ASTM D 2000 Specifications for Rubber Buyers and Suppliers

Topics Covered

Introduction
Call Outs
Standard
Year Last Revised
Units of Measure
Grade
Type
Class
Durometer Hardness and Tensile Strength
Suffixes
Suffix Numbers
About Elasto Proxy

Introduction

ASTM D 2000 is a published specification that provides buyers and suppliers with a standard way to describe rubber. Designed for automotive applications, this classification system is also used by other industries because ASTM D 2000 is clear, concise, and highly descriptive.

This article shows buyers how to read ASTM D 2000 specifications so that they can communicate with suppliers in a common language. By learning more about the ASTM language of rubber, buyers can more readily identify the materials that they need.

Call Outs

ASTM D 2000 uses letters and numbers to describe or “call out” the properties of vulcanized rubber. Type and Class are the most important call outs to consider.

In the language of rubber, Types and Classes are like nouns and verbs – the building blocks of sentences. There are also other callouts that help with descriptions and represent other parts of “speech”.

The following is a complete call-out or “sentence” in ASTM D 2000. This will serve as an example throughout the article.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

The language of rubber may look complex, but the key is to crack the code one step at a time. Here are the components.

  • Standards
  • Year Last Revised
  • Units of Measure
  • Grade
  • Durometer Hardness and Tensile Strength
  • Suffixes

Standard

The first few letters and numbers (ASTM D 2000) simply indicate the standard.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Year Last Revised

The -3 after the 2000 indicates the year (2003) in which the standard was last revised.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Units of Measure

The M after the -3 indicates that all units of measure are metric. If the M is missing, then English units are used.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Grade

The 2 after the -3 is the grade of the rubber. Typically, grade numbers are given only when the basic requirement (Grade 1) doesn’t sufficiently describe the material’s properties.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Type

Type describes the rubber’s temperature resistance, an important material property. Below, look for the type (B) after the grade (2).

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Note also that a rubber material must meet the following requirements after 70 hours of heat aging at a specified temperature.

  • Change in tensile strength: ±30%
  • Change in hardness: -50% max.
  • Change in hardness ±15 points

ASTM D 2000 assigns a letter (such as B) to each test temperature. The following tables explain these specified temperatures.

Table 1. Types

Type Test Temp (°C)
A 70
B 100
C 125
D 150
E 175
F 200
G 225
H 250
J 275
K 300

Class

Class describes a rubber’s resistance to swelling in oil after 70 hours at the temperatures listed in Table 1, but only up to 150° C. This is the maximum temperature stability of the test oil (IRM No. 903) used in ASTM D 2000.

In the language of rubber, class is like a verb. By using a noun (type) and a verb (class) together, a basic sentence in ASTM D 2000 can be formed.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

ASTM D 2000 then assigns lettered classes (such as G) to each maximum allowable volume swell by percentage (%).

Table 2. Classes

Type Max. Swell (%)
A No requirement
B 140
C 120
D 100
E 80
F 60
G 40
H 30
J 20
K 10

Durometer Hardness and Tensile Strength

ASTM D 2000 defines durometer hardness and tensile strength with a three-digit number.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

In the above example (714), the 7 denotes a material with a durometer hardness of 70 ± 5 A. The 14 indicates that the tensile strength must be at least 14 MPa, or 2032 psi.

Suffixes

The language of rubber contains the equivalent of parts of speech as well as suffixes. These combinations of letters and numbers canbe lengthy, depending on the material.

In the example below, almost half of the letters and numbers belong to the suffix.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

As this table shows, ASTM D 2000 assigns a letter to each suffix element.

Table 3. Suffix Letters

Suffix Required Test
A Heat Resistance
B Compression Set
C Ozone or Weather Resistance
D Compression-Deflection Resistance
EA Water Resistance
EF Fuel Resistance
EO Oil and Lubricant Resistance
F Low Temperature Resistance
G Tear Resistance
H Flex Resistance
J Abrasion Resistance
K Adhesion
M Flammability Resistance
N Impact Resistance
P Staining Resistance
R Resilience
Z Other (User-Defined)

With regard to color, assume black except for FC, FE, FK, and GE. For applications that require a different color material, buyers should note that a color change may also change the rubber’s physical properties.

Suffix Numbers

In addition to letters, suffixes contain numbers.

  • The first number specifies the duration of the test and the test method.
  • The second number indicates the testing temperature.

Understanding all of the suffix numbers requires purchasing the ASTM D 2000 specification. In that document, refer to Tables 4 and 5 for details.

About Elasto Proxy

Elasto Proxy designs and custom fabricates specialty seals, thermal and acoustic insulation, vibration dampening products and materials, EMI shielding, and other high-quality rubber and plastic parts. By listening to all of your requirements and analyzing all of your needs, Elasto Proxy’s solutions providers can recommend solutions that are right for your application.

This information has been sourced, reviewed and adapted from materials provided by Elasto Proxy.

For more information on this source, please visit Elasto Proxy.

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