Locks QA-HT33 is a low viscosity heat transfer oil formulated on highly refined high viscosity index paraffinic base oil. It is specially designed for closed heat transfer systems with bulk oil temperatures up to 320℃. Locks QARA HT32 can also be used as a general purpose quenching oil. Because of the effect of oxidation, the life of any mineral oil in an open system declines rapidly at temperature beyond 100℃. Therefore, attention must be paid to eliminate the direct contact of air when using mineral heat transfer oil.