ASTM D6158-05 - 1.6.2005
 
1. Scope

1.1 This specification covers mineral oils used in hydraulic systems, where the performance requirements demand fluids with one of the following characteristics:

1.1.1 A refined base oil (Class HH),

1.1.2 A refined mineral base oil with rust and oxidation inhibitors (Class HL), and

1.1.3 A refined mineral base oil with rust and oxidation inhibitors plus antiwear characteristics (Class HM).

1.2 This specification defines the requirements of mineral oil-based hydraulic fluids that are compatible with most existing machinery components when there is adequate maintenance.

1.3 This specification defines only new lubricating oils before they are installed in the hydraulic system.

1.4 This specification defines specific types of hydraulic oils. It does not include all hydraulic oils. Some oils that are not included may be satisfactory for certain hydraulic applications. Certain equipment or conditions of use may permit or require a wider or narrower range of characteristics than those described herein.

The following safety hazard caveat pertains to the test methods referenced in this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitation prior to use.

 
2. Referenced Documents

D5950-25

Standard Test Method for Pour Point of Petroleum Products (Automatic Tilt Method)

D5182-26

Standard Test Method for Evaluating the Scuffing Load Capacity of Oils (FZG A/8.3/90 Method)

D6973-14(2024)

Standard Test Method for Indicating Wear Characteristics of Petroleum Hydraulic Fluids in a High Pressure Constant Volume Vane Pump

D7043-24

Standard Test Method for Indicating Wear Characteristics of Non-Petroleum and Petroleum Hydraulic Fluids in a Constant Volume Vane Pump

D7752-26

Standard Practice for Evaluating Compatibility of Mixtures of Hydraulic Fluids

ISO 13357-1

Petroleum ProductsDetermination of the Filterability of Lubricating OilsPart 1: Procedure for Oils in the Presence of Water

ISO 13357-2

Petroleum ProductsDetermination of the Filterability of Lubricating oilsPart 2: Procedure for Dry Oils

DIN 51350-6

CEC L-45-A-99

Viscosity Shear Stability of Transmission Lubricants (KRL Taper Roller Bearing Rig)

D2422-24

Standard Classification of Industrial Fluid Lubricants by Viscosity System

D92-24

Standard Test Method for Flash and Fire Points by Cleveland Open Cup Tester

D97-17b(2022)

Standard Test Method for Pour Point of Petroleum Products (Includes all amendments and changes 11/29/2022).

D130-26

Standard Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip Test

D445-26

Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)

D471-16a(2021)

Standard Test Method for Rubber Property—Effect of Liquids (Includes all amendments and changes 6/25/2021).

D664-24

Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration

D665-25

Standard Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water

D892-25

Standard Test Method for Foaming Characteristics of Lubricating Oils

D943-25

Standard Test Method for Oxidation Characteristics of Inhibited Mineral Oils

D974-22

Standard Test Method for Acid and Base Number by Color-Indicator Titration

D1298-24

Standard Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method

D1401-21

Standard Test Method for Water Separability of Petroleum Oils and Synthetic Fluids

D2070-26

Standard Test Method for Thermal Stability of Hydraulic Oils

D2270-24

Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 ?C and 100 ?C

D2619-21

Standard Test Method for Hydrolytic Stability of Hydraulic Fluids (Beverage Bottle Method)

D2983-23

Standard Test Method for Low-Temperature Viscosity of Automatic Transmission Fluids, Hydraulic Fluids, and Lubricants using a Rotational Viscometer

D3427-26

Standard Test Method for Air Release Properties of Hydrocarbon Based Oils

D4052-22

Standard Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter

D4310-22a

Standard Test Method for Determination of Sludging and Corrosion Tendencies of Inhibited Mineral Oils (Includes all amendments and changes 11/10/2022).

D6080-18a(2025)

Standard Practice for Defining the Viscosity Characteristics of Hydraulic Fluids (Includes all amendments and changes 10/28/2025).