Quenching Oils are a series of heat treatment fluids, each with a different viscosity, for various metal quenching objectives. The series includes Quenching Oil 39I, 39L, 39LI, 42L, 43L and 45HL. Of these, 39I and 39L are formulated using Group II base oil and are general purpose quenching oils. 39L is of low viscosity. 39LI has higher flash point and low volatility. 42L is a compounded type quenching oil with low viscosity. 43L and 45HL are additive type quenching oils with low viscosity range. Standards: Quenching Oils are blended using solvent refined base oil with specially selected additives and conform to performance specifications as per BIS:2664-1980 (reaffirmed 2014) compounded type. Advantages: Quenching Oils enable accelerated quenching through proper and controlled cooling and impart uniform hardness to quenched components. These oils possess excellent thermal and oxidation stability. They also have high flash and fire properties. Minimal losses due to evaporation, hence reduced top-ups and low volatility hence reduce consumption, making them cost effective. They also reduce sludge formation and minimize oil thickening making the oils effective for longer periods.