by melt dry or wet spinning a suitable liquid of the precursor material the polyacrylonitrile pan based fibers which have a normal nominal diameter of from 4 to 25 micrometers are collected as an assembly of a multiplicity of continuous filaments in tows the fibers are than stabilized for example by oxidation or any other conventional method of stabilization the stabilization fibers or tows which are typically made from chopped or stretch broken fiber staple are processed according to the invention and heat treated at elevated temperatures in an inert non oxidizing atmosphere for a period of time to produce a heat induced thermoset reaction typically nitrogen content for the fiber of between about 5 to 35 is maintained at a temperature range of from 150 u00b0 c to 525 u00b0 c and above the fibers are generally provided with a substantially permanent or irreversible heat set as a result of the higher temperature treatment of 525 u00b0 c and above a more permanent or irreversible crimp is imparted to the fibers or tows the resulting tows or fibers may be used per se the carbonaceous fibers derived from oxidized polyacrylonitrile based materials which provided by the invention are classified into three groups in a first group the carbonaceous fibers have a carbon content of greater than 65 but less than 85 are electrically nonconductive and do not possess any electrostatic dissipating characteristics i e they are not able to dissipate an electrostatic charge the term electrically nonconductive as utilized in the present invention relates to a resistance of greater than 4 u00d7 10 6 ohms cm 10 7 ohms in when measured on a 6k 6000 filaments tow of individual fibers having a.