H-538

MIL-PRF-87257

HYDRAUNYCOIL FH 42

SYNTHETIC HYDRAULIC FLUID

HYDRAUNYCOIL FH 42 is synthetic hydrocarbon base hydraulic fluid for use in the - 54oC to + 135oC temperature range in aircraft and missile hydraulic systems. It is also used in automatic pilots, shock absorbers and brakes. It is microfiltered.


Main characteristics

Properties Units Typical values Test methods
Appearance at 20oC — red clear liquid —
Density at 20oC kg/dm3 0.832 ASTM D 4052
Kinematic viscosity mm2/s   ASTM D 445
at 100oC   2.33  
  40oC   7.81  
  -40oC   530  
  -54oC   2400  
Flash point oC 176 ASTM D 92
Pour point oC <-66 ASTM D 97
Acid number (pH = 11) mg KOH/g 0.01 ASTM D 664