ASTM E29-13(2019)

Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

ABSTRACT
This practice is intended to assist the various technical committees in the use of uniform methods of indicating the number of digits which are to be considered significant in specification limits, for example, specified maximum values and specified minimum values. This practice is also intended to be used in determining conformance with specifications when the applicable ASTM specifications or standards make a direct reference.
This practice describes absolute method and the rounding method. The absolute method applies where it is the intent that all digits in an observed value or a calculated value are to be considered significant for purposes of determining conformance with specifications, while the rounding method applies where it is the intent that a limited number of digits in an observed value or a calculated value are to be considered significant for purposes of determining conformance with specifications.
SCOPE
1.1 This practice is intended to assist the various technical committees in the use of uniform methods of indicating the number of digits which are to be considered significant in specification limits, for example, specified maximum values and specified minimum values. Its aim is to outline methods which should aid in clarifying the intended meaning of specification limits with which observed values or calculated test results are compared in determining conformance with specifications.  
1.2 This practice is intended to be used in determining conformance with specifications when the applicable ASTM specifications or standards make direct reference to this practice.  
1.3 Reference to this practice is valid only when a choice of method has been indicated, that is, either absolute method or rounding method.  
1.4 The system of units for this practice is not specified. Dimensional quantities in the practice are presented only as illustrations of calculation methods. The examples are not binding on products or test methods treated.  
1.5 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.  
1.6 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.

General Information

• Status: Historical
• Publication Date: 31-Dec-2018
• ICS: 17.020 - Metrology and measurement in general
• ICS: 19.020 - Test conditions and procedures in general
• Technical Committee: E11 - Quality and Statistics
• Drafting Committee: E11.30 - Statistical Quality Control

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:E29 −13 (Reapproved 2019) An American National Standard
Standard Practice for
Using Significant Digits in Test Data to Determine
Conformance with Specifications
ThisstandardisissuedunderthefixeddesignationE29;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
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
2.1 ASTM Standards:
1.1 This practice is intended to assist the various technical
E177Practice for Use of the Terms Precision and Bias in
committees in the use of uniform methods of indicating the
ASTM Test Methods
number of digits which are to be considered significant in
E456Terminology Relating to Quality and Statistics
specification limits, for example, specified maximum values
E2282Guide for Defining the Test Result of a Test Method
and specified minimum values. Its aim is to outline methods
IEEE/ASTMSI10Standard for Use of the International
which should aid in clarifying the intended meaning of
System of Units (SI): The Modern Metric System
specification limits with which observed values or calculated
test results are compared in determining conformance with
3. Terminology
specifications.
3.1 Definitions—Terminology E456 provides a more exten-
1.2 This practice is intended to be used in determining
sive list of terms in E11 standards.
conformance with specifications when the applicable ASTM
3.1.1 observed value, n—the value obtained by making an
specifications or standards make direct reference to this prac-
observation. E2282
tice.
3.1.2 repeatability conditions, n—conditions where inde-
1.3 Referencetothispracticeisvalidonlywhenachoiceof
pendent test results are obtained with the same method on
method has been indicated, that is, either absolute method or
identicaltestitemsinthesamelaboratorybythesameoperator
rounding method.
using the same equipment within short intervals of time. E177
1.4 The system of units for this practice is not speci-
3.1.3 repeatability standard deviation (s ), n—the standard
r
fied. Dimensional quantities in the practice are presented only
deviation of test results obtained under repeatability
as illustrations of calculation methods. The examples are not
conditions. E177
binding on products or test methods treated.
3.1.4 significant digit—any of the figures 0 through 9 that is
1.5 This standard does not purport to address all of the
used with its place value to denote a numerical quantity to
safety concerns, if any, associated with its use. It is the
some desired approximation, excepting all leading zeros and
responsibility of the user of this standard to establish appro-
some trailing zeros in numbers not represented with a decimal
priate safety, health, and environmental practices and deter-
point.
mine the applicability of regulatory limitations prior to use.
3.1.4.1 Discussion—This definition of significant digits re-
1.6 This international standard was developed in accor- lates to how the number is represented as a decimal. It should
dance with internationally recognized principles on standard- not be inferred that a measurement value is precise to the
ization established in the Decision on Principles for the number of significant digits used to represent it.
Development of International Standards, Guides and Recom- 3.1.4.2 Discussion—The digit zero may either indicate a
mendations issued by the World Trade Organization Technical specific value or indicate place only. Zeros leading the first
Barriers to Trade (TBT) Committee. nonzerodigitofanumberindicateorderofmagnitudeonlyand
are not significant digits. For example, the number 0.0034 has
two significant digits. Zeros trailing the last nonzero digit for
ThispracticeisunderthejurisdictionofASTMCommitteeE11onQualityand
Statistics and is the direct responsibility of Subcommittee E11.30 on Statistical
Quality Control. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2019. Published January 2019. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1940. Last previous edition approved in 2013 as E29–13. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E0029-13R19. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E29−13 (2019)
numbersrepresentedwithadecimalpointaresignificantdigits. 4.2 Section 7 of this practice gives guidelines for use in
For example, the numbers 1270. and 32.00 each have four recording, calculating, and reporting the final result for test
significantdigits.Thesignificanceoftrailingzerosfornumbers data.
represented without use of a decimal point can only be
identified from knowledge of the source of the value. For 5. Absolute Method
example, a modulus strength, stated as 140000 Pa, may have
5.1 Where Applicable—The absolute method applies where
as few as two or as many as six significant digits.
itistheintentthatalldigitsinanobservedvalueoracalculated
3.1.4.3 Discussion—To eliminate ambiguity, the exponen-
value are to be considered significant for purposes of deter-
tial notation may be used. Thus, 1.40×10 indicates that the
mining conformance with specifications. Under these
modulus is reported to the nearest 0.01×10 or 1000 Pa.
conditions, the specified limits are referred to as absolute
limits.
3.1.4.4 Discussion—Use of appropriate SI prefixes is rec-
ommendedformetricunitstoreducetheneedfortrailingzeros
5.2 How Applied—With the absolute method, an observed
of uncertain significance. Thus, 140 kPa (without the decimal
value or a calculated value is not to be rounded, but is to be
point) indicates that the modulus is reported either to the
compared directly with the specified limiting value. Confor-
nearest 10 or 1 kPa, which is ambiguous with respect to the
mance or nonconformance with the specification is based on
number of significant digits. However, 0.140 MPa clearly
this comparison.
indicates that the modulus is reported to the nearest 1 kPa, and
5.3 How Expressed—This intent may be expressed in the
0.14 MPa clearly indicates that the modulus is reported to the
standard in one of the following forms:
nearest 10 kPa.
5.3.1 Iftheabsolutemethodistoapplytoallspecifiedlimits
3.1.5 test result, n—thevalueofacharacteristicobtainedby
in the standard, this may be indicated by including the
carrying out a specified test method. E2282
following sentence in the standard:
For purposes of determining conformance with these specifications, all
4. Significance and Use
specified limits in this standard are absolute limits, as defined in ASTM Practice
E29, for Using Significant Digits in Test Data to Determine Conformance with
4.1 This practice describes two commonly accepted meth-
Specifications.
odsofroundingdata,identifiedastheAbsoluteMethodandthe
5.3.2 Iftheabsolutemethodistoapplytoallspecifiedlimits
Rounding Method. In the applications of this practice to a
of some general type in the standard (such as dimensional
specific material or materials it is essential to specify which
tolerance limits), this may be indicated by including the
method is intended to apply. In the absence of such
following sentence in the standard:
specification, reference to this practice, which expresses no
For purposes of determining conformance with these specifications, all
preference as to which method should apply, would be mean-
specified (dimensional tolerance) limits are absolute limits, as defined in ASTM
Practice E29, for Using Significant Digits in Test Data to Determine Confor-
ingless. The choice of method depends upon the current
mance with Specifications.
practice of the particular branch of industry or technology
5.3.3 Iftheabsolutemethodistoapplytoallspecifiedlimits
concerned, and should therefore be specified in the prime
given in a table, this may be indicated by including a footnote
publication.
with the table as follows:
4.1.1 Theunqualifiedstatementofanumericallimit,suchas
A
Capacity
“2.50 in. max,” cannot, in view of different established Volumetric Tolerance
mL ±mL
practices and customs, be regarded as carrying a definite
operational meaning concerning the number of digits to be
10 0.02
25 0.03
retained in an observed or a calculated value for purposes of
50 0.05
determining conformance with specifications.
100 0.10
4.1.2 Absolute Method—In some fields, specification limits
A
TolerancelimitsspecifiedareabsolutelimitsasdefinedinPracticeE29,forUsing
of 2.5 in. max, 2.50 in. max, and 2.500 in. max are all taken to
Significant Digits in Test Data to Determine Conformance with Specifications.
imply the same absolute limit of exactly two and a half inches
and for purposes of determining conformance with
6. Rounding Method
specifications, an observed value or a calculated value is to be
6.1 Where Applicable—Theroundingmethodapplieswhere
compareddirectlywiththespecifiedlimit.Thus,anydeviation,
it is the intent that a limited number of digits in an observed
howeversmall,outsidethespecificationlimitsignifiesnoncon-
value or a calculated value are to be considered significant for
formancewiththespecifications.Thiswillbereferredtoasthe
purposes of determining conformance with specifications.
absolute method, which is discussed in Section 5.
4.1.3 Rounding Method—Inotherfields,specificationlimits 6.2 How Applied—With the rounding method, an observed
of 2.5 in. max, 2.50 in. max, 2.500 in. max are taken to imply valueoracalculatedvalueshouldberoundedbytheprocedure
that, for the purposes of determining conformance with prescribedin4.1.3tothenearestunitinthedesignatedplaceof
specifications, an observed value or a calculated value should figures stated in the standard, as, for example, “to the nearest
be rounded to the nearest 0.1 in., 0.01 in., 0.001 in., kPa,” “to the nearest 10 ohms,” “to the nearest 0.1 percent,”
respectively, and then compared with the specification limit. etc. The rounded value should then be compared with the
This will be referred to as the rounding method, which is specified limit, and conformance or nonconformance with the
discussed in Section 6. specification based on this comparison.
E29−13 (2019)
6.3 How Expressed—This intent may be expressed in the 6.4 Rounding Procedure—The actual rounding procedure
standard in one of the following forms: shall be as follows:
6.3.1 If the rounding method is to apply to all specified 6.4.1 When the digit next beyond the last place to be
limits in the standard, and if all digits expressed in the retained is less than 5, retain unchanged the digit in the last
specification limit are to be considered significant, this may be place retained.
indicated by including the following statement in the standard: 6.4.2 When the digit next beyond the last place to be
retained is greater than 5, increase by 1 the digit in the last
The following applies to all specified limits in this standard: For purposes of
determining conformance with these specifications, an observed value or a
place retained.
calculated value shall be rounded “to the nearest unit” in the last right-hand digit
6.4.3 When the digit next beyond the last place to be
used in expressing the specification limit, in accordance with the rounding
retained is 5, and there are no digits beyond this 5, or only
method of ASTM Practice E29, for Using Significant Digits in Test Data to De-
termine Conformance with Specifications.
zeros, increase by 1 the digit in the last place retained if it is
6.3.2 Iftheroundingmethodistoapplyonlytothespecified odd, leave the digit unchanged if it is even. Increase by 1 the
digit in the last place retained, if there are non-zero digits
limits for certain selected requirements, this may be indicated
by including the following statement in the standard: beyond this 5.
The following applies to specified limits for requirements on (tensile
NOTE 1—This method for rounding 5’s is not universally used by
strength), (elongation), and ( . ) given in ., (applicable section number and
software packages.
title) and ( . ) of this standard: For purposes of determining conformance with
these specifications, an observed value or a calculated value shall be rounded
6.4.4 This rounding procedure may be restated simply as
to the nearest 1 kPa for (tensile strength), to the nearest (1 percent) for
follows: When rounding a number to one having a specified
(elongation), and to the nearest ( . ) for ( . ) in accordance with the rounding
number of significant digits, choose that which is nearest. If
method of ASTM Practice E29 Using Significant Digits in Test Data to Deter-
mine Conformance with Specifications.
two choices are possible, as when the digits dropped are
exactlya5ora5 followed only by zeros, choose that ending
6.3.3 If the rounding method is to apply to all specified
in an even digit. Table 1 gives examples of applying this
limits in a table, this may be indicated by a note in the manner
rounding procedure.
shown in the following examples:
6.3.3.1 Example 1—Same significant digits for all items:
6.5 The rounded value should be obtained in one step by
Chemical Composition,
direct rounding of the most precise value available and not in
% mass
two or more successive roundings. For example: 89490
rounded to the nearest 1000 is at once 89000; it would be
Copper 4.5 ± 0.5
Iron 1.0 max
incorrect to round first to the nearest 100, giving 89500 and
Silicon 2.5 ± 0.5
then to the nearest 1000, giving 90000.
Other constituents (magnesium + zinc + manganese) 0.5 max
Aluminum remainder
6.6 Special Case, Rounding to the Nearest 50, 5, 0.5, 0.05,
For purposes of determining conformance with these specifications, an
etc.—If in special cases it is desired to specify rounding to the
observed value or a calculated value shall be rounded to the nearest 0.1
nearest 50, 5, 0.5, 0.05, etc., this may be done by so indicating
percent, in accordance with the rounding method of ASTM Practice E29 Using
Significant Digits in Test Data to Determine Conformance with Specifications.
6.3.3.2 Example 2—Significant digits not the same for all
items; similar requirements:
The rounding procedure given in this practice is the same as the one given in
the ASTM Manual 7 on Presentation of Data and Control Chart Analysis.
Chemical Composition, % mass
min max
A
TABLE 1 Examples of Rounding
Nickel 57 .
Rounded
Chromium 14 18
Observed Valuetobe Conforms
Manganese . 3
To Be
Value or Used for with
Silicon . 0.40
Specified Limit Rounded
Calculated Purposes of Specified
Carbon . 0.25
to Nearest
Value Determining Limit
...

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: E29 − 13 E29 − 13 (Reapproved 2019) An American National Standard
Standard Practice for
Using Significant Digits in Test Data to Determine
Conformance with Specifications
This standard is issued under the fixed designation E29; 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.
1. Scope*Scope
1.1 This practice is intended to assist the various technical committees in the use of uniform methods of indicating the number
of digits which are to be considered significant in specification limits, for example, specified maximum values and specified
minimum values. Its aim is to outline methods which should aid in clarifying the intended meaning of specification limits with
which observed values or calculated test results are compared in determining conformance with specifications.
1.2 This practice is intended to be used in determining conformance with specifications when the applicable ASTM
specifications or standards make direct reference to this practice.
1.3 Reference to this practice is valid only when a choice of method has been indicated, that is, either absolute method or
rounding method.
1.4 The system of units for this practice is not specified. Dimensional quantities in the practice are presented only as illustrations
of calculation methods. The examples are not binding on products or test methods treated.
1.5 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 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:
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E2282 Guide for Defining the Test Result of a Test Method
IEEE/ASTM SI 10 Standard for Use of the International System of Units (SI): The Modern Metric System
3. Terminology
3.1 Definitions—Terminology E456 provides a more extensive list of terms in E11 standards.
3.1.1 observed value, n—the value obtained by making an observation. E2282
3.1.2 repeatability conditions, n—conditions where independent test results are obtained with the same method on identical test
items in the same laboratory by the same operator using the same equipment within short intervals of time. E177
3.1.3 repeatability standard deviation (s ), n—the standard deviation of test results obtained under repeatability conditions.
r
E177
This practice is under the jurisdiction of ASTM Committee E11 on Quality and Statistics and is the direct responsibility of Subcommittee E11.30 on Statistical Quality
Control.
Current edition approved Aug. 1, 2013Jan. 1, 2019. Published August 2013January 2019. Originally approved in 1940. Last previous edition approved in 20082013 as
E29 – 08.E29 – 13. DOI: 10.1520/E0029-13.10.1520/E0029-13R19.
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’sstandard’s Document Summary page on the ASTM website.
*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
E29 − 13 (2019)
3.1.4 significant digit—any of the figures 0 through 9 that is used with its place value to denote a numerical quantity to some
desired approximation, excepting all leading zeros and some trailing zeros in numbers not represented with a decimal point.
3.1.4.1 Discussion—
This definition of significant digits relates to how the number is represented as a decimal. It should not be inferred that a
measurement value is precise to the number of significant digits used to represent it.
3.1.4.2 Discussion—
The digit zero may either indicate a specific value or indicate place only. Zeros leading the first nonzero digit of a number indicate
order of magnitude only and are not significant digits. For example, the number 0.0034 has two significant digits. Zeros trailing
the last nonzero digit for numbers represented with a decimal point are significant digits. For example, the numbers 1270. and
32.00 each have four significant digits. The significance of trailing zeros for numbers represented without use of a decimal point
can only be identified from knowledge of the source of the value. For example, a modulus strength, stated as 140 000 Pa, may have
as few as two or as many as six significant digits.
3.1.4.3 Discussion—
To eliminate ambiguity, the exponential notation may be used. Thus, 1.40 × 10 indicates that the modulus is reported to the nearest
0.01 × 10 or 1000 Pa.
3.1.4.4 Discussion—
Use of appropriate SI prefixes is recommended for metric units to reduce the need for trailing zeros of uncertain significance. Thus,
140 kPa (without the decimal point) indicates that the modulus is reported either to the nearest 10 or 1 kPa, which is ambiguous
with respect to the number of significant digits. However, 0.140 MPa clearly indicates that the modulus is reported to the nearest
1 kPa, and 0.14 MPa clearly indicates that the modulus is reported to the nearest 10 kPa.
3.1.5 test result, n—the value of a characteristic obtained by carrying out a specified test method. E2282
4. Significance and Use
4.1 This practice describes two commonly accepted methods of rounding data, identified as the Absolute Method and the
Rounding Method. In the applications of this practice to a specific material or materials it is essential to specify which method is
intended to apply. In the absence of such specification, reference to this practice, which expresses no preference as to which method
should apply, would be meaningless. The choice of method depends upon the current practice of the particular branch of industry
or technology concerned, and should therefore be specified in the prime publication.
4.1.1 The unqualified statement of a numerical limit, such as “2.50 in. max,” cannot, in view of different established practices
and customs, be regarded as carrying a definite operational meaning concerning the number of digits to be retained in an observed
or a calculated value for purposes of determining conformance with specifications.
4.1.2 Absolute Method—In some fields, specification limits of 2.5 in. max, 2.50 in. max, and 2.500 in. max are all taken to imply
the same absolute limit of exactly two and a half inches and for purposes of determining conformance with specifications, an
observed value or a calculated value is to be compared directly with the specified limit. Thus, any deviation, however small, outside
the specification limit signifies nonconformance with the specifications. This will be referred to as the absolute method, which is
discussed in Section 5.
4.1.3 Rounding Method—In other fields, specification limits of 2.5 in. max, 2.50 in. max, 2.500 in. max are taken to imply that,
for the purposes of determining conformance with specifications, an observed value or a calculated value should be rounded to the
nearest 0.1 in., 0.01 in., 0.001 in., respectively, and then compared with the specification limit. This will be referred to as the
rounding method, which is discussed in Section 6.
4.2 Section 7 of this practice gives guidelines for use in recording, calculating, and reporting the final result for test data.
5. Absolute Method
5.1 Where Applicable—The absolute method applies where it is the intent that all digits in an observed value or a calculated
value are to be considered significant for purposes of determining conformance with specifications. Under these conditions, the
specified limits are referred to as absolute limits.
5.2 How Applied—With the absolute method, an observed value or a calculated value is not to be rounded, but is to be compared
directly with the specified limiting value. Conformance or nonconformance with the specification is based on this comparison.
E29 − 13 (2019)
5.3 How Expressed—This intent may be expressed in the standard in one of the following forms:
5.3.1 If the absolute method is to apply to all specified limits in the standard, this may be indicated by including the following
sentence in the standard:
For purposes of determining conformance with these specification, all
specified limits in this standard are absolute limits, as defined in ASTM Practice
E29, for Using Significant Digits in Test Data to Determine Conformance with
Specifications.
For purposes of determining conformance with these specifications, all
specified limits in this standard are absolute limits, as defined in ASTM Practice
E29, for Using Significant Digits in Test Data to Determine Conformance with
Specifications.
5.3.2 If the absolute method is to apply to all specified limits of some general type in the standard (such as dimensional tolerance
limits), this may be indicated by including the following sentence in the standard:
For purposes of determining conformance with these specifications, all
specified (dimensional tolerance) limits are absolute limits, as defined in ASTM
Practice E29, for Using Significant Digits in Test Data to Determine Confor-
mance with Specifications.
5.3.3 If the absolute method is to apply to all specified limits given in a table, this may be indicated by including a footnote
with the table as follows:
If the absolute method is to apply to all specified limits given in a table, this may be indicated by including a footnote with the
table as follows:
A
Capacity
Volumetric Tolerance
mL ± mL
10 0.02
25 0.03
50 0.05
100 0.10
A
Tolerance limits specified are absolute limits as defined in Practice E29, for Using Significant Digits in Test Data to Determine Conformance with Specifications.
6. Rounding Method
6.1 Where Applicable—The rounding method applies where it is the intent that a limited number of digits in an observed value
or a calculated value are to be considered significant for purposes of determining conformance with specifications.
6.2 How Applied—With the rounding method, an observed value or a calculated value should be rounded by the procedure
prescribed in 4.1.3 to the nearest unit in the designated place of figures stated in the standard, as, for example, “to the nearest kPa,”
“to the nearest 10 ohms,” “to the nearest 0.1 percent,” etc. The rounded value should then be compared with the specified limit,
and conformance or nonconformance with the specification based on this comparison.
6.3 How Expressed—This intent may be expressed in the standard in one of the following forms:
6.3.1 If the rounding method is to apply to all specified limits in the standard, and if all digits expressed in the specification limit
are to be considered significant, this may be indicated by including the following statement in the standard:
The following applies to all specified limits in this standard: For purposes of
determining conformance with these specifications, an observed value or a
calculated value shall be rounded “to the nearest unit” in the last right-hand digit
used in expressing the specification limit, in accordance with the rounding
method of ASTM Practice E29, for Using Significant Digits in Test Data to Deter-
mine Conformance with Specifications.
6.3.2 If the rounding method is to apply only to the specified limits for certain selected requirements, this may be indicated by
including the following statement in the standard:
The following applies to specified limits for requirements on (tensile
strength), (elongation), and ( . ) given in ., (applicable section number and
title) and ( . ) of this standard: For purposes of determining conformance with
these specifications, an observed value or a calculated value shall be rounded
to the nearest 1kPa for (tensile strength), to the nearest (1 percent) for
(elongation), and to the nearest ( . ) for ( . ) in accordance with the rounding
method of ASTM Practice E29 Using Significant Digits in Test Data to Deter-
mine Conformance with Specifications.
The following applies to specified limits for requirements on (tensile
strength), (elongation), and ( . ) given in ., (applicable section number and
title) and ( . ) of this standard: For purposes of determining conformance with
these specifications, an observed value or a calculated value shall be rounded
to the nearest 1 kPa for (tensile strength), to the nearest (1 percent) for
(elongation), and to the nearest ( . ) for ( . ) in accordance with the rounding
method of ASTM Practice E29 Using Significant Digits in Test Data to Deter-
mine Conformance with Specifications.
E29 − 13 (2019)
6.3.3 If the rounding method is to apply to all specified limits in a table, this may be indicated by a note in the manner shown
in the following examples:
6.3.3.1 Example 1—Same significant digits for all items:
Same significant digits for all items:
Chemical Composition,
% mass
Copper 4.5 ± 0.5
Iron 1.0 max
Silicon 2.5 ± 0.5
Other constituents (magnesium + zinc + manganese) 0.5 max
Aluminum remainder
For purposes of determining conformance with these specifications, an
observed value or a calculated value shall be rounded to the nearest 0.1
percent, in accordance with the rounding method of ASTM Practice E29 Using
Significant Digits in Test Data to Determine Conformance with Specifications.
6.3.3.2 Example 2—Significant digits not the same for all items; similar requirements:
Significant digits not the same for all items; similar requirements:
Chemical Composition, % mass
min max
Nickel 57 .
Chromium 14 18
Manganese . 3
Silicon . 0.40
Carbon . 0.25
Sulfur . 0.03
Iron remainder
For purposes of determining conformance with these specifications, an
observed value or a calculated value shal
...