Buna-N Gasket

Buna-N rubber is also known as Nitrile rubber. Nitrile elastomers are co-polymers of acrylonitrile and butadiene. The scientific name for Buna-N is acrylonitrile butadiene. The elastomer can be formulated with varying levels of acrylonitrile (ACN). The higher the content of ACN in the polymer formulation, the better the resistance to gasoline and aromatic oils. However, the lower ACN elastomers exhibit improved low temperature flexibility and tear resistance. Nitrile has a fairly impressive temperature range from -40F to250 F.

The ASTM D2000 classifications are BK, BF, and BG, the ASTM D1418 designation for this rubber is NBR. The history of this rubber is as versatile as the applications are for it. Buna-N rubber can be used as a general purpose sealing device such as O-Rings, seals, gaskets, diaphragms for oil field, automotive and aircraft industry. A popular use for nitrile is its use in the rubber glove industry. Rubber gloves are manufactured from nitrile where a non-latex glove is required.

Another elastomer belonging to Nitrile family is the hydrogenated acrylonitrile butadiene which is abbreviated HNBR per the ASTM D1418. This elastomer is similar but offers better heat, chemical and certain physical properties than regular NBR. The ASTM D2000 designation for HNBR is DH, DF, and CH.

NEDC works on applications including nitrile quite frequently and deals with the specifications associated, including MIL-G-1149, MIL-R-2765, MIL-R-6855 Class 1, and MIL-R-3065 SB (now superseded by the callout ASTM D2000 BG. In general the shelf life of Nitrile is 5-10 years.

Nitrile can be provided in many durometers from 30-90 Shore A. This rubber normally is provided in black because of the carbon black filler that is a reinforcing filler. NEDC can provide Nitrile rubber in sheet form, extruded cord stock, strips, die cut parts, water jet cut parts, and molded parts.

Due to NEDCs unique capability to fabricate sheets and convert them in the same facility, NEDC can mold custom thicknesses in any area between the normally calendared thicknesses of .020”, .031” .062”, .093” .125”, .250” .500”. NEDC can provide the elastomer in a variety of durometers which is an indication of the elastomers resistance to compression.