mercury oils

Hydraulic Lubricants


Hydra FRE Rvn no : 1

Fire resistant hydraulic fluid

Hydra FRE is a long life hydraulic fluid with high flash point synthetic ester, provided with good lubricating properties and long equipment life. Meets the requirements of ISO 6743/4 standard as fire resistant HFDU and ISO 15380 HEES class. Hydromax FR-E can be applied as hydraulic fluid whenever operating close to heat source. Hydromax is highly biodegradable so small leakages will not cause contamination.


Hydra FRE is suitable for hydraulic applications in:

  • Hot rolling
  • Continuous casting
  • Ingots conveyors
  • Metal casting
  • Stamping, forging and sintering
  • Thermic treatments ovens
  • Welding machines

No special care is required when handling this product. Hydromax FR-E is compatible with most of the common rubbers of the mineral oil operated circuits including NBR, unless in good condition. Natural rubbers and polyurethane are not advised.

Use conditions

  • When using Hydra FRE in a circuit which had been operating with a mineral hydraulic oil, it is sufficient to proceed as follows:
  • Unload the circuit and clean the tank, making sure that the inner wall is not painted
  •  Take off and clean the filters
  •  Load the tank with Hydra FRE to the minimum level
  •  Run the circuit 1 or 2 hours under low pressure monitoring all movements
  •  Unload, and then set the filters, load again the tank with new Hydra FRE, and operate in normal conditions

Typical performance data

  Test method FR-E 46 FR-E 68
Appearance MD 0 Clear liquid Clear liquid
Viscosity @ 40 °C, cSt ASTM D-445 46 68
Viscosity @ 100 °C, cSt ASTM D-445 9.13 12.3
Viscosity Index ASTM D-2270 >180 >180
Density @ 20 °C, g/ml ASTM D-1298 0.925 0.935
Flash point, ºC ASTM D-92 >300 >300
Pour point, ºC ASTM D-97 <-30 <-30
N.N., mgKOH/g ASTM D-974 <1 <1
Demulsivity, ml/min ASTM D-1401 Max 40/37/3 (30’) Max 40/37/3 (30’)


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