Krytox™ GPL-407 grease is made using a non-melting thickener, instead of the normal Krytox™ PTFE. This change from PTFE to silica boosts the temperature capability of the grease to an upper limit determined by the evaporation/breakdown temperature of the oil. Krytox™ GPL-407 is made from Krytox™ GPL-107 oil, which, with proper ventilation, can withstand up to 399 °C (750 °F) and higher temperatures for brief periods. With replenishment/re-lubrication, it can last longer. While Krytox™ GPL-407 is not meant to replace the Krytox™ GPL-200 series at temperatures below 288–316 °C (550–600 °F), it does extend the range for using fluorinated greases to beyond the 316 °C (600 °F) limit of PTFE and Teflon™ thickened greases. Krytox™ GPL 407 has higher oil separation than PTFE thickened greases and, therefore, might not last as long under equivalent conditions.Information provided by Chemours Krytox |