A rubber like material that when compressed and released will return to 90% of its original shape in less than five seconds.

If it takes more than five seconds, or if the part returns to less than 90% of its original shape we say the material is a plastic.

Viton® is an elastomer. Teflon® is a plastic.

This is the reason O-rings are made 10% oversize. If you measure a 1/8 inch cross section O-ring it does not measure 0.125 inches, it measures 0.139 inches instead, even though the tolerance is plus or minus 0.003 inches

® E.I. Dupont


  • Selection of the O-ring, SA005
  • Temperature limits for elastomers SA005-1


  • On February 15, 2018