Standards index

What each standard is for and why a buyer or specifier might ask for it. Summaries are our own words. Confirm the current edition before you quote one.

ASTM D2240

Durometer hardness

Measures indentation hardness of rubber with a spring-loaded durometer. Shore A is used for most seal compounds; Shore D for harder materials.

First number on any datasheet; easy to check at goods-in.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 48-4

Hardness by durometer (Shore)

ISO route to Shore hardness for rubber, comparable to ASTM D2240 in principle.

Used on export orders that follow ISO method sets.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 48-2

Hardness in IRHD

Hardness in international rubber hardness degrees, measured with a small ball indenter. Common on O-rings and small cross-sections.

Needed when the part is too small for a durometer foot.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D412

Tensile properties

Pulls dumbbell or ring specimens to break and reports tensile strength, elongation at break and stress at set elongations (modulus).

The base data set for every compound.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 37

Tensile properties

ISO equivalent of ASTM D412, with its own specimen shapes and speeds.

Used with ISO-based customer specs.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D624

Tear strength

Measures resistance of vulcanised rubber to tear growth using notched or nicked specimens.

Important for parts that are stretched over hardware or demoulded with undercuts.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 34-1

Tear strength

ISO tear test using trouser, angle or crescent specimens.

ISO counterpart to ASTM D624.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D395

Compression set

Squeezes a rubber disc or button for a set time at temperature, then measures how much thickness is not recovered. Method B (constant deflection) is the usual seal test.

The best single indicator of long-term sealing force retention; sensitive to cure and post-cure.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 815-1

Compression set (ambient and high temperature)

ISO method for compression set at ambient or elevated temperature.

Compare only values made with the same method, deflection and specimen size.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D1414

O-ring testing

Defines test procedures that apply to finished O-rings, including compression set and tensile data on rings.

Allows testing of the part rather than a plaque.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D2632

Rebound resilience

Measures how much energy a rubber returns when struck by a falling plunger.

Useful for screening cure state and polymer type.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D297

Rubber products chemical analysis

A set of wet-chemical and gravimetric methods for analysing the composition of rubber products, including extractables, ash, carbon black and polymer fraction.

Core of reverse-engineering work.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D792

Density and specific gravity

Weighs a specimen in air and in liquid to get density. Plastics-focused, widely used for rubber too.

Check on every batch; a quick sign of mixing errors.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 2781

Density of rubber

ISO method for density of vulcanised rubber.

ISO counterpart for batch checks.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ISO 23529

Preparation and conditioning of test pieces

General rules for preparing, conditioning and measuring rubber test pieces.

Reduces scatter between labs.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D3182

Mixing and preparing standard test sheets

Describes equipment and procedures for mixing standard test compounds and moulding standard vulcanised sheets.

Foundation for lab mixing and plaque preparation.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D3183

Preparing test pieces from products

Covers cutting test pieces out of finished rubber products.

Used when only a finished part is available.

Physical and mechanical

Confirm the current edition and any amendments before quoting it.

ASTM D1646

Mooney viscosity and scorch

Measures the viscosity and early cure (scorch) of raw rubber or compounds in a rotating-disc viscometer.

Describes how a compound will flow and how long it is safe to process.

Processing and cure

Confirm the current edition and any amendments before quoting it.

ISO 289-1

Mooney viscosity

ISO method for Mooney viscosity.

ISO counterpart to ASTM D1646.

Processing and cure

Confirm the current edition and any amendments before quoting it.

ASTM D5289

Cure characteristics (rotorless rheometer)

Measures torque against time on a sample in a heated, oscillating cavity. Gives ML, MH, scorch time and t90.

The standard cure-curve for batch release; central to Pascalor batch records.

Processing and cure

Confirm the current edition and any amendments before quoting it.

ISO 6502-3

Cure characteristics (rotorless curemeters)

ISO method for rotorless rheometers.

ISO counterpart to ASTM D5289.

Processing and cure

Confirm the current edition and any amendments before quoting it.

ISO 3417

Oscillating-disc rheometer

ISO method for the older oscillating-disc type of curemeter.

Seen in older specifications.

Processing and cure

Confirm the current edition and any amendments before quoting it.

ASTM D573

Heat ageing in an air oven

Ages rubber test pieces in a hot-air oven for a set time and temperature, then compares properties with unaged values.

The basic heat-resistance screen.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ISO 188

Accelerated ageing and heat resistance tests

ISO hot-air ageing method.

ISO counterpart to ASTM D573.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ISO 11346

Estimating life and maximum use temperature

Guidance for extrapolating long-term ageing behaviour from tests at several temperatures.

Useful for service-life claims; extrapolation has limits and should be stated.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ASTM D1329

Low-temperature retraction (TR test)

Stretches a specimen, freezes it, then lets it warm up and records the temperature at which it retracts by 10%, 30%, 50% and 70%.

TR10 is the figure many polymer datasheets quote for low-temperature capability.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ISO 2921

Low-temperature retraction (TR test)

ISO version of the retraction test.

ISO counterpart to ASTM D1329.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ASTM D2137

Brittleness temperature

Finds the temperature at which rubber specimens fracture when struck.

Gives a lower limit than retraction tests.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ASTM E1356

Glass transition by DSC

Determines the glass transition temperature of a material by differential scanning calorimetry.

Identifies polymer type and low-temperature behaviour.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ISO 22768

Glass transition of raw rubber by DSC

ISO method for Tg of raw rubbers by DSC.

Used in reverse engineering to confirm polymer type.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ASTM D1149

Ozone cracking

Exposes strained rubber specimens to ozone and records crack formation.

Relevant for outdoor and electrical uses; fluoro-rubbers and HNBR are usually good performers.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ISO 1431-1

Ozone cracking

ISO method for ozone resistance of strained rubber.

ISO counterpart to ASTM D1149.

Temperature and ageing

Confirm the current edition and any amendments before quoting it.

ASTM D471

Effect of liquids

Immerses rubber in a liquid at set temperature and time and records changes in mass, volume, hardness, tensile and elongation. Defines reference oils IRM 901/902/903 and reference fuels.

The standard route to fluid-resistance data on seal compounds.

Fluid resistance

Confirm the current edition and any amendments before quoting it.

ISO 1817

Effect of liquids

ISO immersion method with similar principles to ASTM D471.

ISO counterpart.

Fluid resistance

Confirm the current edition and any amendments before quoting it.

ISO 13226

Standard reference elastomers for liquid effects

Defines reference elastomers used to characterise how test liquids affect rubber.

Used to qualify reference fluids.

Fluid resistance

Confirm the current edition and any amendments before quoting it.

ASTM D1418

Rubber nomenclature

Gives the standard abbreviations for rubbers. FKM, HNBR and FEPM designations come from here.

Use these codes in specifications.

Classification and nomenclature

Confirm the current edition and any amendments before quoting it.

ISO 1629

Rubber nomenclature

ISO list of rubber abbreviations, equivalent in purpose to ASTM D1418.

Classification and nomenclature

Confirm the current edition and any amendments before quoting it.

ASTM D2000

Rubber products classification (line callout)

A coded callout system that describes a rubber material by type, class, hardness, tensile and further requirements. Equivalent to SAE J200.

A single line can describe a compound; widely used for procurement.

Classification and nomenclature

Confirm the current edition and any amendments before quoting it.

SAE J200

Rubber materials classification

SAE version of the ASTM D2000 classification.

Used on automotive and fluid-power drawings.

Classification and nomenclature

Confirm the current edition and any amendments before quoting it.

ASTM D1765

Carbon black classification

The N-number classification system for carbon blacks used in rubber, such as N550, N774 and N990.

Needed to specify the black in a recipe.

Classification and nomenclature

Confirm the current edition and any amendments before quoting it.

ASTM D3677

Rubber identification by infrared

Identifies the polymer in a rubber by infrared spectroscopy.

Often the first step in reverse engineering.

Composition and identification

Confirm the current edition and any amendments before quoting it.

ISO 4650

Rubber identification by infrared

ISO infrared identification method.

ISO counterpart.

Composition and identification

Confirm the current edition and any amendments before quoting it.

ASTM D3452

Rubber identification by pyrolysis-GC

Identifies rubber by pyrolysing it and analysing the vapour by gas chromatography.

Complements IR, especially for blends and filled compounds.

Composition and identification

Confirm the current edition and any amendments before quoting it.

ASTM D6370

Compositional analysis by TGA

Uses thermogravimetric analysis to measure volatile, polymer, carbon black and ash fractions.

Quick, repeatable composition screen.

Composition and identification

Confirm the current edition and any amendments before quoting it.

ISO 9924

Composition of vulcanisates by TGA

A multi-part ISO series that uses thermogravimetry to find the composition of vulcanised and uncured rubber. Which part applies depends on the rubber type, so check that the part covers fluoro-rubbers or HNBR before relying on it.

ISO route comparable to ASTM D6370.

Composition and identification

Confirm the current edition and any amendments before quoting it.

ASTM D5992

Dynamic testing guide

Guide for dynamic testing of vulcanised rubber.

Applies to dynamic seals and damping parts.

Composition and identification

Confirm the current edition and any amendments before quoting it.

ISO 4664-1

Dynamic properties (guidance)

General guidance on determining dynamic properties of rubber.

ISO counterpart for DMA planning.

Composition and identification

Confirm the current edition and any amendments before quoting it.

NORSOK M-710

Qualification of non-metallic sealing materials and manufacturers

Norwegian industry standard that sets out a qualification route for sealing materials, including rapid gas decompression and ageing tests.

The best-known RGD requirement for offshore sealing elastomers.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it. Check the revision cited by the operator.

ISO 23936-2

Non-metallic materials in oil and gas production, Part 2: Elastomers

International standard describing how to qualify elastomers for oil and gas service, including ageing in test media and rapid gas decompression. Closely related to NORSOK M-710.

A common basis for operator and manufacturer qualification programmes.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

ISO 23936-1

Non-metallic materials in oil and gas production, Part 1: Thermoplastics

Companion standard for thermoplastics.

Reference only; not for elastomers.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

API 6A / ISO 10423

Wellhead and Christmas tree equipment

Specification for wellhead and tree equipment. It sets design, material and testing requirements that include non-metallic seals and temperature ratings.

Seal compounds in this equipment are normally supplied against the equipment maker's own qualification.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

API 16A / ISO 13533

Drill-through equipment

Specification for blowout preventers and related drill-through equipment, which use elastomer sealing elements.

Elastomer packers and seals are qualified by equipment makers.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

API 17D / ISO 13628-4

Subsea wellhead and tree equipment

Specification for subsea wellhead and tree equipment.

Subsea sealing materials are normally qualified through operator and equipment-maker programmes.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

API 6D / ISO 14313

Pipeline and piping valves

Specification for pipeline valves, including requirements for soft seals.

Valve-seat and stem seals.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

API 17J

Unbonded flexible pipe

Specification for unbonded flexible pipe, which uses polymers and elastomers in the structure.

Reference only.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

NACE / AMPP TM0187

Evaluating elastomers in sour gas environments

A test method for exposing elastomers to sour gas environments and assessing the effect.

Used in sour-service evaluation of seals.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

NACE / AMPP TM0296

Evaluating elastomers in sour liquid environments

A test method for exposing elastomers to sour liquid environments.

Used in sour-service evaluation of seals.

Oil and gas qualification

Confirm the current edition and any amendments before quoting it.

NACE / AMPP MR0175 / ISO 15156

Materials for H2S-containing environments

A set of requirements for metallic materials in sour service. It does not qualify elastomers.

Often quoted by mistake for seals. Elastomers need ISO 23936-2 or an equivalent route.

Oil and gas qualification

Metallic materials only. Confirm the current edition and any amendments before quoting it.

NSF/ANSI 61

Drinking water system components, health effects

Tests whether substances leaching from a component into drinking water stay within health-based limits. It is a health-effects standard and does not rate performance.

Common US market requirement. The approval belongs to the specific formulation, manufacturer and facility.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

NSF/ANSI 372

Drinking water system components, lead content

Sets a method for determining lead content of drinking water system components.

Used with NSF/ANSI 61 in the US.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

NSF/ANSI 51

Food equipment materials

Covers materials used in food equipment, including requirements for rubber.

Applies to food processing equipment seals.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

NSF/ANSI 50

Swimming pool and spa equipment

Covers equipment for pools and spas.

Reference only.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

WRAS BS 6920

Non-metallic products in contact with drinking water

UK route for products in contact with water for human consumption.

UK market requirement for water-contact seals.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

UBA Elastomer guideline (KTW)

Elastomers in contact with drinking water (Germany)

German assessment guideline for elastomers in drinking water applications.

Requested by German buyers.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

DVGW W 270

Microbial growth on materials in drinking water

Tests whether a material promotes microbial growth in drinking water.

Often asked for alongside the elastomer guideline.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

AS/NZS 4020

Products in contact with drinking water

Australian and New Zealand test standard.

Relevant for exports there.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

FDA 21 CFR 177.2600

Rubber articles for repeated food contact

US federal food-contact regulation for rubber articles intended for repeated use. It lists permitted ingredients and extraction limits.

Common requirement for food and beverage equipment seals.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

EU Regulation 1935/2004

Materials in contact with food

EU framework regulation for materials and articles in contact with food. There is no EU-wide rubber-specific measure, so national rules and recommendations apply.

Needed for EU food-contact claims.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

BfR Recommendation XXI

Commodities based on natural and synthetic rubber

German recommendation for rubber in food contact, widely used as a reference in Europe.

Frequently requested by European buyers.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

EN 549

Rubber materials for gas appliances and equipment

European requirements for rubber seals and diaphragms for gas appliances and equipment.

Gas appliance seals.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

EN 682

Seals for pipes and fittings carrying gas and hydrocarbon fluids

European material requirements for seals in gas and hydrocarbon service.

Gas distribution seals.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

EN 681-1

Pipe-joint seals, water and drainage

European material requirements for pipe-joint seals in water and drainage applications.

Water and drainage seals.

Water, food and gas contact

Confirm the current edition and any amendments before quoting it.

ISO 9001

Quality management systems

General requirements for a quality management system.

Large buyers often require a certified system from approved suppliers.

Quality and regulatory

You hold no certification until an accredited body issues one.

ISO/IEC 17025

Competence of testing laboratories

Requirements for the competence of testing and calibration laboratories.

Use accredited labs for test reports that must hold up.

Quality and regulatory

Confirm the current edition and any amendments before quoting it.

EU REACH (1907/2006)

Registration, evaluation and authorisation of chemicals

EU chemicals regulation. Importers and manufacturers of substances and mixtures have obligations on registration, communication and restrictions.

Compounds sold into the EU can bring REACH duties for the chemicals in them.

Quality and regulatory

Confirm the current edition and any amendments before quoting it.

US TSCA

Toxic Substances Control Act

US chemicals law. Imported substances must be on the TSCA inventory or exempt.

Check inventory status before importing raw materials or compounds.

Quality and regulatory

Confirm the current edition and any amendments before quoting it.

EU PFAS restriction proposal (ongoing)

Restriction proposal covering per- and polyfluoroalkyl substances

A proposal under REACH to restrict a very wide group of fluorine-containing substances. Fluoropolymers and fluoroelastomers may be affected. Its scope and timing have changed, so follow the current status.

A strategic risk for FKM and FEPM; essential-use arguments matter.

Quality and regulatory

Status changes. Check ECHA and your trade body for the current position.

ISO 2230

Rubber products, guidelines for storage

Gives guidance on storing vulcanised rubber products: temperature, humidity, light, ozone, contact with other materials, and shelf-life thinking.

Cited by buyers who ask how long a seal may sit in a warehouse before use.

Temperature and ageing

Guidance, not a pass or fail test. Read the current edition.

Standards are published by their respective organisations (ASTM International, ISO, SAE, API, NORSOK, AMPP and others). Pascalor is independent of all of them. Listing a standard does not mean that a Pascalor product has been tested to it.