ASTM D2161-10(2016)

Standard Practice for Conversion of Kinematic Viscosity to Saybolt Universal Viscosity or to Saybolt Furol Viscosity

SIGNIFICANCE AND USE
4.1 At one time the petroleum industry relied on measuring kinematic viscosity by means of the Saybolt viscometer, and expressing kinematic viscosity in units of Saybolt Universal Seconds (SUS) and Saybolt Furol Seconds (SFS). This practice is now obsolete in the petroleum industry.  
4.2 This practice establishes the official equations relating SUS and SFS to the SI kinematic viscosity units, mm2/s.  
4.3 This practice allows for the conversion between SUS and SFS units and SI units of kinematic viscosity.
SCOPE
1.1 This practice2 covers the conversion tables and equations for converting kinematic viscosity in mm2/s at any temperature to Saybolt Universal viscosity in Saybolt Universal seconds (SUS) at the same temperature and for converting kinematic viscosity in mm2/s at 122 °F and 210 °F (50 °C and 98.9 °C) to Saybolt Furol viscosity in Saybolt Furol seconds (SFS) at the same temperatures. Kinematic viscosity values are based on water being 1.0034 mm2/s (cSt) at 68 °F (20 °C).  
Note 1: A fundamental and preferred method for measuring kinematic viscosity is by use of kinematic viscometers as outlined in Test Method D445. It is recommended that kinematic viscosity be reported in millimetres squared per second, instead of Saybolt Universal Seconds (SUS) or Saybolt Furol Seconds (SFS). This method is being retained for the purpose of calculation of kinematic viscosities from SUS and SFS data that appear in past literature. One millimetre squared per second (mm2/s) equals one centistoke (cSt), which is another unit commonly found in older literature.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for reference information purposes only. The SI unit of kinematic viscosity is mm2/s.  
1.2.1 Exception—Fahrenheit temperature units are used in this practice because they are accepted by industry for the type of legacy conversions described in this practice.  
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.

General Information

• Status: Historical
• Publication Date: 30-Jun-2016
• ICS: 17.060 - Measurement of volume, mass, density, viscosity
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.07 - Flow Properties

Relations

• Replaces: ASTM D2161-10e1 - Standard Practice for Conversion of Kinematic Viscosity to Saybolt Universal Viscosity or to Saybolt Furol Viscosity
• Effective Date: 01-Jul-2016
• Referred By: ASTM D88/D88M-07(2019)e1 - Standard Test Method for Saybolt Viscosity
• Effective Date: 01-Jul-2016
• Referred By: ASTM D8046-21 - Standard Guide for Pumpability of Heat Transfer Fluids
• Effective Date: 01-Jul-2016
• Referred By: ASTM D6074-15(2022) - Standard Guide for Characterizing Hydrocarbon Lubricant Base Oils
• Effective Date: 01-Jul-2016
• Referred By: ASTM D4731-13(2020) - Standard Specification for Hot-Application Filling Compounds for Telecommunications Wire and Cable
• Effective Date: 01-Jul-2016
• Referred By: ASTM D4732-13(2020) - Standard Specification for Cool-Application Filling Compounds for Telecommunications Wire and Cable
• Effective Date: 01-Jul-2016
• Referred By: ASTM D117-22 - Standard Guide for Sampling, Test Methods, and Specifications for Electrical Insulating Liquids
• Effective Date: 01-Jul-2016

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D2161 − 10 (Reapproved 2016)
Standard Practice for
Conversion of Kinematic Viscosity to Saybolt Universal
Viscosity or to Saybolt Furol Viscosity
This standard is issued under the fixed designation D2161; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2 3
1.1 This practice covers the conversion tables and equa- 2.1 ASTM Standards:
tions for converting kinematic viscosity in mm /s at any D445Test Method for Kinematic Viscosity of Transparent
temperature to Saybolt Universal viscosity in Saybolt Univer- and Opaque Liquids (and Calculation of DynamicViscos-
sal seconds (SUS) at the same temperature and for converting ity)
kinematic viscosity in mm /s at 122°F and 210°F (50°C and D2270Practice for Calculating Viscosity Index from Kine-
98.9°C) to Saybolt Furol viscosity in Saybolt Furol seconds matic Viscosity at 40°C and 100°C
(SFS)atthesametemperatures.Kinematicviscosityvaluesare 2.2 ASTM Adjunct:
based on water being 1.0034mm /s (cSt) at 68°F (20°C). ADJD2161Viscosity Extrapolation Tables to Zero Degrees
Fahrenheit (SSU)
NOTE1—Afundamentalandpreferredmethodformeasuringkinematic
viscosity is by use of kinematic viscometers as outlined in Test Method
3. Summary of Practice
D445. It is recommended that kinematic viscosity be reported in millime-
tres squared per second, instead of Saybolt Universal Seconds (SUS) or 3.1 The Saybolt Universal viscosity equivalent to a given
Saybolt Furol Seconds (SFS). This method is being retained for the
kinematic viscosity varies with the temperature at which the
purpose of calculation of kinematic viscosities from SUS and SFS data
determination is made. The basic conversion values are those
that appear in past literature. One millimetre squared per second (mm /s)
given in Table 1 for 100°F. The Saybolt Universal viscosity
equals one centistoke (cSt), which is another unit commonly found in
equivalent to a given kinematic viscosity at any temperature
older literature.
may be calculated as described in 4.3. Equivalent values at
1.2 The values stated in SI units are to be regarded as the
210°F are given in Table 1 for convenience.
standard. The values given in parentheses are provided for
reference information purposes only. The SI unit of kinematic 3.2 The Saybolt Furol viscosity equivalents are tabulated in
viscosity is mm /s. Table 3 for temperatures of 122°F and 210°F only.
1.2.1 Exception—Fahrenheit temperature units are used in
3.3 ExamplesforusingthetablesaregiveninAppendixX1.
this practice because they are accepted by industry for the type
4. Significance and Use
of legacy conversions described in this practice.
1.3 This standard does not purport to address all of the 4.1 At one time the petroleum industry relied on measuring
safety concerns, if any, associated with its use. It is the kinematic viscosity by means of the Saybolt viscometer, and
expressing kinematic viscosity in units of Saybolt Universal
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- Seconds(SUS)andSayboltFurolSeconds(SFS).Thispractice
is now obsolete in the petroleum industry.
bility of regulatory limitations prior to use.
4.2 This practice establishes the official equations relating
SUS and SFS to the SI kinematic viscosity units, mm /s.
This practice is under the jurisdiction ofASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
mittee D02.07 on Flow Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJuly1,2016.PublishedJuly2016.Originallyapproved contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
in 1963, replacing former D446 and D666. Last previous edition approved in 2010 Standards volume information, refer to the standard’s Document Summary page on
ɛ1
as D2161 – 10 . DOI: 10.1520/D2161-10R16. the ASTM website.
2 4
This practice, together with Practice D2270, replaces Compilation of ASTM Available from ASTM International Headquarters. Order Adjunct No.
Viscosity Tables for Kinematic Viscosity Conversions. ADJD2161. Original adjunct produced in 1998.
*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
D2161 − 10 (2016)
4.3 This practice allows for the conversion between SUS SayboltFurolsecondsat210°F (4)
and SFS units and SI units of kinematic viscosity.
5 0.4792 3mm /s ~cSt! at210°F
5. Procedure for Conversion to Saybolt Universal
Viscosity 7. Procedure for Computer Calculation
7.1 Table 1 and Table 3 were computed by fitting a smooth
5.1 Convert kinematic viscosities between 1.81mm /s and
2 2
500mm /s (cSt) at 100°F, and between 1.77mm /s and curve to the original experimental data points. The derived
139.8mm /s (cSt) at 210°F, to equivalent Saybolt Universal equations are given as follows for the convenience of those
seconds directly from Table 1 (see Appendix X1, Example 1). who wish to use a computer for conversion rather than refer to
the tables:
NOTE 2—Obtain viscosities not listed, but which are within the range
given in Table 1, by linear interpolation (see Appendix X1, Example 2). 1.010.03264v
U 5 4.6324ν1
100°F 2 3 25
3930.21262.7ν123.97ν 11.646ν 310
~ !
5.2 Convert kinematic viscosities greater than the upper
(5)
limits of Table 1 at temperatures of 100°F and 210°F to
Saybolt Universal viscosities as follows (see Appendix X1,
U 5 @1.010.000061~t 2 100!# (6)
t
Example 3):
1.010.03264ν
SayboltUniversalseconds 5 centistokes 3B (1)
· 4.6324ν1
F G
2 3 25
3930.21262.7ν123.97ν 11.646ν 310
~ !
where B=4.632 at 100°F or 4.664 at 210°F.
F 5 0.4717ν1 (7)
F G
122°F
5.3 At temperatures other than 100°F or 210°F, convert
ν 2 72.59ν16816
~ !
kinematic viscosities to Saybolt Universal viscosities as fol-
lows (see Appendix X1, Example 4): F 5 0.4792ν1 (8)
F G
210°F 2
~v 12130!
U 5 U ~110.000061~t 2 100!! (2)
t 100°F
where:
where:
ν = kinematic viscosity, mm /s (cSt) at t°F,
U = Saybolt Universal viscosity at t°F, and F = Saybolt Furol viscosity at 122°F in Saybolt Furol
t 122°F
U = Saybolt Universal viscosity at 100°F in Saybolt seconds equivalent to kinematic viscosity, mm /s
100°F
Universal seconds equivalent to kinematic viscos-
(cSt) at 122°F, and
ity in centistokes at t°F, from Table 1. F = Saybolt Furol viscosity at 210°F in Saybolt Furol
210°F
NOTE 3—The multipliers for Saybolt Universal seconds in Eq 2 are
seconds equivalent to kinematic viscosity, mm /s
given as Factor A in Table 2 for a range of temperatures.
(cSt) at 210°F.
5.4 Since the relationship between Saybolt and kinematic
7.2 Eq 5 and Eq 6 and Table 1 are limited to values of
viscositiesislinearabove75mm /s(cSt),kinematicviscosities
Saybolt Universal of 32.0s and above.
above this limit may be converted to Saybolt Universal
7.3 Eq 7 and Eq 8 and Table 3 are limited to values of
viscosities at any temperature between 0°F and 350°F by use
Saybolt Furol of 25.1s and above.
of Eq 1 (4.2), selecting the proper factor for B from Table 2
(see Appendix X1, Example 5).
8. Supplementary Conversion Equivalents
6. Procedure for Conversion to Saybolt Furol Viscosity
8.1 The following units and equivalents are frequently used
6.1 Convert kinematic viscosities between 48mm /s to in connection with viscosity conversions:
2 2
1300 mm /s (cSt) at 122 °F, and between 50 mm /s and
poise = cgs unit of absolute viscosity.
centipoise = 0.01 poise.
1300mm /s(cSt) at 210°F, to equivalent Saybolt Furol sec-
stokes = cgs unit of kinematic viscosity.
onds directly from Table 3 (see Appendix X1, Examples 6 and
centistokes = 0.01 stokes.
7).
centipoise = centistokes × density (at temperature under
consideration).
NOTE 4—Viscosities not listed, but which are within the range given in
Table 3, may be obtained by linear interpolation (see Appendix X1,
9. Report
Example 8).
9.1 Saybolt Universal and Saybolt Furol viscosities should
6.2 Convertkinematicviscositiesabove1300cSttoequiva-
be reported to the nearest 0.1s for values below 200s and to
lent Saybolt Furol seconds by use of the following equations
the nearest whole second for values of 200s and higher.
(see Appendix X1, Example 9):
SayboltFurolsecondsat122°F (3)
10. Keywords
5 0.4717 3mm /s ~cSt! at122°F 10.1 kinematic viscosity; Saybolt furol; Saybolt universal
D2161 − 10 (2016)
TABLE 1 Kinematic Viscosity to Saybolt Universal Viscosity
2 2
1.77 mm /s to 500.0 mm /s (cSt)
Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt
2 2 2 2
mm /s Universal mm /s Universal mm /s Universal mm /s Universal
(cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS
At 100 °F At 210 °F At 100 °F At 210 °F At 100 °F At 210 °F At 100 °F At 210 °F
2.25 33.5 33.7 2.75 35.1 35.4 3.25 36.8 37.0
2.26 33.5 33.7 2.76 35.2 35.4 3.26 36.8 37.0
1.77 . . 32.0 2.27 33.5 33.7 2.77 35.2 35.4 3.27 36.8 37.1
1.78 . . 32.1 2.28 33.6 33.8 2.78 35.2 35.5 3.28 36.9 37.1
1.79 . . 32.1 2.29 33.6 33.8 2.79 35.3 35.5 3.29 36.9 37.1
1.80 . . 32.1 2.30 33.6 33.8 2.80 35.3 35.5 3.30 36.9 37.2
1.81 32.0 32.2 2.31 33.7 33.9 2.81 35.3 35.6 3.31 37.0 37.2
1.82 32.0 32.2 2.32 33.7 33.9 2.81 35.4 35.6 3.32 37.0 37.2
1.83 32.0 32.2 2.33 33.7 33.9 2.83 35.4 35.6 3.33 37.0 37.3
1.84 32.1 32.3 2.34 33.8 34.0 2.84 35.4 35.7 3.34 37.1 37.3
1.85 32.1 32.3 2.35 33.8 34.0 2.85 35.5 35.7 3.35 37.1 37.3
1.86 32.1 32.3 2.36 33.8 34.0 2.86 35.5 35.7 3.36 37.1 37.4
1.87 32.2 32.4 2.37 33.9 34.1 2.87 35.5 35.8 3.37 37.2 37.4
1.88 32.2 32.4 2.38 33.9 34.1 2.88 35.6 35.8 3.38 37.2 37.4
1.89 32.2 32.4 2.39 33.9 34.2 2.89 35.6 35.8 3.39 37.2 37.5
1.90 32.3 32.5 2.40 34.0 34.2 2.90 35.6 35.9 3.40 37.3 37.5
1.91 32.3 32.5 2.41 34.0 34.2 2.91 35.7 35.9 3.41 37.3 37.5
1.92 32.3 32.5 2.42 34.0 34.3 2.92 35.7 35.9 3.42 37.3 37.6
1.93 32.4 32.6 2.43 34.1 34.3 2.93 35.7 36.0 3.43 37.4 37.6
1.94 32.4 32.6 2.44 34.1 34.3 2.94 35.8 36.0 3.44 37.4 37.6
1.95 32.4 32.6 2.45 34.1 34.4 2.95 35.8 36.0 3.45 37.4 37.7
1.96 32.5 32.7 2.46 34.2 34.4 2.96 35.8 36.1 3.46 37.5 37.7
1.97 32.5 32.7 2.47 34.2 34.4 2.97 35.9 36.1 3.47 37.5 37.7
1.98 32.5 32.8 2.48 34.2 34.5 2.98 35.9 36.1 3.48 37.5 37.8
1.99 32.6 32.8 2.49 34.3 34.5 2.99 35.9 36.2 3.49 37.6 37.8
2.00 32.6 32.8 2.50 34.3 34.5 3.00 36.0 36.2 3.50 37.6 37.8
2.01 32.6 32.9 2.51 34.3 34.6 3.01 36.0 36.2 3.51 37.6 37.9
2.02 32.7 32.9 2.52 34.4 34.6 3.02 36.0 36.3 3.52 37.6 37.9
2.03 32.7 32.9 2.53 34.4 34.6 3.03 36.0 36.3 3.53 37.7 37.9
2.04 32.7 33.0 2.54 34.4 34.7 3.04 36.1 36.3 3.54 37.7 38.0
2.05 32.8 33.0 2.55 34.5 34.7 3.05 36.1 36.4 3.55 37.7 38.0
2.06 32.8 33.0 2.56 34.5 34.7 3.06 36.1 36.4 3.56 37.8 38.0
2.07 32.8 33.1 2.57 34.5 34.8 3.07 36.2 36.4 3.57 37.8 38.1
2.08 32.9 33.1 2.58 34.6 34.8 3.08 36.2 36.5 3.58 37.8 38.1
2.09 32.9 33.1 2.59 34.6 34.8 3.09 36.2 36.5 3.59 37.9 38.1
2.10 32.9 33.2 2.60 34.6 34.9 3.10 36.3 36.5 3.60 37.9 38.2
2.11 33.0 33.2 2.61 34.7 34.9 3.11 36.3 36.6 3.61 37.9 38.2
2.12 33.0 33.2 2.62 34.7 34.9 3.12 36.3 36.6 3.62 38.0 38.2
2.13 33.0 33.3 2.63 34.7 35.0 3.13 36.4 36.6 3.63 38.0 38.3
2.14 33.1 33.3 2.64 34.8 35.0 3.14 36.4 36.7 3.64 38.0 38.3
2.15 33.1 33.3 2.65 34.8 35.0 3.15 36.4 36.7 3.65 38.1 38.3
2.16 33.1 33.4 2.66 34.8 35.1 3.16 36.5 36.7 3.66 38.1 38.4
2.17 33.2 33.4 2.67 34.9 35.1 3.17 36.5 36.8 3.67 38.1 38.4
2.18 33.2 33.4 2.68 34.9 35.1 3.18 36.5 36.8 3.68 38.2 38.4
2.19 33.2 33.5 2.69 34.9 35.2 3.19 36.6 36.8 3.69 38.2 38.5
2.20 33.3 33.5 2.70 35.0 35.2 3.20 36.6 36.9 3.70 38.2 38.5
2.21 33.3 33.5 2.71 35.0 35.2 3.21 36.6 36.9 3.71 38.3 38.5
2.22 33.3 33.6 2.72 35.0 35.3 3.22 36.7 36.9 3.72 38.3 38.6
2.23 33.4 33.6 2.73 35.1 35.3 3.23 36.7 37.0 3.73 38.3 38.6
2.24 33.4 33.6 2.74 35.1 35.3 3.24 36.7 37.0 3.74 38.4 38.6
D2161 − 10 (2016)
TABLE 1 Continued
Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt
2 2 2 2
mm /s Universal mm /s Universal mm /s Universal mm /s Universal
(cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS
At 100 °F At 210 °F At 100 °F At 210 °F At 100 °F At 210 °F At 100 °F At 210 °F
3.75 38.4 38.7 4.25 40.0 40.3 4.75 41.6 41.9 5.25 43.2 43.5
3.76 38.4 38.7 4.26 40.0 40.3 4.76 41.6 41.9 5.26 43.2 43.5
3.77 38.5 38.7 4.27 40.1 40.3 4.77 41.7 41.9 5.27 43.3 43.5
3.78 38.5 38.7 4.28 40.1 40.4 4.78 41.7 42.0 5.28 43.3 43.6
3.79 38.5 38.8 4.29 40.1 40.4 4.79 41.7 42.0 5.29 43.3 43.6
3.80 38.6 38.8 4.30 40.2 40.4 4.80 41.8 42.0 5.30 43.3 43.6
3.81 38.6 38.8 4.31 40.2 40.5 4.81 41.8 42.1 5.31 43.4 43.7
3.82 38.6 38.9 4.32 40.2 40.5 4.82 41.8 42.1 5.32 43.4 43.7
3.83 38.7 38.9 4.33 40.3 40.5 4.83 41.9 42.1 5.33 43.4 43.7
3.84 38.7 38.9 4.34 40.3 40.6 4.84 41.9 42.2 5.34 43.5 43.8
3.85 38.7 39.0 4.35 40.3 40.6 4.85 41.9 42.2 5.35 43.5 43.8
3.86 38.7 39.0 4.36 40.4 40.6 4.86 41.9 42.2 5.36 43.5 43.8
3.87 38.8 39.0 4.37 40.4 40.7 4.87 42.0 42.3 5.37 43.6 43.9
3.88 38.8 39.1 4.38 40.4 40.7 4.88 42.0 42.3 5.38 43.6 43.9
3.89 38.8 39.1 4.39 40.4 40.7 4.89 42.0 42.3 5.39 43.6 43.9
3.90 38.9 39.1 4.40 40.5 40.8 4.90 42.1 42.4 5.40 43.7 44.0
3.91 38.9 39.2 4.41 40.5 40.8 4.91 42.1 42.4 5.41 43.7 44.0
3.92 38.9 39.2 4.42 40.5 40.8 4.92 42.1 42.4 5.42 43.7 44.0
3.93 39.0 39.2 4.43 40.6 40.8 4.93 42.2 42.5 5.43 43.8 44.1
3.94 39.0 39.3 4.44 40.6 40.9 4.94 42.2 42.5 5.44 43.8 44.1
3.95 39.0 39.3 4.45 40.6 40.9 4.95 42.2 42.5 5.45 43.8 44.1
3.96 39.1 39.3 4.46 40.7 40.9 4.96 42.3 42.5 5.46 43.9 44.2
3.97 39.1 39.4 4.47 40.7 41.0 4.97 42.3 42.6 5.47 43.9 44.2
3.98 39.1 39.4 4.48 40.7 41.0 4.98 42.3 42.6 5.48 43.9 44.2
3.99 39.2 39.4 4.49 40.8 41.0 4.99 42.4 42.6 5.49 44.0 44.2
4.00 39.2 39.5 4.50 40.8 41.1 5.00 42.4 42.7 5.50 44.0 44.3
4.01 39.2 39.5 4.51 40.8 41.1 5.01 42.4 42.7 5.51 44.0 44.3
4.02 39.3 39.5 4.52 40.9 41.1 5.02 42.5 42.7 5.52 44.0 44.3
4.03 39.3 39.6 4.53 40.9 41.2 5.03 42.5 42.8 5.53 44.1 44.4
4.04 39.3 39.6 4.54 40.9 41.2 5.04 42.5 42.8 5.54 44.1 44.4
4.05 39.4 39.6 4.55 41.0 41.2 5.05 42.6 42.8 5.55 44.1 44.4
4.06 39.4 39.7 4.56 41.0 41.3 5.06 42.6 42.9 5.56 44.2 44.5
4.07 39.4 39.7 4.57 41.0 41.3 5.07 42.6 42.9 5.57 44.2 44.5
4.08 39.5 39.7 4.58 41.1 41.3 5.08 42.6 42.9 5.58 44.2 44.5
4.09 39
...

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.
´1
Designation: D2161 − 10 D2161 − 10 (Reapproved 2016)
Standard Practice for
Conversion of Kinematic Viscosity to Saybolt Universal
Viscosity or to Saybolt Furol Viscosity
This standard is issued under the fixed designation D2161; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—The format of continuing Table 1 was corrected editorially in September 2015.
1. Scope*Scope
2 2
1.1 This practice covers the conversion tables and equations for converting kinematic viscosity in mm /s at any temperature
to Saybolt Universal viscosity in Saybolt Universal seconds (SUS) at the same temperature and for converting kinematic viscosity
in mm /s at 122122 °F and 210°F (50210 °F (50 °C and 98.9°C)98.9 °C) to Saybolt Furol viscosity in Saybolt Furol seconds (SFS)
at the same temperatures. Kinematic viscosity values are based on water being 1.0034 mm1.0034 mm /s (cSt) at 68°F (20°C).68 °F
(20 °C).
NOTE 1—A fundamental and preferred method for measuring kinematic viscosity is by use of kinematic viscometers as outlined in Test Method D445.
It is recommended that kinematic viscosity be reported in millimetres squared per second, instead of Saybolt Universal Seconds (SUS) or Saybolt Furol
Seconds (SFS). This method is being retained for the purpose of calculation of kinematic viscosities from SUS and SFS data that appear in past literature.
One millimetre squared per second (mm /s) equals one centistoke (cSt), which is another unit commonly found in older literature.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are provided for reference
information purposes only. The SI unit of kinematic viscosity is mm /s.
1.2.1 Exception—Fahrenheit temperature units are used in this practice because they are accepted by industry for the type of
legacy conversions described in this practice.
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.
2. Referenced Documents
2.1 ASTM Standards:
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D2270 Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 °C and 100 °C
2.2 ASTM Adjunct:
ADJD2161 Viscosity Extrapolation Tables to Zero Degrees Fahrenheit (SSU)
3. Summary of Practice
3.1 The Saybolt Universal viscosity equivalent to a given kinematic viscosity varies with the temperature at which the
determination is made. The basic conversion values are those given in Table 1 for 100°F.100 °F. The Saybolt Universal viscosity
equivalent to a given kinematic viscosity at any temperature may be calculated as described in 4.3. Equivalent values at
210°F210 °F are given in Table 1 for convenience.
3.2 The Saybolt Furol viscosity equivalents are tabulated in Table 3 for temperatures of 122°F122 °F and 210°F210 °F only.
This practice is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.07 on Flow Properties.
Current edition approved Oct. 1, 2010July 1, 2016. Published November 2010July 2016. Originally approved in 1963, replacing former D446 and D666. Last previous
ε1ɛ1
edition approved in 20052010 as D2161–05 – 10 . DOI: 10.1520/D2161-10E01.10.1520/D2161-10R16.
This practice, together with Practice D2270, replaces Compilation of ASTM Viscosity Tables for Kinematic Viscosity Conversions.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from ASTM International Headquarters. Order Adjunct No. ADJD2161. Original adjunct produced in 1998.
*A Summary of Changes section appears at the end of this standard
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D2161 − 10 (2016)
3.3 Examples for using the tables are given in Appendix X1.
4. Significance and Use
4.1 At one time the petroleum industry relied on measuring kinematic viscosity by means of the Saybolt viscometer, and
expressing kinematic viscosity in units of Saybolt Universal Seconds (SUS) and Saybolt Furol Seconds (SFS). This practice is now
obsolete in the petroleum industry.
4.2 This practice establishes the official equations relating SUS and SFS to the SI kinematic viscosity units, mm /s.
4.3 This practice allows for the conversion between SUS and SFS units and SI units of kinematic viscosity.
5. Procedure for Conversion to Saybolt Universal Viscosity
2 2
5.1 Convert kinematic viscosities between 1.811.81 mm /s and 500 mm500 mm /s (cSt) at 100°F,100 °F, and between
2 2
1.771.77 mm /s and 139.8 mm139.8 mm /s (cSt) at 210°F,210 °F, to equivalent Saybolt Universal seconds directly from Table 1
(see Appendix X1, Example 1).
NOTE 2—Obtain viscosities not listed, but which are within the range given in Table 1, by linear interpolation (see Appendix X1, Example 2).
5.2 Convert kinematic viscosities greater than the upper limits of Table 1 at temperatures of 100100 °F and 210°F210 °F to
Saybolt Universal viscosities as follows (see Appendix X1, Example 3):
Saybolt Universal seconds 5 centistokes 3B (1)
where B = 4.632 at 100°F100 °F or 4.664 at 210°F.210 °F.
5.3 At temperatures other than 100100 °F or 210°F,210 °F, convert kinematic viscosities to Saybolt Universal viscosities as
follows (see Appendix X1, Example 4):
U 5 U ~110.000061~t 2 100!! (2)
t 100°F
where:
U = Saybolt Universal viscosity at t°F, and
t
U = Saybolt Universal viscosity at 100°F in Saybolt Universal seconds equivalent to kinematic viscosity in centistokes at
100°F
t°F, from Table 1.
NOTE 3—The multipliers for Saybolt Universal seconds in Eq 2 are given as Factor A in Table 2 for a range of temperatures.
5.4 Since the relationship between Saybolt and kinematic viscosities is linear above 75 mm75 mm /s (cSt), kinematic viscosities
above this limit may be converted to Saybolt Universal viscosities at any temperature between 00 °F and 350°F350 °F by use of
Eq 1 (4.2), selecting the proper factor for B from Table 2 (see Appendix X1, Example 5).
6. Procedure for Conversion to Saybolt Furol Viscosity
2 2 2
6.1 Convert kinematic viscosities between 4848 mm /s to 1300 mm1300 mm /s (cSt) at 122°F,122 °F, and between 5050 mm /s
and 1300 mm1300 mm /s (cSt) at 210°F,210 °F, to equivalent Saybolt Furol seconds directly from Table 3 (see Appendix X1,
Examples 6 and 7).
NOTE 4—Viscosities not listed, but which are within the range given in Table 3, may be obtained by linear interpolation (see Appendix X1, Example
8).
6.2 Convert kinematic viscosities above 1300 cSt 1300 cSt to equivalent Saybolt Furol seconds by use of the following
equations (see Appendix X1, Example 9):
Saybolt Furol seconds at 122°F (3)
5 0.4717 3mm /s ~cSt! at 122°F
Saybolt Furol seconds at 210°F (4)
5 0.4792 3mm /s cSt at 210°F
~ !
7. Procedure for Computer Calculation
7.1 Table 1 and Table 3 were computed by fitting a smooth curve to the original experimental data points. The derived equations
are given as follows for the convenience of those who wish to use a computer for conversion rather than refer to the tables:
1.010.03264v
U 5 4.6324ν1 (5)
100°F 2 3 25
3930.21262.7ν123.97ν 11.646ν 310
~ !
U 5 @1.010.000061~t 2 100!# (6)
t
1.010.03264ν
· 4.6324ν1
F G
2 3 25
3930.21262.7ν123.97ν 11.646ν 310
~ !
D2161 − 10 (2016)
F 5 0.4717ν1 (7)
F G
122°F 2
~ν 2 72.59ν16816!
F 5 0.4792ν1 (8)
F G
210°F 2
v 12130
~ !
where:
ν = kinematic viscosity, mm /s (cSt) at t°F,
F = Saybolt Furol viscosity at 122°F in Saybolt Furol seconds equivalent to kinematic viscosity, mm /s (cSt) at 122°F, and
122°F
F = Saybolt Furol viscosity at 122 °F in Saybolt Furol seconds equivalent to kinematic viscosity, mm /s (cSt) at 122 °F, and
122°F
F = Saybolt Furol viscosity at 210°F in Saybolt Furol seconds equivalent to kinematic viscosity, mm /s (cSt) at 210°F.
210°F
F = Saybolt Furol viscosity at 210 °F in Saybolt Furol seconds equivalent to kinematic viscosity, mm /s (cSt) at 210 °F.
210°F
7.2 Eq 5 and Eq 6 and Table 1 are limited to values of Saybolt Universal of 32.0 s 32.0 s and above.
7.3 Eq 7 and Eq 8 and Table 3 are limited to values of Saybolt Furol of 25.1 s 25.1 s and above.
8. Supplementary Conversion Equivalents
8.1 The following units and equivalents are frequently used in connection with viscosity conversions:
poise = cgs unit of absolute viscosity.
centipoise = 0.01 poise.
stokes = cgs unit of kinematic viscosity.
centistokes = 0.01 stokes.
centipoise = centistokes × density (at temperature under
consideration).
9. Report
9.1 Saybolt Universal and Saybolt Furol viscosities should be reported to the nearest 0.1 s 0.1 s for values below 200 s 200 s
and to the nearest whole second for values of 200 s 200 s and higher.
10. Keywords
10.1 kinematic viscosity; Saybolt furol; Saybolt universal
D2161 − 10 (2016)
TABLE 1 Kinematic Viscosity to Saybolt Universal Viscosity
2 2
1.771.77 mm /s to 500.0 mm /s (cSt)
Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt
2 2 2 2
mm /s Universal mm /s Universal mm /s Universal mm /s Universal
(cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS
At At At At At At At At
100°F100 °F 210°F210 °F 100°F100 °F 210°F210 °F 100°F100 °F 210°F210 °F 100°F100 °F 210°F210 °F
2.25 33.5 33.7 2.75 35.1 35.4 3.25 36.8 37.0
2.26 33.5 33.7 2.76 35.2 35.4 3.26 36.8 37.0
1.77 . . 32.0 2.27 33.5 33.7 2.77 35.2 35.4 3.27 36.8 37.1
1.78 . . 32.1 2.28 33.6 33.8 2.78 35.2 35.5 3.28 36.9 37.1
1.79 . . 32.1 2.29 33.6 33.8 2.79 35.3 35.5 3.29 36.9 37.1
1.80 . . 32.1 2.30 33.6 33.8 2.80 35.3 35.5 3.30 36.9 37.2
1.81 32.0 32.2 2.31 33.7 33.9 2.81 35.3 35.6 3.31 37.0 37.2
1.82 32.0 32.2 2.32 33.7 33.9 2.81 35.4 35.6 3.32 37.0 37.2
1.83 32.0 32.2 2.33 33.7 33.9 2.83 35.4 35.6 3.33 37.0 37.3
1.84 32.1 32.3 2.34 33.8 34.0 2.84 35.4 35.7 3.34 37.1 37.3
1.85 32.1 32.3 2.35 33.8 34.0 2.85 35.5 35.7 3.35 37.1 37.3
1.86 32.1 32.3 2.36 33.8 34.0 2.86 35.5 35.7 3.36 37.1 37.4
1.87 32.2 32.4 2.37 33.9 34.1 2.87 35.5 35.8 3.37 37.2 37.4
1.88 32.2 32.4 2.38 33.9 34.1 2.88 35.6 35.8 3.38 37.2 37.4
1.89 32.2 32.4 2.39 33.9 34.2 2.89 35.6 35.8 3.39 37.2 37.5
1.90 32.3 32.5 2.40 34.0 34.2 2.90 35.6 35.9 3.40 37.3 37.5
1.91 32.3 32.5 2.41 34.0 34.2 2.91 35.7 35.9 3.41 37.3 37.5
1.92 32.3 32.5 2.42 34.0 34.3 2.92 35.7 35.9 3.42 37.3 37.6
1.93 32.4 32.6 2.43 34.1 34.3 2.93 35.7 36.0 3.43 37.4 37.6
1.94 32.4 32.6 2.44 34.1 34.3 2.94 35.8 36.0 3.44 37.4 37.6
1.95 32.4 32.6 2.45 34.1 34.4 2.95 35.8 36.0 3.45 37.4 37.7
1.96 32.5 32.7 2.46 34.2 34.4 2.96 35.8 36.1 3.46 37.5 37.7
1.97 32.5 32.7 2.47 34.2 34.4 2.97 35.9 36.1 3.47 37.5 37.7
1.98 32.5 32.8 2.48 34.2 34.5 2.98 35.9 36.1 3.48 37.5 37.8
1.99 32.6 32.8 2.49 34.3 34.5 2.99 35.9 36.2 3.49 37.6 37.8
2.00 32.6 32.8 2.50 34.3 34.5 3.00 36.0 36.2 3.50 37.6 37.8
2.01 32.6 32.9 2.51 34.3 34.6 3.01 36.0 36.2 3.51 37.6 37.9
2.02 32.7 32.9 2.52 34.4 34.6 3.02 36.0 36.3 3.52 37.6 37.9
2.03 32.7 32.9 2.53 34.4 34.6 3.03 36.0 36.3 3.53 37.7 37.9
2.04 32.7 33.0 2.54 34.4 34.7 3.04 36.1 36.3 3.54 37.7 38.0
2.05 32.8 33.0 2.55 34.5 34.7 3.05 36.1 36.4 3.55 37.7 38.0
2.06 32.8 33.0 2.56 34.5 34.7 3.06 36.1 36.4 3.56 37.8 38.0
2.07 32.8 33.1 2.57 34.5 34.8 3.07 36.2 36.4 3.57 37.8 38.1
2.08 32.9 33.1 2.58 34.6 34.8 3.08 36.2 36.5 3.58 37.8 38.1
2.09 32.9 33.1 2.59 34.6 34.8 3.09 36.2 36.5 3.59 37.9 38.1
2.10 32.9 33.2 2.60 34.6 34.9 3.10 36.3 36.5 3.60 37.9 38.2
2.11 33.0 33.2 2.61 34.7 34.9 3.11 36.3 36.6 3.61 37.9 38.2
2.12 33.0 33.2 2.62 34.7 34.9 3.12 36.3 36.6 3.62 38.0 38.2
2.13 33.0 33.3 2.63 34.7 35.0 3.13 36.4 36.6 3.63 38.0 38.3
2.14 33.1 33.3 2.64 34.8 35.0 3.14 36.4 36.7 3.64 38.0 38.3
2.15 33.1 33.3 2.65 34.8 35.0 3.15 36.4 36.7 3.65 38.1 38.3
2.16 33.1 33.4 2.66 34.8 35.1 3.16 36.5 36.7 3.66 38.1 38.4
2.17 33.2 33.4 2.67 34.9 35.1 3.17 36.5 36.8 3.67 38.1 38.4
2.18 33.2 33.4 2.68 34.9 35.1 3.18 36.5 36.8 3.68 38.2 38.4
2.19 33.2 33.5 2.69 34.9 35.2 3.19 36.6 36.8 3.69 38.2 38.5
2.20 33.3 33.5 2.70 35.0 35.2 3.20 36.6 36.9 3.70 38.2 38.5
2.21 33.3 33.5 2.71 35.0 35.2 3.21 36.6 36.9 3.71 38.3 38.5
2.22 33.3 33.6 2.72 35.0 35.3 3.22 36.7 36.9 3.72 38.3 38.6
2.23 33.4 33.6 2.73 35.1 35.3 3.23 36.7 37.0 3.73 38.3 38.6
2.24 33.4 33.6 2.74 35.1 35.3 3.24 36.7 37.0 3.74 38.4 38.6
D2161 − 10 (2016)
TABLE 1 Continued
Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt Kin Vis, Equivalent Saybolt
2 2 2 2
mm /s Universal mm /s Universal mm /s Universal mm /s Universal
(cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS (cSt) Viscosity, SUS
At At At At At At At At
100°F100 °F 210°F210 °F 100°F100 °F 210°F210 °F 100°F100 °F 210°F210 °F 100°F100 °F 210°F210 °F
3.75 38.4 38.7 4.25 40.0 40.3 4.75 41.6 41.9 5.25 43.2 43.5
3.76 38.4 38.7 4.26 40.0 40.3 4.76 41.6 41.9 5.26 43.2 43.5
3.77 38.5 38.7 4.27 40.1 40.3 4.77 41.7 41.9 5.27 43.3 43.5
3.78 38.5 38.7 4.28 40.1 40.4 4.78 41.7 42.0 5.28 43.3 43.6
3.79 38.5 38.8 4.29 40.1 40.4 4.79 41.7 42.0 5.29 43.3 43.6
3.80 38.6 38.8 4.30 40.2 40.4 4.80 41.8 42.0 5.30 43.3 43.6
3.81 38.6 38.8 4.31 40.2 40.5 4.81 41.8 42.1 5.31 43.4 43.7
3.82 38.6 38.9 4.32 40.2 40.5 4.82 41.8 42.1 5.32 43.4 43.7
3.83 38.7 38.9 4.33 40.3 40.5 4.83 41.9 42.1 5.33 43.4 43.7
3.84 38.7 38.9 4.34 40.3 40.6 4.84 41.9 42.2 5.34 43.5 43.8
3.85 38.7 39.0 4.35 40.3 40.6 4.85 41.9 42.2 5.35 43.5 43.8
3.86 38.7 39.0 4.36 40.4 40.6 4.86 41.9 42.2 5.36 43.5 43.8
3.87 38.8 39.0 4.37 40.4 40.7 4.87 42.0 42.3 5.37 43.6 43.9
3.88 38.8 39.1 4.38 40.4 40.7 4.88 42.0 42.3 5.38 43.6 43.9
3.89 38.8 39.1 4.39 40.4 40.7 4.89 42.0 42.3
...