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Technical Data Sheet
Skydrol® 500B-4 Fire Resistant Hydraulic Fluid

  • Aviation hydraulic fluid

Product Description

The Skydrol 500 series of fluids has the longest service history among phosphate ester products. The first version, Skydrol 500, was introduced in 1952. Steady improvements to the formulation led in 1977 to the current version, Skydrol™ 500B-4 which contains the same breakthrough anti erosion additive and acid scavenger found in Skydrol™ LD-4 . Skydrol 500B-4 is the most worker friendly of the aviation phosphate esters. This has given the product enormous popularity for use in work shops and indoor test stands..

Typical Properties

PropertyTest MethodTypical Value, Units
Acid Number (mg KOH/g) 0.10 Maximum
Appearance Clear, oily liquid
Autoignition TemperatureASTM D 2155460 °C (860 °F ) Minimum
Color Purple, essentially equivalent to intensity and hue standard
Elemental Content 
     Calcium 10 ppm, Maximum
     Chlorine 50 ppm, Maximum
     Potassium 30 ppm, Maximum
     Sodium 10 ppm, Maximum
     Sulfur 1185-1460 ppm
Fire Point 
     COC 191 °C (375 °F ) Minimum
Flash Point 
     COC 177 °C (350 °F ) Minimum
Moisture 0.20 % Maximum
Particle Contaminationa 
     15-25 micron size 5,700 Maximum
     25-50 micron size 1,012 Maximum
     50-100 micron size 180 Maximum
     5-15 micron size 32,000 Maximum
     Over 100 micron size 32 Maximum
Pour Point -62 °C (-80 °F ) Maximum
Specific Gravity 
     @ 25°C/25°C 1.050-1.062
     @ 38°C (100°F) 11.40-12.40 cSt
     @ -54°C (-65°F) 2900 cSt Maximum
     @ 99°C (210°F) 3.68-4.00 cSt

aNAS 1638 particle counts per AS4059F

Properties reported here are typical of average lots. Eastman makes no representation that the material in any particular shipment will conform exactly to the values given.

Eastman and its marketing affiliates shall not be responsible for the use of this information, or of any product, method, or apparatus mentioned, and you must make your own determination of its suitability and completeness for your own use, for the protection of the environment, and for the health and safety of your employees and purchasers of your products. No warranty is made of the merchantability of fitness of any product, and nothing herein waives any of the Seller's conditions of sale.

8/28/2018 3:59:33 PM