F34.02 - Tribology

SIGNIFICANCE AND USE
5.1 Relevance of the Spiral Orbit Tribometer (SOT)—The SOT was designed to evaluate the relative degradation rates of liquid lubricants in a contact environment similar to that in an angular contact bearing operating in the boundary lubrication regime. It functions as a screening device to quickly select the lubricants, evaluate the ability of various components of a lubricant (base oil, thickener, or additive) to lubricate a contact in rolling, pivoting, and sliding conditions simultaneously, and study their chemical decomposition if necessary. The SOT provides a means to study the tribological behavior of oils and greases during operation, while they undergo changes as a function of typical parameters encountered in the lubrication field (temperature, environment, materials used, load applied, and speed). Test conclusion is defined to be when a friction coefficient limit (typically an increase of 0.1 above the steady state value) is surpassed. Normalized lubricant lifetime is then defined as the number of orbits completed divided by the initial amount of lubricant used (in μg). The SOT was initially developed to evaluate lubricants for space applications, but is also relevant for conventional environments. Some results in vacuum are presented (Fig. 1). At this time, no data for tests in ambient conditions have been published (see Fig. 2). The user of this test method should determine to their own satisfaction whether results of this test procedure correlate with field performance or other bench test procedures.
FIG. 1 Relative lifetimes of three typical space lubricants at 23°C in vacuum on 52100 steel  
Pepper, S.V., Kingsbury, E.P., “Spiral Orbit Tribometry – Part II: Evaluation of Three Liquid Lubricants in Vacuum”,  Tribo. Trans., V 46, 1, pp 65-69, 2003
FIG. 2 Comparison between full scale bearing tests** and SOT data at 23°C on 440C steel.  
Bazinet, D.G., Espinosa, M.A., Loewenthal, S.H., Gschwender, L., Jones, W.R., Jr., Predmore, R.E., “Life of Scan...
SCOPE
1.1 This test method covers the quantitative determination of the friction coefficient and the lifetime of oils and greases, when tested on a standard specimen under specified conditions of preparation, speed, Hertzian stress, materials, temperature, and atmosphere, by means of the Spiral Orbit Tribometer (SOT). This test method is intended primarily as an evaluation of the lifetimes of fluid lubricants under vacuum and ambient conditions.  
1.2 This standard may involve hazardous materials, operations, and equipment. 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.  
1.3 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.

SIGNIFICANCE AND USE
4.1 The purpose of this guide is to report on the testing of, to discuss and compare the properties of, and to provide guidelines for the choice of lubricating greases for precision rolling element bearings (PREB). The PREB are, for the purposes of this guide, meant to include bearings of Annular Bearing Engineer's Committee (ABEC) 5 quality and above. This guide limits its scope to lubricating greases used in PREB.  
4.2 The number of lubricating greases used in PREB increased dramatically from the early 1940s to the mid 1990s. In the beginning of this period, petroleum products were the only widely available base stocks. Later, synthetic base oils became available. They included synthetic hydrocarbons, esters, silicones, multiply alkylated cyclopentanes (MAC) and fluorinated materials, including perfluorinated ethers and the fluorosilicones. This broad spectrum of lubricant choices has led to the use of a large number of different lubricants in PREB applications. The U.S. Department of Defense, as a user of many PREB, has seen a significant increase in the logistics effort required to support the procurement and distribution of these items. In addition, as time has passed, some of the greases used in certain PREB are no longer available or require improved performances due to advanced bearing technology/requirements. This implies that replacement lubricating greases must be found, especially in this era of extending the lifetime of DoD assets, with the consequent and unprojected demand for sources of replacement parts.  
4.3 One of the primary goals of this study was to take a broad spectrum of the lubricating greases used in PREB and do a comprehensive series of tests on them in order that their properties could be compared and, if necessary, potential replacement greases be identified. This study is also meant to be a design guide for choosing lubricating greases for future PREB applications. This guide represents a collective effort of many members of this co...
SCOPE
1.1 This guide is a tool to aid in the choice of lubricating grease for precision rolling element bearing applications. The recommendations in this guide are not intended for general purpose bearing applications There are two areas where this guide should have the greatest impact: (1) when lubricating grease is being chosen for a new bearing application and (2) when grease for a bearing has to be replaced because the original grease specified for the bearing can no longer be obtained. The Report (see Section 5) contains a series of tests on a wide variety of greases commonly used in bearing applications to allow comparisons of those properties of the grease that the committee thought to be most important when making a choice of lubricating grease. Each test was performed by the same laboratory. This guide contains a listing of the properties of greases by base oil type, that is, ester, perfluoropolyether (PFPE), polyalphaolefin (PAO), and so forth. This organization is necessary since the operational requirements in a particular bearing application may limit the choice of grease to a particular base oil type and thickener due to its temperature stability, viscosity index or temperature-vapor pressure characteristics, etc. The guide provides data to assist the user in selecting replacement greases for those greases tested that are no longer available. The guide also includes a glossary of terms used in describing/discussing the lubrication of precision and instrument bearings.  
1.2 The lubricating greases presented in this guide are commonly used in precision rolling element bearings (PREB). These greases were selected for the testing based on the grease survey obtained from DoD, OEM and grease manufactures and evaluated according to the test protocol that was designed by Subcommittee F34 on Tribology. This test protocol covers the essential requirements identified for precision bearing greases. The performance requirem...

SIGNIFICANCE AND USE
4.1 The purpose of this guide is to report on the testing of, to discuss and compare the properties of, and to provide guidelines for the choice of lubricants for precision rolling element bearings (PREB). The PREB are, for the purposes of this guide, meant to include bearings of ABEC 5 quality and above. This guide limits its scope to oils used in PREB and is to be followed by a similar document to encompass greases used in PREB.  
4.2 The number of lubricants, both oils and greases, used in PREB increased dramatically from the early 1940s to the mid 1990s. In the beginning of this period, petroleum products were the only widely available base stocks. Later, synthetic lubricants became available including synthetic hydrocarbons, esters, silicones, and fluorinated materials, including perfluorinated ethers and the fluorosilicones. This broad spectrum of lubricant choices has led to the use of a large number of different lubricants in PREB applications. The U.S. Department of Defense, as a user of many PREB, has seen a significant increase in the logistics effort required to support the procurement and distribution of these items. In addition, as time has passed some of the lubricants used in certain PREB are no longer available. The SRG Series, LSO-26, and Teresso V-78 are examples of such lubricants. This implies that replacement lubricants must be found as, in this era of extending the lifetime of DoD assets, stockpiles of replacement parts become depleted.  
4.3 One of the primary goals of this study was to take a broad spectrum of the lubricants used in PREB and do a comprehensive series of tests on them in order that their properties could be compared and, if necessary, potential replacement lubricants identified. This study is also meant to be a design guide for choosing lubricants for PREB applications. This guide represents a collective effort of many members of this community who span the spectrum from bearing manufacturers, original equipment manufacture...
SCOPE
1.1 This guide is a tool to aid in the choice of an oil for precision rolling element bearing applications. There are two areas where this guide should have the greatest impact: (1) when a lubricant is being chosen for a new bearing application and (2) when a lubricant for a bearing has to be replaced because the original lubricant specified for the bearing can no longer be obtained. The Report (Section 5) contains a series of tests performed by the same laboratory on a wide variety of oils commonly used in bearing applications to allow comparisons of those properties of the oil that the committee thought to be most important when making a choice of lubricant. This guide contains a listing of the properties of oils by chemical type, that is, ester, silicone, and so forth. This organization is necessary since the operational requirements in a particular bearing application may limit the choice of lubricant to a particular chemical type due to its temperature stability, viscosity index or temperature-vapor pressure characteristics, and so forth. The Report includes the results of tests on the oils included in this study. The Report recommends replacement lubricants for those oils tested that are no longer available. The Report also includes a glossary of terms used in describing/discussing the lubrication of precision and instrument bearings. The Report presents a discussion of elastohydrodynamic lubrication as applied to rolling element bearings.  
1.2 Although other compendia of lubricant properties have been published, for example, the Barden Product Standard, Lubricants2 and the NASA Lubricant Handbook for the Space Industry3, none have centered their attention on lubricants commonly used in precision rolling element bearings (PREB). The PREB put a host of unique requirements upon a lubricant. The lubricant must operate at both high and low temperatures. The lubricant must provide lubrication for months, if not years,...

SIGNIFICANCE AND USE
5.1 Relevance of the Spiral Orbit Tribometer (SOT)—The SOT was designed to evaluate the relative degradation rates of liquid lubricants in a contact environment similar to that in an angular contact bearing operating in the boundary lubrication regime. It functions as a screening device to quickly select the lubricants, evaluate the ability of various components of a lubricant (base oil, thickener, or additive) to lubricate a contact in rolling, pivoting, and sliding conditions simultaneously, and study their chemical decomposition if necessary. The SOT provides a means to study the tribological behavior of oils and greases during operation, while they undergo changes as a function of typical parameters encountered in the lubrication field (temperature, environment, materials used, load applied, and speed). Test conclusion is defined to be when a friction coefficient limit (typically an increase of 0.1 above the steady state value) is surpassed. Normalized lubricant lifetime is then defined as the number of orbits completed divided by the initial amount of lubricant used (in μg). The SOT was initially developed to evaluate lubricants for space applications, but is also relevant for conventional environments. Some results in vacuum are presented (Fig. 1). At this time, no data for tests in ambient conditions have been published (see Fig. 2). The user of this test method should determine to their own satisfaction whether results of this test procedure correlate with field performance or other bench test procedures.  
Bazinet, D.G., Espinosa, M.A., Loewenthal, S.H., Gschwender, L., Jones, W.R., Jr., Predmore, R.E., “Life of Scanner Bearings with Four Space Liquid Lubricants”, Proc. 37th  Aerospace Mech. Symp., Johnson Space Center, May 19-21, 2004
SCOPE
1.1 This test method covers the quantitative determination of the friction coefficient and the lifetime of oils and greases, when tested on a standard specimen under specified conditions of preparation, speed, Hertzian stress, materials, temperature, and atmosphere, by means of the Spiral Orbit Tribometer (SOT). This test method is intended primarily as an evaluation of the lifetimes of fluid lubricants under vacuum and ambient conditions.  
1.2 This standard may involve hazardous materials, operations, and equipment. 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 to determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 The purpose of this guide is to report on the testing of, to discuss and compare the properties of, and to provide guidelines for the choice of lubricating greases for precision rolling element bearings (PREB). The PREB are, for the purposes of this guide, meant to include bearings of Annular Bearing Engineer's Committee (ABEC) 5 quality and above. This guide limits its scope to lubricating greases used in PREB.  
4.2 The number of lubricating greases used in PREB increased dramatically from the early 1940s to the mid 1990s. In the beginning of this period, petroleum products were the only widely available base stocks. Later, synthetic base oils became available. They included synthetic hydrocarbons, esters, silicones, multiply alkylated cyclopentanes (MAC) and fluorinated materials, including perfluorinated ethers and the fluorosilicones. This broad spectrum of lubricant choices has led to the use of a large number of different lubricants in PREB applications. The U.S. Department of Defense, as a user of many PREB, has seen a significant increase in the logistics effort required to support the procurement and distribution of these items. In addition, as time has passed, some of the greases used in certain PREB are no longer available or require improved performances due to advanced bearing technology/requirements. This implies that replacement lubricating greases must be found, especially in this era of extending the lifetime of DoD assets, with the consequent and unprojected demand for sources of replacement parts.  
4.3 One of the primary goals of this study was to take a broad spectrum of the lubricating greases used in PREB and do a comprehensive series of tests on them in order that their properties could be compared and, if necessary, potential replacement greases be identified. This study is also meant to be a design guide for choosing lubricating greases for future PREB applications. This guide represents a collective effort of many members of this co...
SCOPE
1.1 This guide is a tool to aid in the choice of lubricating grease for precision rolling element bearing applications. The recommendations in this guide are not intended for general purpose bearing applications There are two areas where this guide should have the greatest impact: (1) when lubricating grease is being chosen for a new bearing application and (2) when grease for a bearing has to be replaced because the original grease specified for the bearing can no longer be obtained. The Report (see Section 5) contains a series of tests on a wide variety of greases commonly used in bearing applications to allow comparisons of those properties of the grease that the committee thought to be most important when making a choice of lubricating grease. Each test was performed by the same laboratory. This guide contains a listing of the properties of greases by base oil type, that is, ester, perfluoropolyether (PFPE), polyalphaolefin (PAO), and so forth. This organization is necessary since the operational requirements in a particular bearing application may limit the choice of grease to a particular base oil type and thickener due to its temperature stability, viscosity index or temperature-vapor pressure characteristics, etc. The guide provides data to assist the user in selecting replacement greases for those greases tested that are no longer available. The guide also includes a glossary of terms used in describing/discussing the lubrication of precision and instrument bearings.  
1.2 The lubricating greases presented in this guide are commonly used in precision rolling element bearings (PREB). These greases were selected for the testing based on the grease survey obtained from DoD, OEM and grease manufactures and evaluated according to the test protocol that was designed by Subcommittee F34 on Tribology. This test protocol covers the essential requirements identified for precision bearing greases. The performance requirem...

SIGNIFICANCE AND USE
The purpose of this guide is to report on the testing of, to discuss and compare the properties of, and to provide guidelines for the choice of lubricants for precision rolling element bearings (PREB). The PREB are, for the purposes of this guide, meant to include bearings of ABEC 5 quality and above. This guide limits its scope to oils used in PREB and is to be followed by a similar document to encompass greases used in PREB.
The number of lubricants, both oils and greases, used in PREB increased dramatically from the early 1940s to the mid 1990s. In the beginning of this period, petroleum products were the only widely available base stocks. Later, synthetic lubricants became available including synthetic hydrocarbons, esters, silicones, and fluorinated materials, including perfluorinated ethers and the fluorosilicones. This broad spectrum of lubricant choices has led to the use of a large number of different lubricants in PREB applications. The U.S. Department of Defense, as a user of many PREB, has seen a significant increase in the logistics effort required to support the procurement and distribution of these items. In addition, as time has passed some of the lubricants used in certain PREB are no longer available. The SRG Series, LSO-26, and Teresso V-78 are examples of such lubricants. This implies that replacement lubricants must be found as, in this era of extending the lifetime of DoD assets, stockpiles of replacement parts become depleted.
One of the primary goals of this study was to take a broad spectrum of the lubricants used in PREB and do a comprehensive series of tests on them in order that their properties could be compared and, if necessary, potential replacement lubricants identified. This study is also meant to be a design guide for choosing lubricants for PREB applications. This guide represents a collective effort of many members of this community who span the spectrum from bearing manufacturers, original equipment manufactures (OEMs), lubr...
SCOPE
1.1 This guide is a tool to aid in the choice of an oil for precision rolling element bearing applications. There are two areas where this guide should have the greatest impact: (1) when a lubricant is being chosen for a new bearing application and (2) when a lubricant for a bearing has to be replaced because the original lubricant specified for the bearing can no longer be obtained. The Report (Section 5) contains a series of tests performed by the same laboratory on a wide variety of oils commonly used in bearing applications to allow comparisons of those properties of the oil that the committee thought to be most important when making a choice of lubricant. This guide contains a listing of the properties of oils by chemical type, that is, ester, silicone, and so forth. This organization is necessary since the operational requirements in a particular bearing application may limit the choice of lubricant to a particular chemical type due to its temperature stability, viscosity index or temperature-vapor pressure characteristics, and so forth. The Report includes the results of tests on the oils included in this study. The Report recommends replacement lubricants for those oils tested that are no longer available. The Report also includes a glossary of terms used in describing/discussing the lubrication of precision and instrument bearings. The Report presents a discussion of elastohydrodynamic lubrication as applied to rolling element bearings.
1.2 Although other compendia of lubricant properties have been published, for example, the Barden Product Standard, Lubricants and the NASA Lubricant Handbook for the Space Industry , none have centered their attention on lubricants commonly used in precision rolling element bearings (PREB). The PREB put a host of unique requirements upon a lubricant. The lubricant must operate at both high and low temperatures. The lubricant must provide lubrication for months, if not years, w...

SCOPE
1.1 This test method covers the quantitative determination of the friction coefficient and the lifetime of oils and greases, when tested on a standard specimen under specified conditions of preparation, speed, Hertzian stress, materials, temperature, and atmosphere, by means of the Spiral Orbit Tribometer (SOT). This test method is intended primarily as an evaluation of the lifetimes of fluid lubricants under vacuum and ambient conditions.
This standard may involve hazardous materials, operations, and equipment. 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 to determine the applicability of regulatory limitations prior to use.

SCOPE
1.1 This guide is a tool to aid in the choice of lubricating grease for precision rolling element bearing applications. The recommendations in this guide are not intended for general purpose bearing applications There are two areas where this guide should have the greatest impact: (1) when lubricating grease is being chosen for a new bearing application and (2) when grease for a bearing has to be replaced because the original grease specified for the bearing can no longer be obtained. The Report (see Section ) contains a series of tests on a wide variety of greases commonly used in bearing applications to allow comparisons of those properties of the grease that the committee thought to be most important when making a choice of lubricating grease. Each test was performed by the same laboratory. This guide contains a listing of the properties of greases by base oil type, that is, ester, perfluoropolyether (PFPE), polyalphaolefin (PAO), and so forth. This organization is necessary since the operational requirements in a particular bearing application may limit the choice of grease to a particular base oil type and thickener due to its temperature stability, viscosity index or temperature-vapor pressure characteristics, etc. The guide provides data to assist the user in selecting replacement greases for those greases tested that are no longer available. The guide also includes a glossary of terms used in describing/discussing the lubrication of precision and instrument bearings.
1.2 The lubricating greases presented in this guide are commonly used in precision rolling element bearings (PREB). These greases were selected for the testing based on the grease survey obtained from DoD, OEM and grease manufactures and evaluated according to the test protocol that was designed by Subcommittee F34 on Tribology. This test protocol covers the essential requirements identified for precision bearing greases. The performance requirements of these greases are very unique. They are dictated by the performance expectations of precision bearings including high speed, low noise, extended life, and no contamination of surrounding components by the bearings lubricant system. To increase the reliability of test data, all tests were performed by a DoD laboratory and three independent testing laboratories. There were no grease manufacturers data imported except for base oil viscosity. Most of tests were performed by U.S. Army Tank-Automotive Research, Development and Engineering Center (TARDEC) and three independent laboratories, and the results were monitored by the Naval Research Laboratory (NRL). This continuity of testing should form a solid basis for comparing the properties of the multitude of lubricating greases tested by avoiding some of the variability introduced when greases are tested by different laboratories using different or even the "same" procedures. Additional test data will be considered for inclusion, provided the defined protocol is followed and the tests are performed by independent laboratories.
1.3 This study was a part of DoD Aging Aircraft Replacement Program and supported by Defense Logistic Agent (DLA) and Defense Supply Center Richmond (DSCR).
1.4 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 limitations prior to use.

SIGNIFICANCE AND USE
The purpose of this guide is to report on the testing of, to discuss and compare the properties of, and to provide guidelines for the choice of lubricants for precision rolling element bearings (PREB). The PREB are, for the purposes of this guide, meant to include bearings of ABEC 5 quality and above. This guide limits its scope to oils used in PREB and is to be followed by a similar document to encompass greases used in PREB.
The number of lubricants, both oils and greases, used in PREB increased dramatically from the early 1940s to the mid 1990s. In the beginning of this period, petroleum products were the only widely available base stocks. Later, synthetic lubricants became available including synthetic hydrocarbons, esters, silicones, and fluorinated materials, including perfluorinated ethers and the fluorosilicones. This broad spectrum of lubricant choices has led to the use of a large number of different lubricants in PREB applications. The U.S. Department of Defense, as a user of many PREB, has seen a significant increase in the logistics effort required to support the procurement and distribution of these items. In addition, as time has passed some of the lubricants used in certain PREB are no longer available. The SRG Series, LSO-26, and Teresso V-78 are examples of such lubricants. This implies that replacement lubricants must be found as, in this era of extending the lifetime of DoD assets, stockpiles of replacement parts become depleted.
One of the primary goals of this study was to take a broad spectrum of the lubricants used in PREB and do a comprehensive series of tests on them in order that their properties could be compared and, if necessary, potential replacement lubricants identified. This study is also meant to be a design guide for choosing lubricants for PREB applications. This guide represents a collective effort of many members of this community who span the spectrum from bearing manufacturers, original equipment manufactures (OEMs), lubr...
SCOPE
1.1 This guide is a tool to aid in the choice of an oil for precision rolling element bearing applications. There are two areas where this guide should have the greatest impact: (1) when a lubricant is being chosen for a new bearing application and (2) when a lubricant for a bearing has to be replaced because the original lubricant specified for the bearing can no longer be obtained. The Report (Section 5) contains a series of tests performed by the same laboratory on a wide variety of oils commonly used in bearing applications to allow comparisons of those properties of the oil that the committee thought to be most important when making a choice of lubricant. This guide contains a listing of the properties of oils by chemical type, that is, ester, silicone, and so forth. This organization is necessary since the operational requirements in a particular bearing application may limit the choice of lubricant to a particular chemical type due to its temperature stability, viscosity index or temperature-vapor pressure characteristics, and so forth. The Report includes the results of tests on the oils included in this study. The Report recommends replacement lubricants for those oils tested that are no longer available. The Report also includes a glossary of terms used in describing/discussing the lubrication of precision and instrument bearings. The Report presents a discussion of elastohydrodynamic lubrication as applied to rolling element bearings.
1.2 Although other compendia of lubricant properties have been published, for example, the Barden Product Standard, Lubricants and the NASA Lubricant Handbook for the Space Industry, none have centered their attention on lubricants commonly used in precision rolling element bearings (PREB). The PREB put a host of unique requirements upon a lubricant. The lubricant must operate at both high and low temperatures. The lubricant must provide lubrication for months, if not years, wit...

SIGNIFICANCE AND USE
This test method is a screening test to differentiate among the expected life of greases in ball bearings running at high temperatures. If torque is a factor in selection of a grease, the test method provides for measurements at both low (1 r/min) and high (12 000 r/min) speeds.
SCOPE
1.1 This test method describes a procedure for the determination of grease life and torque in small bearings. Although this test method is not the equivalent of a long-time field-service test, it is intended to predict the relative grease life at high temperature in a reasonable period of testing time. In addition, this test method measures the running torque at both low (1 r/min) and high (12 000 r/min) speeds.
1.2 Except for torque, which is measured in gcm, the values stated in inch-pound units are to be regarded as the standard in this test method. The SI values given in parenthesis are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This test method describes a procedure for the determination of grease life and torque in small bearings. Although this test method is not the equivalent of a long-time ASTM 100HARBOR WEST CONSHOHOCKEN, PAfield-service test, it is intended to predict the relative grease life at high temperature in a reasonable period of testing time. In addition, this test method measures the running torque at both low (1 r/min) and high (12 000 r/min) speeds.
Formerly under the jurisdiction of Committee F34 on Rolling Element Bearings, this test method was withdrawn in July 2009 due to the unavailability of test apparatus. There is no replacement of this test method.