500' Spool of Buna-N Nitrile O-Ring Cord

How to calculate O-ring cord length needed:

( ( OD + ID ) / 2 ) x Pi = length
Pi = 3.14159

Inside Diameter (ID) = Outside Diameter (OD) - twice the cross section (C/S)
ID = OD - (2 x C/S)

Make your own O-rings with O-ring Cord and O-ring Glue. How To Make an O-ring:

To calculate the correct length of cord required, (( OD + ID ) / 2 ) x Pi = Length. This will then give the correct length of cord required. Using the splicing aid and a very sharp knife. make a cut in the material at a right angle. All surfaces to be glued must be free of oil or grease. Avoid touching the surfaces. A thin layer of Cyanoacrylate Adhesive O-ring Glue should be spread over one side of the cut. A thin layer provides the best results. In order to join the two sides cleanly, use the V section on the splicing aid. Match both surfaces together and press firmly for 15 seconds. The glue must dry for 60 seconds before mounting the O-ring.

Nitrile, Buna-N O-Rings (NBR):

Nitrile, also known as Buna-N or NBR, is a copolymer of Butadiene and Acrylonitirle. It is the most commonly used elastomer for sealing products. It has a temperature range of -40F to +250F and is exceptionally resistant to petroleum base oils and hydrocarbon fuels. Nitrile materials also exhibit excellent tensile strength and abrasion resistance properties. The material performs well with most dilute acids, silicone oils and lubricants and in water applications. It is not recommended for use with ketones, aromatic hydrocarbons and phosphate ester hydraulic fluids. More than 50% of the Orings sold are Nitrile Orings, commonly used in hydraulic/pneumatic motors, cylinders, pumps and valves.

Buna-N / Nitrile Recommended uses:

• General purpose sealing.
• Petroleum oils and fluids.
• Hydraulic fluids
• Cold Water.
• Silicone greases and oils
• Di-ester base lubricants (MIL-L-7808).
• Ethylene glycol base fluids (Hydrolubes)

Nitrile is not recommended for:

• Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene)
• Nitro hydrocarbons (nitrobenzene, aniline)
• Phosphate ester hydraulic fluids (Skydrol, Fyrquel, Pydraul).
• Ketones (MEK, acetone)
• Strong Acids Ozone
• Automotive brake fluid.

Operating temperature: -40° to +250F°