QC Lubricants
7360 Milnor St. Philadelphia, PA 19136
(215) 333-4187 Direct Line

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We actively supply a comprehensive line of MIL-SPEC  and commercial lubricants.

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This hydraulic fluid is blended with highly refined mineral based oils and modern additive technology to provide protection against rust, wear, demulsibility, and to afford greatly improved viscosity - temperature characteristics as well as enhanced oxidation corrosion resistance.

This specification covers the requirements for one type of synthetic
hydrocarbon base hydraulic fluid.
The type of hydraulic fluid is as follows:
Type I - Undyed and Identified by Military Symbol FRH and NATO Code No. H-544.

Intended use
The hydraulic fluid covered by this specification is intended for use in recoil mechanisms and hydraulic systems of military ground vehicles and equipment.
If used in other mechanisms or systems, a study should be made to determine its applicability for such usage, with particular attention given to operation at high and low temperatures and the topic of elastomer compatibility. The hydraulic fluid is rust inhibited and may be used as a preservative medium for hydraulic systems and components.
The hydraulic fluid has a wide range of operating temperatures and is thermally stable, corrosion inhibited, and fire resistant. The combination of all of these quantities is not found in commercial hydraulic fluids. This fluid is adopted for military use by NATO countries. (NOTE: TYPE II of the previous revision C
is no longer available.)


This specification covers the requirements for one type of synthetic hydrocarbon base hydraulic fluid

Hydraulic Fluid, Rust Inhibited, Fire Resistant, Synthetic Hydrocarbon Base

Intended for use in recoil mechanisms and hydraulic systems of military ground vehicles and equipment. If used in other mechanisms or systems, a study should be made to determine its applicability for such usage  

Royco 770 Ty 1

Fluid handling
Owing to the difficulty of preventing contamination after the opening of a container, it is recommended that the hydraulic fluid be purchased in 1-quart and 1-gallon containers by all users. If the fluid is dispensed from larger containers, strict procedures must be employed to exclude and remove moisture, solid particles or other contaminants from the fluid.

Recommended corrosion inhibitor
It has been found that 1.75 0.25% barium dinony1naphthalene sulfonate provides the required degree of rust protection. The diluent of the rust inhibitor should be the synthetic hydrocarbon base stock.

Handling and safety precautions
CAUTION: Personnel handling the product shall wear appropriate impervious clothing to prevent repeated or prolonged skin contact.
The local environmental officials will relate health and safety implications as well as to prescribe precise application of protective clothing. If skin or clothing becomes moistened with the product, personnel should promptly wash with soap or mild detergent and water. Respirators are not required unless there is a potential for inhalation exposure to misting. Personnel should wear protective clothing when using the product and when cleaning up spills.

Background (safety)
The product may contain 0.5% tricresyl phosphate, of which not more than 0.01% may be present as the ortho isomer. If this ortho isomer of tricresyl phosphate is absorbed through the skin or taken internally, it may cause paralysis. The corrosion
inhibitor contains barium. The accumulated waste liquids will have the exterior of the outer pack marked as containing barium and tricresyl phosphate to assist disposal facilities to manage the product according to regulations promulgated by the US Environmental Protection Agency under Public Law 94-580, Resource Conservation and Recovery Act of 1976.

Storage conditions
Prior to use of product in the intended equipment, the product
may be stored under conditions of covered or uncovered storage on geographic areas ranging in temperature from 57C to 71C (-71F to 160F).

Interchangeability and compatibility
MIL-PRF-46170 fluids are not interchangeable with any other fluids.
MIL-PRF-46170 fluids are not to be regarded as compatible with any other fluids except those conforming to MIL-PRF-5606, MIL-PRF-6083, MIL-PRF-83282, and
MIL-PRF-87257. Dilution with MIL-PRF-5606 or MIL-PRF-6083 severely lowers the flash point.

MIL-PRF-46170 Qualification
The hydraulic fluid furnished under this specification shall be
products that are authorized by the qualifying activity for listing on the applicable qualified  products list before contract award. Any change in the formulation of a  qualified product will require re-qualification.

Hydraulic fluid
The hydraulic fluid shall consist of a synthetic hydrocarbon base
stock (alpha-olefin polymer). Additives shall not include resins, gums, fatty oils, oxidized hydrocarbons, chlorine or silica.

Kinematic viscosity
The kinematic viscosity of the hydraulic fluid shall be as
specified in table below, TABLE 1:
TABLE I. Kinematic viscosity
Temperature,C (F) Kinematic viscosity, mm2 /s 1/
40 (104)19.5, maximum
100 (212)3.4, minimum
-40 (-40)2600, maximum

1/  mm 2/s = Square millimeters per second.

Trace sediment
The hydraulic fluid shall have maximum trace sediment of 0.005 milliliter (mL)

Water content
The hydraulic fluid shall have maximum water weight of  0.05 percent.

Acid or base number
The hydraulic fluid shall have maximum acid or base number of 0.20 milligrams (mg) of potassium hydroxide per gram of hydraulic fluid (mg KOH/gram (g).

Bulk modulus
The isothermal secant bulk modulus of the hydraulic fluid shall be 1.379 x 106
kilopascals (kPa) minimum, at 40C (104F) at pressures between 0 and 68 950 kPa.

Water sensitivity
The light transmittance of a water-treated sample of hydraulic fluid shall be a minimum of 90%.

Corrosion protection (humidity cabinet)
The hydraulic fluid shall protect specially prepared steel test panels to the extent that no more than three corrosion dots, none of which exceed 1 mm in diameter, occur on any of the panels.

Corrosiveness (bimetallic couple)
The hydraulic fluid shall not promote galvanic
corrosion, in excess of three spots, on any one of the steel test disks covered with a brass clip.

Solid particle contamination
Particle size
The number of solid contamination particles per 100 mL of the hydraulic fluid shall not be greater than the numbers specified in table II.

TABLE II. Particle size
26-50 250
over 10010

Gravimetric method
The solid particle contamination of the hydraulic fluid shall not be greater than 0.5 mg/100 mL.

Foaming characteristics

Foaming tendency
The foam volume of the hydraulic fluid shall not exceed 65 mL (following any of the 5-minute blowing periods of the foaming characteristics test.

Foam stability
There shall be no foam remaining in the hydraulic fluid, in excess of a ring of bubbles around the edge of the test container, following any of the 10-minute settling periods of the foaming characteristics test.

Wear (Lubricity)
During the wear test, the hydraulic fluid shall lubricate the steel balls such that the average scar diameters on the steel balls shall not exceed 0.30 mm if the test load is 147 Newtons (N), or 0.65 mm if the test load is 392 N.

High temperature - high pressure spray ignition
The hydraulic fluid, when sprayed and ignited, shall be self-extinguishing.

Linear flame propagation
The linear flame propagation rate of the hydraulic fluid shall not exceed 0.30 centimeters per second (cm/s).

Relative Density (specific gravity)
The relative density of transparent low-viscosity hydraulic fluid samples submitted for conformance testing shall be reproducible to no more than +/-0.0012 and repeatable to no more than +/-0.0005 (no units) between the temperature range of -2C to +24.5C (29F to 76F), and no more than +/-0.008 from the relative density of the sample approved in qualification testing. Relative density shall be expressed at 60F/60F or at some temperature between 29F to 76F. Temperatures may be the same or different, but in both cases shall be explicitly stated, for example, 65F/65F, or 50F/65F. Report the final value as relative density, with no dimensions, at the two reference temperatures, to the nearest 0.0001.

Interface requirements
Corrosiveness and oxidation stability (metal protection)

Weight change of test specimens
The hydraulic fluid shall not produce corrosion or oxidation effects such that the weight change of the metal specimens, except for copper specimen, exceeds a gain or loss of 0.2 milligrams per square centimeter (mg/cm2). For the copper specimen, the weight gain or loss shall not exceed 0.6 mg/cm2

Appearance of test specimens
The hydraulic fluid shall not cause etching, pitting, or visible corrosion on the surface of the metal specimens, except for the copper specimen. Any corrosion produced on the surface of the copper specimen shall not be greater than No. 2 of ASTM D130 Copper Corrosion Standards.

Viscosity change
The viscosity of the oxidized hydraulic fluid at 40C (104F)
shall not change more than 10% from the initial viscosity measured at 40C (104F).
Acid or base number change
The acid or base number of the oxidized hydraulic fluid shall not increase more than 0.30 mg KOH/g over the initial acid or base number.
Insoluble material
The oxidized hydraulic fluid shall exhibit no insoluble materials or gum when examined.

Swelling of synthetic rubber
Following immersion in the hydraulic fluid at a temperature of 70C (158F) for 168 hours, standard synthetic rubber NBR-L, in accordance with (IAW) SAE AMS 3217/2B, shall exhibit a percent volume change within the range of 15 to

The hydraulic fluid shall be compatible, in all concentrations, with each of the fluids approved under this specification, as well as hydraulic fluids conforming to:
MIL-PRF-5606, MIL-PRF-6083, MIL-PRF-83282, and MIL-PRF-87257

Fire point
The minimum fire point of the hydraulic fluid shall be 246C (475F)

Pour point
The maximum pour point of the hydraulic fluid shall be -54C (-65F)
Evaporation loss
The maximum mass percent evaporation loss of the hydraulic
fluid shall be 5%.

Autoignition temperature
The minimum autoignition temperature of the hydraulic
fluid shall be 343C (649F).

Low temperature stability
The hydraulic fluid shall show no evidence of gelling, crystallization, solidification or separation of insoluble material when subjected to a temperature of -40 6C (-40 11F) for 72 hours.
For acquisition purposes, the packaging requirements shall be specified in the contract or order. When actual packaging of materiel is to be performed by DoD or in-house contractor personnel, these personnel need to contact the responsible packaging activity to ascertain packaging requirements. Packaging requirements are maintained by the Inventory Control Point's packaging activities within the Military Services or Defense Agency, or within the military service's system commands. Packaging data retrieval is available from the managing Military Department's or Defense Agency's automated packaging files, CD-ROM products, or by contacting the responsible packaging activity.

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