ASTM International

(American Society for Testing and Materials)

ASTM D2000 is a classification system that covers the properties of vulcanized rubber materials (natural rubber, reclaimed rubber, synthetic rubbers alone or in combination) that are intended for, but not limited to, use in rubber products in automotive applications.

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.

Here’s a complete ASTM D 2000 Call-Out.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

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. So, when you’re reading about temperatures, think Centigrade instead of Fahrenheit. If the M is missing, then English units are used.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Grade

In our example, the 2 after the -3 is the grade of the rubber. Typically, grade numbers are only given 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 a rubber’s temperature resistance – and is so important in our sample ASTM D 2000 “sentence” that Type is like a noun! Look for the type (B) after the grade (2).

 ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

With types, 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

So what are these specified temperatures? That’s what the table below explains.

Table 1 – Types

ASTM D 2000 assigns a letter to each test temperature. Again, our example uses Type B.

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. In case you’re wondering, that’s the maximum temperature stability of the test oil (IRM No. 903) used in ASTM D 2000.

In the language of rubber, class is so important that it’s like a verb. By putting a noun (type) and verb (class) together, we form a basic sentence in ASTM D 2000. As with most English sentences, too, our verb (G) follows the noun (B).

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Table 2 – Classes

ASTM D 2000 then assigns lettered classes to each maximum allowable volume swell by percentage (%). Again, our example uses Class G.

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 our example of 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

As we’ve learned, the language of rubber contains the equivalent of nouns, verbs, adjectives, adverbs, and other parts of speech. There are suffixes, too – literally. These combinations of letters and numbers can be quite long, depending on your requirements. As you can see, our example is half suffix!

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Table 3 – Suffix Letters

ASTM D 2000 assigns a letter to each suffix elements.

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)

Table 4 – 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.