Oil-free, self-lubricating, mechanical carbon-graphite materials feature a low coefficient of friction and good wear properties in a high speed environment, making them an excellent choice for aircraft gearbox face seals. All Metcar materials are impermeable and thus able to support the dynamic film used.
They minimize common problems associated with seal face wear, frictional heat, blistering, and coking, especially at temperatures higher than 400°F.
Grades include:
- M-45 has excellent thermal conductivity, which gives it the capability to maintain lower seal face temperature
- M-346 is antimony-impregnated and frequently finds use in gearbox seals to avoid seal face blistering or to improve seals' resistance to coking
- M-133 is carbon-impregnated and offers the same capabilities as M-346
