO 1629:2013)
ASTM-D2000Type DHASTM D2000 Classification SystemClassified under ASTM D2000 as Type DH (defined by 70h accelerated heat-aging test at 150°C with low oil swell in ASTM IRM 903 oil; accelerated test temperatures serve classification and do not constitute continuous service ratings).Ref: Standard Classification System for Rubber Products in Automotive Applications (ASTM D2000-21 / SAE J200:2021)
Recognized Commercial Aliases & Trade NamesCOMMON ALIAS
4 Listed
Scroll horizontally for full alias classifications
Recognized Name / AliasClassificationTechnical Usage & Context
Highly Saturated NitrileCommercial AliasColloquial or commercial industry synonym
HSNColloquial AliasColloquial or commercial industry synonym
TherbanCommercial AliasColloquial or commercial industry synonym
ZetpolCommercial AliasColloquial or commercial industry synonym
Applicable Specifications & Product Form ReferencesSPECIFICATION REFERENCE
3 Applicable Standards
Scroll horizontally for full standard specifications
Standards BodySpecification CodeSpecification Title / ScopeRelationship Type
ASTM InternationalASTM D1418Standard Practice for Rubber and Rubber Latices—NomenclatureSTANDARD · Edition: ASTM D1418-22Specification Reference
ISOISO 1629Rubber and latices — NomenclatureSTANDARD · Edition: ISO 1629:2013Specification Reference
ASTM InternationalASTM D2000Standard Classification System for Rubber Products in Automotive ApplicationsSTANDARD · Edition: ASTM D2000-21Specification Reference
Engineering Notice: Applicable specifications establish manufacturing requirements, dimensional tolerances, and test criteria for specific product forms (e.g. bus bar, wire, plate, pipe). They represent applicable technical standards, not alternative or equivalent alloy grades.
Property Display UnitsSwitch between Canonical SI and Source / US Customary units:

Hydrogenated Nitrile Rubber (HNBR) Physical Properties

Source-specific physical properties. Test temperatures are shown only where reported.

2 Parameters
Scroll horizontally for full property parameters
Property ParameterCanonical SI ValueSemantic BasisTest Temperature / Context RangeSource Raw ReferenceSource ReferenceStatus
Density (Raw Copolymer Base)Condition: Standard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated)1 g/cm³TYPICALUnpigmented raw hydrogenated polymer base density.1.00 g/cm³ASTM International, ISO & Elastomer Engineering Technical CommitteesVERIFIED
Density (Cured Industrial Compound)Condition: Standard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated)1.15 – 1.3 g/cm³RANGECompounded density with carbon black or silica reinforcing fillers.1.15 – 1.30 g/cm³ASTM International, ISO & Elastomer Engineering Technical CommitteesVERIFIED

Hydrogenated Nitrile Rubber (HNBR) Mechanical Properties

Contextual Mechanical Properties & Tempers: Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.

Showing 4 of 4 conditions
Scroll horizontally for all conditions & tempers
Product FormTemper / ConditionSection SizeTensile (UTS)Yield StrengthElongationShear StrengthFatigue StrengthHardness (Scales Preserved)Status
Standard Product FormStandard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated) · 23 °C
Source values and qualifiers
Tensile Strength (Break): 15–30 MPa (RANGE)Significantly higher tensile strength than standard NBR and FKM.ASTM D412 / ISO 37Zeon Chemicals L.P. — Zeon Chemicals L.P. Technical Report ZP-2021, Tables 2 & 5 (Thermal Envelope & ASTM D2000 Type DH Callouts, ASTM D624 Die C Tear Strength) / ASTM D1418 HNBR
Ultimate Elongation at Break: 200–500 % (RANGE)High elongation retained even after prolonged exposure to elevated temperatures.ASTM D412 / ISO 37Zeon Chemicals L.P. — Zeon Chemicals L.P. Technical Report ZP-2021, Tables 2 & 5 (Thermal Envelope & ASTM D2000 Type DH Callouts, ASTM D624 Die C Tear Strength) / ASTM D1418 HNBR
—15–30 MPa—200–500 %———VERIFIED
Standard Product FormStandard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated) · 23 °C
Source values and qualifiers
Tear Resistance: 35–65 kN/m (RANGE)ASTM D624 Die C tear strength measuring initiation and propagation across a 90° angle. Values are not directly comparable to trouser tear (ASTM D624 Die T / ISO 34-1 Method A) or crescent dies (Die B).ASTM D624 Die C / ISO 34-1Zeon Chemicals L.P. — Zeon Chemicals L.P. Technical Report ZP-2021, Tables 2 & 5 (Thermal Envelope & ASTM D2000 Type DH Callouts, ASTM D624 Die C Tear Strength) / ASTM D1418 HNBR
———————VERIFIED
Standard Product FormStandard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated) · 125 °C
Source values and qualifiers
Compression Set (22h at 125°C): 15–28 % (RANGE)Peroxide-cured HNBR maintains low compression set at temperatures where NBR degrades.ASTM D395 Method B / ISO 815-1Zeon Chemicals L.P. — Zeon Chemicals L.P. Technical Report ZP-2021, Tables 2 & 5 (Thermal Envelope & ASTM D2000 Type DH Callouts, ASTM D624 Die C Tear Strength) / ASTM D1418 HNBR
———————VERIFIED
Standard Product FormStandard Peroxide-Cured 70 Shore A Compound (Fully Hydrogenated)
Source values and qualifiers
SHORE_A Hardness: 50–90 SHORE_A (RANGE)70 Shore A for standard fluid seals; 80–90 Shore A for high-pressure downhole packers.Durometer Type A per ASTM D2240 / ISO 48-4 at 23°C.Zeon Chemicals L.P. — Zeon Chemicals L.P. Technical Report ZP-2021, Tables 2 & 5 (Thermal Envelope & ASTM D2000 Type DH Callouts, ASTM D624 Die C Tear Strength) / ASTM D1418 HNBR
——————
50–90 SHORE_A
VERIFIED
Hardness Integrity Notice: Rockwell B (HRB), Rockwell F (HRF), and Superficial 30T (HR30T) scales are reported on their measured scales without cross-scale mathematical conversion.
Source: See fact-level citations

Hydrogenated Nitrile Rubber (HNBR) Processing & Fabrication

Machining, joining, forming, and thermal processing ratings cataloged from the cited authoritative technical reference.

Source: Zeon Chemicals L.P.

Machinability

Cryogenically machined with liquid nitrogen; precision waterjet cutting yields clean seal cross-sections without thermal scorch.

Heat Treatment & Working Ranges

Peroxide-cured (typically with co-agents such as TAC or TMPTM) at 160°C to 180°C to generate high carbon-carbon crosslink density for maximum thermal stability.

Forming & Cold Working

High Mooney viscosity requires high-shear internal mixing. Moldable via high-pressure compression, transfer, and injection molding with vacuum de-airing.

Hydrogenated Nitrile Rubber (HNBR) Equivalent & Comparable Grades

Comparable Grades & Cross-References: Carefully classified cross-reference relationships for Hydrogenated Nitrile Rubber (HNBR). Comparable does not mean equivalent.

Scroll horizontally for relationship classifications & comparisons
Related MaterialFamilyRelationship ClassificationMetallurgical Notes & DifferencesStatusAction
Nitrile Butadiene Rubber (NBR)rubber-and-elastomersNearest AlternativeHNBR upgrades NBR with +50°C higher temperature capability, exceptional ozone resistance, and greater tensile strength.Design parameters (weldability, hardenability, fatigue limit) must be re-evaluated for the specific application.VERIFIEDSide-by-Side Compare →
Fluoroelastomer (FKM)rubber-and-elastomersCommonly ComparedHNBR provides superior mechanical toughness, tear resistance, and dynamic abrasion over FKM; FKM provides higher continuous heat resistance (+200°C) and broader chemical resistance.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost).VERIFIEDSide-by-Side Compare →

Related Engineering & Metallurgy Guides

Contextual technical guides explaining degradation mechanisms, testing methodologies, and selection criteria relevant to Hydrogenated Nitrile Rubber (HNBR).

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What is EPDM Rubber? Properties, Chemistry, Roofing vs Engineering Specifications

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NBR vs EPDM: Oil Resistance, Weathering, Temperature & O-Ring Selection Guide

NBR and EPDM represent the two most widely specified synthetic elastomers in modern mechanical engineering, yet their chemical compatibility profiles are almost perfectly inverse. Specifying NBR in outdoor steam service leads to rapid embrittlement, while installing EPDM in a petroleum oil loop causes catastrophic volume swell and joint blowout. This guide provides the thermodynamic principles and engineering decision trees required to make the right choice.

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Natural Rubber vs Synthetic Rubber: Resilience, Fatigue, Chemistry & Industrial Trade-offs

Despite over a century of synthetic polymer synthesis, natural rubber remains indispensable in modern heavy engineering. Its unique ability to undergo instantaneous strain-induced crystallization grants it dynamic tear strength and fatigue endurance that synthetic random copolymers cannot replicate. However, when service conditions introduce petroleum fuels, atmospheric ozone, or temperatures exceeding 80°C, synthetic elastomers become mandatory. This guide examines the macromolecular physics and industrial trade-offs governing selection.

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Sources

Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.

ASTM International, ISO & Elastomer Engineering Technical CommitteesZetpol® Hydrogenated Nitrile Elastomer Engineering Technical Manual
STANDARDS ORG

Producer technical manual detailing hydrogenated nitrile butadiene rubber (HNBR) thermal limits up to +150°C continuous, sour gas H₂S resistance, and peroxide cure characteristics.

Issuing Body: Zeon Chemicals L.P.Revision: 2021 RevisionView Source Record ↗
ASTM International, ISO & Elastomer Engineering Technical CommitteesStandard Practice for Rubber and Rubber Latices—Nomenclature (ASTM D1418-22) / Rubber and latices—Nomenclature (ISO 1629:2013)
STANDARDS ORG

Authoritative international nomenclature defining rubber acronyms and classification families.

Issuing Body: ASTM International & ISO Technical Committee ISO/TC 45 (Rubber and Rubber Products)Revision: ASTM D1418-22 / ISO 1629:2013View Source Record ↗
ASTM International, ISO & Elastomer Engineering Technical CommitteesStandard Classification System for Rubber Products in Automotive Applications (ASTM D2000-21 / SAE J200:2021)
STANDARDS ORG

Standardized classification system establishing Type and Class designations and line callouts for vulcanized rubber compounds.

Issuing Body: ASTM International & SAE International Technical CommitteesRevision: ASTM D2000-21View Source Record ↗
Intellectual Property & Provenance Notice: Mat Grades cites technical literature from recognized industry associations and standards organizations. Underlying technical standards and publication data remain the intellectual property of their respective issuing organizations.