Excellent resistance to oxidation and thermal changes allowing repeated quenchings owing to: - the use of solvent-refined base oils, - the presence of effective and durable antioxidant additives which give long bath life.  High flash point to ensure risk-free operation in the utilization temperature range.  Low volatility limits evaporation loss and the formation of vapours and fumes.  Effective, durable cooling powers guarantee mechanical properties achieved after quenching (hardness, depth of hardness).  Low fluidity at the temperature of use reduces loss by entrainment, resulting in product savings.  Good antifoam properties which are essential on account of the high swirling of oil in the hardening tanks.