Vespel SP-1 - Unfilled. Maximum strength & elongation; lowest modulus & thermal conductivity: optimum electrical properties.

Vespel SP-21 - 15% graphite (by weight). Enhances inherent wear resistance, improves long term thermal stability.

Vespel SP-22 - 40% graphite (by weight). Gives low coefficient of thermal expansion. Maximum creep resistance.

Vespel SP-211 - 15% graphite and 10% TEFLON® fluorocarbon resin (by weight). Lowest static friction.

Vespel SP-3 - 15% MoS2(by weight). Best wear performance in dry environments.