British Standard O-Rings are very similar to Standard O-Rings in the fact that they are both standardized imperically. The British Standard however, incorporates some extended sizes in the 1/4" nominal cross section group for an even broader application range. British Standard O-Rings serve a variety of industries including aerospace, paint, food, and chemical transport. Buna is also known as: Nitrile, NBR, N, Buna-N.

Nitrile, chemically, is a copolymer of butadiene and acrylonitrile. Acrylonitrile content is varied in commercial products from 18% to 48%. As the nitrile content increases, resistance to petroleum base oils and hydrocarbon fuels increases, but low temperature flexibility decreases.

Due to its excellent resistance to petroleum products, and its ability to be compounded for service over a temperature range of -65 to +275°F(-54 to +135°C), nitrile is the most widely used elastomer in the seal industry today.

Inherently nitrile does not possess good resistance to ozone, sunlight or weather, but this can be substantially improved through compounding.For more information, please see: Comparison Properties Chart, PTFE Encapsulated O-rings, Material Shelf Life, and O-ring Groove Design Chart.
Unit of Measure

Type

N/A BS Standard O-Ring

Material

N/A Buna

Cross Section Width

N/A 0.275 in6.99 mm

Durometer

N/A 90

Inside Diameter

N/A 6.125 in155.58 mm

CSW Tolerance

N/A 0.006 in0.15 mm

BS Number

N/A -872

Warning

N/A Prop 65 Warning: This product may contain chemicals known to the State of California to cause cancer, and birth defects or other reproductive harm.

O-Ring Industries

N/A O-rings are used in the military defense and agriculture industries.