Customer note: ASTM D2000 suffix designations are test specific and not interchangeable. Materials must be qualified to the exact suffix shown on the drawing unless formal engineering approval is obtained.
How ASTM D2000 Identifies the Elastomer Type
In an ASTM D2000 material designation, the first letter after “M” defines the elastomer family.
“M” simply means the material is classified under ASTM D2000.
The next letter is what tells you the rubber type.
ASTM D2000 Elastomer Type Codes
| ASTM Code | Elastomer Type | Common Names | Typical Use |
|---|---|---|---|
| BA | Nitrile Rubber | NBR, Buna-N | Oils, fuels, hydraulics |
| BG | Nitrile, High ACN | HNBR (sometimes), specialty NBR | Higher heat and oil resistance |
| BK | Polychloroprene | Neoprene | Refrigerants, moderate oils |
| CA | EPDM | EPDM | Water, steam, brake fluid, ozone |
| CH | Epichlorohydrin | ECO | Fuels, low temp flexibility |
| CS | Silicone | VMQ | Extreme temperature, low strength |
| FC | Fluorocarbon | FKM, Viton® | High temp, aggressive chemicals |
| FE | Fluorosilicone | FVMQ | Fuel resistance plus low temp |
| FK | Fluoroelastomer (special) | FFKM variants (limited) | Extreme chemical resistance |
| GB | Polyurethane | AU, EU | Abrasion, wipers, scrapers |
| HC | Polyacrylate | ACM | Automotive transmission fluids |
| Z | Special purpose | Custom compounds | Defined by suffixes only |
Example Breakdown (Real World)
Example 1
ASTM D2000 M2BG710
- M = ASTM D2000 material
- BG = Nitrile rubber (high acrylonitrile content)
- 710 = 70 Shore A hardness with standard tensile and elongation
This tells you immediately: this is a Buna-N / NBR compound, even before suffixes are applied.
Example 2
ASTM D2000 M3CA710 A14 B13 C12
- CA = EPDM
- 710 = 70 Shore A
- A14 = Heat aging
- B13 = Compression set
- C12 = Ozone resistance
This is how ASTM D2000 defines EPDM 70 without ever saying the word “EPDM”.
Example 3
ASTM D2000 M2FC815
- FC = Fluorocarbon
- That means FKM (Viton®-type material)
- Suffixes then control heat, fluids, compression set, etc.
A Heat Aging Resistance
| Suffix | Test Condition |
|---|---|
| A1 | 70 hours at 70°C |
| A2 | 70 hours at 100°C |
| A3 | 70 hours at 125°C |
| A4 | 70 hours at 150°C |
| A5 | 70 hours at 175°C |
| A6 | 70 hours at 200°C |
| A7 | 168 hours at 70°C |
| A8 | 168 hours at 100°C |
| A9 | 168 hours at 125°C |
| A10 | 168 hours at 150°C |
| A11 | 168 hours at 175°C |
| A12 | 168 hours at 200°C |
| A13 | 70 hours at 250°C |
| A14 | 70 hours at 125°C (commonly used) |
| A25 | 70 hours at 125°C with tighter limits |
B Compression Set (ASTM D395 Method B)
Typical deflection is 25% unless otherwise specified by the standard.
| Suffix | Time | Temperature | Maximum Set | Notes |
|---|---|---|---|---|
| B1 | 22 hours | 70°C | 50% | |
| B2 | 22 hours | 100°C | 50% | |
| B3 | 22 hours | 125°C | 50% | |
| B4 | 22 hours | 150°C | 50% | |
| B5 | 22 hours | 175°C | 50% | |
| B6 | 22 hours | 200°C | 50% | |
| B11 | 22 hours | 70°C | 35% | |
| B12 | 22 hours | 100°C | 35% | |
| B13 | 22 hours | 70°C | 25% | Tighter set requirement |
| B14 | 22 hours | 100°C | 25% | Tighter set requirement |
| B15 | 22 hours | 125°C | 25% | Tighter set requirement |
| B31 | 70 hours | 70°C | 50% | |
| B32 | 70 hours | 100°C | 50% | |
| B33 | 70 hours | 125°C | 50% | |
| B34 | 70 hours | 150°C | 50% | |
| B35 | 22 hours | 100°C | 50% | Commonly seen on datasheets |
| B36 | 22 hours | 125°C | 50% | Commonly seen on datasheets |
C Ozone Resistance (ASTM D1171)
Acceptance is typically no visible cracking per the applicable ASTM D2000 table.
| Suffix | Ozone | Temperature | Strain | Time | Acceptance |
|---|---|---|---|---|---|
| C11 | 25 pphm | 40°C | 20% | 72 hours | No visible cracking |
| C12 | 50 pphm | 40°C | 20% | 72 hours | No visible cracking |
| C13 | 100 pphm | 40°C | 20% | 72 hours | No visible cracking |
| C21 | 25 pphm | 40°C | 20% | 168 hours | No visible cracking |
| C22 | 50 pphm | 40°C | 20% | 168 hours | No visible cracking |
| C23 | 100 pphm | 40°C | 20% | 168 hours | No visible cracking |
| C31 | 25 pphm | 40°C | 20% | 500 hours | No visible cracking |
| C32 | 50 pphm | 40°C | 20% | 500 hours | No visible cracking |
| C33 | 100 pphm | 40°C | 20% | 500 hours | No visible cracking |
EA Fuel A Resistance
| Suffix | Condition |
|---|---|
| EA11 | 70 hours at 23°C |
| EA12 | 70 hours at 50°C |
| EA13 | 70 hours at 70°C |
| EA14 | 70 hours at 100°C |
| EA15 | 70 hours at 125°C |
EO Oil Resistance
| Suffix | Oil | Temperature | Time |
|---|---|---|---|
| EO11 | IRM 901 | 70°C | 70 hours |
| EO12 | IRM 903 | 100°C | 70 hours |
| EO13 | IRM 903 | 125°C | 70 hours |
F Low Temperature Brittleness (ASTM D2137)
| Suffix | Temperature |
|---|---|
| F1 | -40°C |
| F2 | -55°C |
| F3 | -60°C |
| F17 | -40°C, non-brittle (commonly used) |
G Tear Resistance (ASTM D624)
| Suffix | Minimum Tear Strength |
|---|---|
| G11 | 10 kN/m |
| G21 | 25 kN/m |
| G31 | 35 kN/m |
ASTM D2000 Suffix Requirements
The rest of an ASTM D2000 material designation consists of suffix requirements. Suffix requirements are used when the basic requirements in ASTM D2000 for a specific type and class of material are not sufficient to achieve the desired properties in the finished product.
Suffix requirements consist of alpha characters (the property being tested) and numeric characters (the test conditions and acceptance limits). The suffixes must match the drawing or specification unless engineering approval is obtained.
| Suffix | Required Test / Property |
|---|---|
| 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 |
Understanding ASTM D2000 Numeric Suffixes
In ASTM D2000, the numeric portion of a suffix defines the exact test conditions, including temperature, time, strain, fluid type, and allowable limits. The numbers are not performance rankings and are not interchangeable.
| Example | Test Type | What the Number Specifies |
|---|---|---|
| A14 | Heat Aging Resistance | Material is heat aged for 70 hours at 125°C. Changes in hardness, tensile strength, and elongation must remain within ASTM D2000 limits. |
| B13 | Compression Set | Compression set tested per ASTM D395 Method B, 22 hours at 70°C, with a maximum allowable compression set of 25%. |
| B35 | Compression Set | Compression set tested per ASTM D395 Method B, 22 hours at 100°C, with a maximum allowable compression set of 50%. |
| C12 | Ozone Resistance | Ozone exposure per ASTM D1171, 50 pphm ozone, 40°C, 20% strain, for 72 hours. Acceptance requires no visible cracking. |
| C32 | Ozone Resistance | Ozone exposure per ASTM D1171, 50 pphm ozone, 40°C, 20% strain, for 500 hours. Acceptance requires no visible cracking. |
| EA14 | Water / Fuel A Resistance | Volume change after immersion in Fuel A or water, 70 hours at 100°C, within ASTM D2000 allowable limits. |
| F17 | Low Temperature Resistance | Brittleness testing per ASTM D2137. Material must remain non-brittle at low temperature as defined by the standard. |
| G21 | Tear Resistance | Tear strength tested per ASTM D624, with a minimum required tear strength of 25 kN/m. |