This paper is a reasonably complete presentation of the formulation, the physical and chemical properties, and the pump loop behavior of a deep-dewaxed mineral oil, MLO 60–294. Properties given include: (a) viscosity and bulk modulus as functions of both temperature and pressure, (b) specific heat, density, thermal expansion, vapor pressure, and thermal conductivity as functions of temperature, and (c) pour, cloud, flash, and fire points. The behavior of this fluid in one pump loop to 700 F, and in a second loop to 600 F, is discussed. Excellent fluid performance was obtained in these pump loops at 400, 500, 550, and 600 F; however, the fluid degraded rapidly at 700 F.Presented as an American Society of Lubrication Engineers paper at the Lubrication Conference held in Rochester, New York, October 15–17, 1963.