Sealing material comprises from 45% to 90% by weight exfoliated graphite, from 5% to 20% by weight thermosetting resin and from 5% to 50% by weight fibrous filler which is heat resistant at 250.degree. C. The fibrous filler has fibres at least 90% of which have a fibre length of less than 200 .mu.m, and an aspect ratio of less than 10:1.

O material do sealing compreende 45% a 90% pelo peso exfoliated a grafita, 5% a 20% pela resina thermosetting do peso e 5% a 50% pelo enchimento fibrous do peso que é resistente ao calor em 250.degree. C. O enchimento fibrous tem as fibras ao menos 90% de que têm um comprimento da fibra menos do mu.m de 200, e uma relação de aspecto menos de de 10:1.