ISO 6743-4 classification

ISO – L – HH – Mineral lubricants without corrosion inhibitors ISO – L – HL – Lubricants HH with oxidation-reduction and anticorrosive additives
ISO – L – HM – HL lubricants with wear reducing additives
ISO – L – HR – HL lubricants with a high viscosity index
ISO – L – HV – HM lubricants with a high viscosity index
ISO – L – HG – HM lubricants with shock resistant features
ISO – L – HS – Synthetic liquids

ISO 6743-4 classification of fireproof hydraulic liquids:
ISO – L – HFAE – Emulsion, oil-in-water
ISO – L – HFAS – Chemical combinations in water
ISO – L – HFB – Emulsion, water-in-oil
ISO – L – HFC – Water / glycol
ISO – L – HFDR – Phosphorus esters – without water
ISO – L – HFDS – Chlorinated hydrocarbons – without water
ISO – L – HFDT – HFDR / HFDS mixtures
ISO – L – HFDU – Anhydrous liquids, more resistant than HFDR, HFDS or HFDT

ISO 6743-4 classification of biodegradable hydraulic liquids:
ISO – L – HETG – Triglycerides (vegetable oils)
ISO – L – HEES – Synthetic esters
ISO – L – HEPG – Polyglycols