Of the three ferrule types available graphite is the softest, making it less damaging to capillary columns when overtightened. Graphite seals easily and does not stick to glass columns. Recommended for use with capillary columns. Temperature limit is 450 °C.
Note: 0.25-0.32mm inner diameter. columns require 0.5mm inner diameter ferrules. 0.53mm inner diameter columns require 1.0mm inner diameter ferrules.