| Standard Gasket Compound# | BG7A1 | |
| Common Names/Aliases | Buna-N (Nitrile Rubber) | |
| Grade | Commercial | |
| Color | Black | |
| Chemical Group (ASTM D-2000 Code) | NBR (BG) | |
| Application | General purpose rubber with excellent elastomeric properties plus resistance to petroleum based lubricants and hydrocarbon fuels. Most common and cost effective rubber o-ring compound. | |
| Competing Compounds | N674, 7507, B46-70, 4200-70, HI4327, 366Y | |
| Standard Specifications (related technical specs detailed below) | ASTM D-2000-99 M2BG714-B14-EA14-EF11-EF21-EO14-EO34-F17 | |
| Physical Properties | ||
| Item (Unit) | Specification | Actual |
| Hardness - Durometer | 70 +/- 5 Shore A | 70 Shore A |
| Tensile Strength | 2031 psi (14 Mpa) max | 2476 psi (17 Mpa) |
| Elongation% | 250% min | 385% |
| Temperature Range | -40 F/+250 F (-40 C /+121 C) | |
| Specific Gravity | n/a | 1.24 |
| Actual Test Data (ASTM D2000 Suffix Reference) | ||
| Heat Age, 70 hrs @ 212o F (100o C) | ||
| Hardness-Durometer Change | +/- 15 Shore A max | +1 Shore A |
| Tensile Strength Change | +/- 30% max | +4% |
| Elongation% Change | -50% max | -16% |
| (B14) Compression Set, 22 hrs @ 212o F (100o C) | ||
| Original Deflection | 25% max | 16.7% |
| Compression Deflection% | n/a | n/a |
| (EA14) Water Resistance, 70 hrs @ 212o F (100o C) | ||
| Hardness-Durometer Change | +/-10 Shore A max | +2 |
| Volume Change | +/- 15% max | +6.2% |
| (EF11) Fuel A Resistance, 70 hrs @ 73o F (23o C) | ||
| Hardness-Durometer Change | +/- 10 Shore A | +1 Shore A |
| Tensile Strength Change | -25% max | -6.3% |
| Elongation% Change | -25% max | -2.3% |
| Volume Change | -5/+10% | +1.5% |
| (EF21) Fuel B Resistance, 70 hrs @ 73o F (23o C) | ||
| Hardness-Durometer Change | -30/0 Shore A | -7 Shore A |
| Tensile Strength Change | -60% max | -37.8% |
| Elongation% Change | -60% max | -26.2% |
| Volume Change | +40% max | +21.1% |
| (EO14) ASTM #1 Oil, 70 hrs @ 212o F (100o C) | ||
| Hardness-Durometer Change | -5/+10 Shore A | +2 Shore A |
| Tensile Strength Change | -25% max | +3.2% |
| Elongation% Change | -45% max | -12.8% |
| Volume Change | -10/+5% | -3.7% |
| (EO34) ASTM #3 Oil, 70 hrs @ 212o F (100o C) | ||
| Hardness-Durometer Change | -10/+5 Shore A | -5 Shore A |
| Tensile Strength Change | -45% | -10% |
| Elongation% Change | -45% | -11.4% |
| Volume Change | +25% | +7.8% |
| (F17) Low Temperature Brittleness, 3 min @ -40o F (-40o C) | ||
| Per ASTM D2137, Method A | Non-Brittle | Non-Brittle |
| Per ASTM D2137, Method A | n/a | n/a |