ASTM D2070-24

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2070 − 23 D2070 − 24
Standard Test Method for
Thermal Stability of Hydraulic Oils
This standard is issued under the fixed designation D2070; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method is designed primarily to evaluate the thermal stability of hydrocarbon based hydraulic oils although
oxidation may occur during the test.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
2.2 Copper Development Association Standard
UNS C11000 Electrolytic Tough Pitch Copper
2.3 American Iron and Steel Institute Standard (AISI)
W-1 Carbon Tool Steel
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
4. Summary of Test Method
4.1 A beaker containing test oil, copper and steel rods is placed in an aluminum block in an electric gravity convection oven for
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.N0 on Hydraulic Fluids.
Current edition approved July 1, 2023March 1, 2024. Published August 2023March 2024. Originally approved in 1991. Last previous edition approved in 20162023 as
ɛ1
D2070 – 16D2070 – 23. . DOI: 10.1520/D2070-23.10.1520/D2070-24.
This procedure was adopted from the Fives Cincinnati Thermal Stability Test Procedure “A”, Fives Cincinnati Manual 10-SP-89050.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from Copper Development Assoc., Inc., 260 Madison Ave., New York, NY 10016, http://www.copper.org.
Available from American Iron and Steel Institute (AISI), 25 Massachusetts Ave., NW, Suite 800, Washington, DC 20001, http://www.steel.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2070 − 24
168 h at a test temperature of 135 °C. At the completion of the test, the copper and steel rods are rated visually for discoloration
and the oil is analyzed for the quantity of sludge.
5. Significance and Use
5.1 Thermal stability characterizes physical and chemical property changes which may adversely affect an oil’s lubricating
performance. This test method evaluates the thermal stability of a hydraulic oil in the presence of copper and steel at 135 °C. No
correlation of the test to field service has been made.
6. Apparatus
6.1 An aluminum block with equally spaced holes is used. An example is described in Fig. A1.1 and Fig. A1.2 of Annex A1.
6.2 Electric gravity convection oven capable of maintaining the aluminum block at a test temperature of 135 °C 6 1 °C.
6.2.1 Calibrated thermocouple and temperature indicator centered in aluminum block.
6.3 250 mL Griffin beakers of borosilicate glass.
6.4 Copper test specimens are to be UNS C11000, 99.9 % pure electrolytic tough pitch copper, 6.35 mm in diameter by 7.6 cm
6,7
in length (0.25 in. by 3.0 in.).
6,7
6.5 Steel test specimens are to be AISI W-1 1 % carbon steel, 6.35 mm in diameter 7.6 cm in length (0.25 in. by 3.0 in.).
6.6 Silicon carbide abrasive 000 320320 grit CAMI-grade with cloth backing or its equivalent, metalworking aluminum oxide
abrasive cloth coated backing.
6.7 Crocus cloth.
8,7
6.8 41 Whatman filter paper,paper. 47 mm diameter.
9,7
6.9 Millipore filter, 8 μm Type SC, 47 mm diameter.SC.
6.10 Millipore glass filter holder, 47 mm, Cat #XX10.04700 or equivalent.equivalent to size of filter paper in 6.9.
10,7
6.11 Fives Cincinnati Lubricant Heat Test Standards Color Chart.
7. Reagents
7.1 Reagent Grade Heptane—(Warning—Flammable. Health hazard.)
7.2 Reagent Grade Acetone—(Warning—Flammable. Health hazard.)
8. Preparation of ApparatusCatalyst Rods
8.1 Handle the rods at all times using forceps or clean cotton gloves.
The sole source of supply of the apparatus known to the committee at this time is Metaspec LLC, 790 W. Mayfield Blvd., San Antonio, TX 78211,
metaspec@earthlink.net.Services LLC, San Antonio, TX, www.metaspec.com, sales@metaspec.com.
If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend.
The sole source of supply of the apparatus known to the committee at this time is Whatman Ltd., part of GE Healthcare, http://www.whatman.com.
The sole source of supply of the apparatus known to the committee at this time is EMD Millipore Corp., 290 Concord Rd., Billerica, MA 01821;
http://www.EMDmillipore.com.
The sole source of supply of the apparatus known to the committee at this time is Fives Cincinnati, 2200 Litton Ln., Hebron, KY 41048; http://www.fivesmsi.com.
D2070 − 24
8.2 Polish the steel and copper catalyst rods prior to use. Use only new rods for each test. Do not re-use rods.
8.3 CatalystPreliminary Preparation—Clean the steel and copper catalyst rods, whether new or previously used, prior to use.
Clean the Polish the rods with the 320 grit abrasive cloth while rotating the rods in a drill chuck at 1700 r ⁄min to 1800 r ⁄min. Clean
⁄min, unless using rods purchased from supplier pre-polished according to Test Method D2070. Polish the surface until it has a
bright copper or steel appearance. Discard rods when diameter is less than 6.2 mm.
8.4 Final Preparation—Prepare surface finally with a crocus cloth. cloth while rotating the rods in a drill chuck as indicated above.
Remove all grind marks. Finish the rods to a lightly polished surface finish.
8.5 WashRinse the rods individually with acetone and air dry on completion of the polishing operation.operation, then
immediately place into the test beaker followed by the test oil.
NOTE 1—If rods cannot be placed into the test beaker, then covered with the test oil immediately, completely polished rods may be stored for up to 24 h
in high-purity sulfur-free solvent such as isooctane. Once removed from the solvent, rinse the rods individually with acetone, air dry, then immediately
place into the test beaker foll
...