Hydrogenated castor oil (HCO) or castor wax is a hard, brittle wax that is insoluble. It is produced by adding hydrogen in the presence of a nickel catalyst.Hydrogenation of castor oil accounts for the largest single use of castor oil for a standard commodity.

The HCO is insoluble in water and most organic solvents, but it is soluble in hot solvents. It is water resistant while retaining lubricity, polarity and surface wetting properties. It is this insolubility that makes HCO valuable to the lubricants markets. It is perfect for metal drawing lubricants and multipurpose industrial greases.

Thus it is no surprise that HCO is mainly used for coatings and greases where resistance to moisture, oils and other petrochemical products is required. The early use of HCO in greases was to improve texture and oxidative stability of greases exposed to high sheer stress with little effect on structure or consistency. HCO made its debut in greases as a replacement for traditional soap thickeners, sodium, potassium and calcium.

Hydrogenated castor oil is also utilized in the manufacture of waxes, polishes, carbon paper, candles and crayons. In addition, it finds use in cosmetics, hair dressing, ointments, and in the preparation of hydroxyl-stearic acid and derivatives. Sometimes, HCO is used as a paint additive, pressure mould release agent in the manufacture of formed plastics and rubber goods.