ASTM B188-15(2023)

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.
Designation: B188 − 15 (Reapproved 2023)
Standard Specification for
Seamless Copper Bus Pipe and Tube
This standard is issued under the fixed designation B188; 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 2. Referenced Documents
1.1 This specification establishes the requirements for seam- 2.1 ASTM Standards:
less copper bus pipe and tube intended for use as electrical B193 Test Method for Resistivity of Electrical Conductor
conductors. Materials
1.1.1 The product shall be made from one of the following B428 Test Method for Angle of Twist in Rectangular and
coppers, as denoted in the ordering information: Square Copper and Copper Alloy Tube
B577 Test Methods for Detection of Cuprous Oxide (Hydro-
Previously
Copper
Used Type of Copper
gen Embrittlement Susceptibility) in Copper
UNS No.
Designation
B601 Classification for Temper Designations for Copper and
Copper Alloys—Wrought and Cast
C10100 OFE Oxygen-free, electronic
C10200 OF Oxygen-free without residual deoxidants
B846 Terminology for Copper and Copper Alloys
C10300 — Oxygen-free, extra low phosphorus
E8/E8M Test Methods for Tension Testing of Metallic Ma-
C10400, C10500, OFS Oxygen-free, silver bearing
terials
C10700
C11000 ETP Electrolytic tough pitch
E18 Test Methods for Rockwell Hardness of Metallic Ma-
C11300, C11400, STP Silver-bearing tough pitch
terials
C11600
E29 Practice for Using Significant Digits in Test Data to
C12000 DLP Phosphorized, low residual phosphorus
Determine Conformance with Specifications
1.2 Unless otherwise specified, any one of the above cop-
E53 Test Method for Determination of Copper in Unalloyed
pers may be furnished.
Copper by Gravimetry (Withdrawn 2022)
1.3 Units—The values stated in inch-pound units are to be
E62 Test Methods for Chemical Analysis of Copper and
regarded as standard. The values given in parentheses are 4
Copper Alloys (Photometric Methods) (Withdrawn 2010)
mathematical conversions to SI units, which are provided for
E243 Practice for Electromagnetic (Eddy Current) Examina-
information only and are not considered standard.
tion of Copper and Copper-Alloy Tubes
1.4 This international standard was developed in accor-
E255 Practice for Sampling Copper and Copper Alloys for
dance with internationally recognized principles on standard-
the Determination of Chemical Composition
ization established in the Decision on Principles for the
E527 Practice for Numbering Metals and Alloys in the
Development of International Standards, Guides and Recom-
Unified Numbering System (UNS)
mendations issued by the World Trade Organization Technical
3. Terminology
Barriers to Trade (TBT) Committee.
3.1 For definitions of terms related to copper and copper
alloys, refer to Terminology B846.
This specification is under the jurisdiction of ASTM Committee B05 on Copper
and Copper Alloys and is the direct responsibility of Subcommittee B05.04 on Pipe 3.2 Definitions of Terms Specific to This Standard:
and Tube.
Current edition approved Oct. 1, 2023. Published October 2023. Originally
ε1 3
approved in 1944. Last previous edition approved in 2015 as B188 – 15 . DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/B0188-15R23. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The UNS system for copper and copper alloys (see Practice E527) is a simple Standards volume information, refer to the standard’s Document Summary page on
expansion of the former standard designation system accomplished by the addition the ASTM website.
of a prefix “C” and a suffix “00.” The suffix can be used to accommodate The last approved version of this historical standard is referenced on
composition variations of the base alloy. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B188 − 15 (2023)
3.2.1 bus pipe or tube—a high conductivity copper tubular 5. Materials and Manufacture
product used as an electrical conductor.
5.1 Material:
4. Ordering Information 5.1.1 The material of manufacture shall be cast billet of one
of the UNS copper alloy numbers included in the scope, and as
4.1 Include the following specified choices when placing
so specified in the contract or purchase order, and shall be of
orders for product under this specification, as applicable:
such purity and soundness as to be suitable for processing into
4.1.1 ASTM designation and year of issue,
lengths of pipe or tube for the intended application.
4.1.2 Copper UNS designation (1.1.1 and 1.2),
4.1.3 Temper (Section 7),
5.2 Manufacture:
4.1.4 Dimensions and form (Section 12),
5.2.1 The product shall be manufactured by such hot-
4.1.5 Length (Section 12),
working, cold-working, and annealing processes as to produce
4.1.6 Quantity–total weight or total length or number of
a uniform, wrought, seamless structure in the finished product.
pieces of each size (Table 1),
5.2.2 The method of manufacture shall be hot or cold
4.2 The following options are available but may not be
working to the finished size, and subsequent annealing when
included unless specified at the time of placing the order when
required to meet the temper properties specified (see 7.1).
required:
4.2.1 Bend test (Section 10),
6. Chemical Composition
4.2.2 Hydrogen embrittlement susceptibility test (Section
10),
6.1 The material shall conform to the chemical composition
4.2.3 Microscopical examination (Section 10),
requirements in Table 2 for the copper UNS No. designation
4.2.4 Tension testing (Section 9),
specified in the ordering information.
4.2.5 Eddy-current test (Section 11),
6.2 These composition limits do not preclude the presence
4.2.6 Certification (Section 21),
of other elements. By agreement between the manufacturer or
4.2.7 Test report (Section 22), and
supplier and purchaser, limits may be established and analysis
4.2.8 If the specification number is required to be shown on
the packaging (23.2). required for unnamed elements.
A
TABLE 1 Dimensions and Weights of Copper Pipe, Nominal or Standard Pipe Sizes
Dimensions, in. (mm)
Nominal or Standard Cross-Sectional Area of Theoretical Weight, lb/ft
2 2
Pipe Size, in. Wall, in. (mm ) (kg/m)
Outside Diameter Inside Diameter Wall Thickness
Regular
⁄4 0.540(13.7) 0.376(9.55) 0.082(2.08) 0.118(0.761) 0.457(0.680)
⁄8 0.675(17.1) 0.495(12.6) 0.090(2.29) 0.165(1.06) 0.641(0.954)
⁄2 0.840(21.3) 0.626(15.9) 0.107(2.72) 0.246(1.59) 0.955(1.42)
⁄4 1.050(26.7) 0.822(20.9) 0.114(2.90) 0.335(2.16) 1.30(1.93)
1 1.315(33.4) 1.063(27.0) 0.126(3.20) 0.471(3.04) 1.82(2.71)
1 ⁄4 1.660(42.2) 1.368(34.7) 0.146(3.71) 0.694(4.48) 2.69(4.00)
1 ⁄2 1.900(48.3) 1.600(40.6) 0.150(3.81) 0.825(5.32) 3.20(4.76)
2 2.375(60.3) 2.063(52.4) 0.156(3.96) 1.09(7.03) 4.22(6.28)
2 ⁄2 2.875(73.0) 2.501(63.5) 0.187(4.75) 1.58(10.2) 6.12(9.11)
3 3.500(88.9) 3.062(77.8) 0.219(5.56) 2.26(14.6) 8.75(13.0)
3 ⁄2 4.000 (102) 3.500(88.9) 0.250(6.35) 2.95(19.0) 11.4(17.0)
4 4.500 (114) 4.000 (102) 0.250(6.35) 3.34(21.5) 12.9(19.2)
5 5.562 (141) 5.062 (129) 0.250(6.35) 4.17(26.9) 16.2(24.1)
6 6.625 (168) 6.125 (156) 0.250(6.35) 5.01(32.3) 19.4(28.9)
8 8.625 (219) 8.001 (203) 0.312(7.92) 8.15(52.6) 31.6(47.0)
10 10.750 (273) 10.020 (255) 0.365(9.27) 11.9(76.8) 46.2(68.7)
12 12.750 (324) 12.000 (305) 0.375(9.52) 14.6(94.2) 56.5(84.1)
Extra Strong
⁄4 0.540(13.7) 0.294(7.47) 0.123(3.12) 0.161(1.04) 0.625(0.930)
⁄8 0.675(17.1) 0.421(10.7) 0.127(3.23) 0.219(1.41) 0.847(1.26)
⁄2 0.840(21.3) 0.542(13.8) 0.149(3.78) 0.323(2.08) 1.25(1.86)
⁄4 1.050(26.7) 0.736(18.7) 0.157(3.99) 0.440(2.84) 1.71(2.54)
1 1.315(33.4) 0.951(24.2) 0.182(4.62) 0.648(4.18) 2.51(3.73)
1 ⁄4 1.660(42.2) 1.272(32.3) 0.194(4.93) 0.893(5.76) 3.46(5.15)
1 ⁄2 1.900(48.3) 1.494(37.9) 0.203(5.16) 1.08(6.97) 4.19(6.23)
2 2.375(60.3) 1.933(49.1) 0.221(5.61) 1.50(9.68) 5.80(8.63)
2 ⁄2 2.875(73.0) 2.315(58.8) 0.280(7.11) 2.28(14.7) 8.85(13.2)
3 3.500(88.9) 2.892(73.6) 0.304(7.72) 3.05(19.7) 11.8(17.6)
3 ⁄2 4.000 (102) 3.358(85.3) 0.321(8.15) 3.71(23.9) 14.4(21.4)
4 4.500 (114) 3.818(97.0) 0.341(8.66) 4.46(28.8) 17.3(25.7)
5 5.562 (141) 4.812 (122) 0.375(9.52) 6.11(39.4) 23.7(35.3)
6 6.625 (168) 5.751 (146) 0.437(11.1) 8.50(54.8) 32.9(49.0)
8 8.625 (219) 7.625 (194) 0.500(12.7) 12.8(82.6) 49.5(73.7)
10 10.750 (273) 9.750 (248) 0.500(12.7) 16.1(104) 62.4(92.9)
A 2
1 in. = 1 270 000 cmil.
B188 − 15 (2023)
TABLE 2 Chemical Requirements
NOTE 1—If the type of silver-bearing copper is not specified (that is, whether tough-pitch, phosphorized, or oxygen-free) any one of the three types
may be supplied at the option of the manufacturer.
Composition, %
Element Copper UNS No.
A B B B C C C
C10100 C10200 C10300 C10400 C10500 C10700 C11000 C11300 C11400 C11600 C12000
D E
Copper (incl silver), min 99.99 99.95 99.95 99.95 99.95 99.95 99.90 99.90 99.90 99.90 99.90
A
Phosphorus . 0.001– . . . . . . . 0.004–
0.005 0.012
Oxygen, max. 0.0005 0.0010 . 0.0010 0.0010 0.0010 . . . . .
A F F F F F F
Silver . . 8 10 25 . 8 10 25 .
A
Impurity maximums in ppm of C10100 shall be: antimony 4, arsenic 5, bismuth 1.0, cadmium 1, iron 10, lead 5, manganese 0.5, nickel 10, phosphorus 3, selenium 3,
silver 25, sulfur 15, tellurium 2, tin 2, and zinc 1.
B
C10400, C01500, and C10700 are oxygen-free coppers with the addition of a specified amount of silver. The compositions of these alloys are equivalent to C10200 plus
the intentional addition of silver.
C
C11300, C11400, C11500, and C11600 are electrolytic tough-pitch copper with silver additions. The compositions of these alloys are equivalent to C11000 plus the
intentional addition of silver.
D
Copper shall be determined by difference between “impurity total” and 100 %.
E
Copper (includes silver) + phosphorus, min.
F
Values are minimum silver in troy ounces per avoirdupois ton (1 oz/ton is equivalent to 0.0034 %).
7. Temper 9. Mechanical Property Requirements
7.1 The standard tempers for products described in this
9.1 Product furnished under this specification shall conform
specification are given in Table 3 as defined in Classification
to the tensile and hardness property requirements prescribed in
B601.
Table 3.
7.1.1 Soft Anneal—O60.
9.1.1 Tension testing for tensile and elongation information
7.1.2 Hard Drawn—H80.
need not be performed except when specified by the purchaser
at the time of placing the order (see 4.2.4).
8. Electrical Resistivity Requirements
9.1.2 The tension test shall be used to resolve cases of
8.1 The product furnished shall conform to the maximum
dispute.
electrical resistivity requirements prescribed in Table 3 when
tested in accordance with Test Method B193.
A
TABLE 3 Mechanical and Electrical Properties
B
Electrical Resistivity max at 20°C (68°F),
Tensile Strength
Ω·g/m
Temper Designation
B
ksi (MPa)
Copper UNS No.
C10200,
Rockwell
C10400,
Elongation Bend Test Hardness (F
C10500,
Classification and Size in 2 in. (51 Angle of Scale) 60-kg
C10700, 1
mm), min, % Bend,° Load ⁄16-in.
Code Name min max C10100 C11000, C10300 C12000
Ball
C11300,
C11400,
and
C11600
O60 Soft All types, all sizes . 37 (255) 25 180 0.15176 0.15328 0.15614 0.17031 50 max
Anneal
H80 Hard Rectangular or square:
Drawn
up to 6-in. (152-mm) major out- 35 (240) . 8 . 0.15585 0.15737 0.15940 0.17418 75 min
side dimension, incl up to ⁄16-
in. (4.8-mm) wall thickness,
incl
over ⁄16 -in. (4.8-mm) wall thick- 33 (230) . 15 . 0.15521 0.15673 0.15940 0.17418 65 min
ness
over 6-in. (152-mm) major out- 32 (220) . 20 . 0.15425 0.15577 0.15940 0.17418 65 min
side dimension
Round (pipe and tube):
up to 4-in. (102-mm) 40 (275) . 3 90 0.15713 0.15865 0.15940 0.17418 80 min
outside diameter, incl
over 4-in. (102-mm) outside diam- 38 (260) . 6 . 0.15585 0.15737 0.15940 0.17418 75 min
eter
A
See 6.1.
B
See Appendix X2.
B188 − 15 (2023)
10. Performance Requirements the product are still within prescribed limits and the product is
suitable for its intended application.
10.1 Bend Test Requirements:
10.1.1 The product shall conform to the bend testing re-
12. Dimensions, Weights, and Permissible Variations
quirements prescribed in Table 3.
12.1 General—For the purpose of determining conformance
10.1.2 Bend testing need not be performed except when
with the dimensional requirements given in this specification,
specified by the purchaser at the time of placing the order (see
any measured value outside the specified limiting values for
4.2.1).
any dimension may be cause for rejection.
10.2 Microscopical Examination:
12.2 Dimensions and Weights—The dimensions and
10.2.1 The test specimens of material designated as Copper
weights for nominal or standard copper pipe of various outside
UNS Nos. C10100, C10200, C10300, C10400, C10500,
diameters shall be as prescribed in Table 1.
C10700, and C12000 shall be free of cuprous oxide as
12.3 Weight Tolerances—The weight of the nominal or
determined by Procedure A of Test Methods B577. In case of
standard pipe shall not vary from the theoretical weight per
a dispute, a referee method in accordance with Procedure C
foot prescribed in Table 1 by more than the following:
shall be used.
Nominal or Standard Pipe Size, in. Weight Tolerance, %
10.2.2 The test need not be performed except when speci-
fied at the time of placing the order (see 4.2.3).
6 and under 5
Over 6 to 8, incl 7
10.3 Hydrogen Embrittlement Susceptibility Test:
Over 8 8
10.3.1 When tested, material designated as Copper UNS
12.4 Thickness Tolerances—The wall thickness of nominal
Nos. C10100, C10200, C10300, C10400, C10500, C10700,
or standard pipe at any point shall not be less than that
and C12000 shall pass the embrittlement test of Procedure B of
prescribed in Table 1 by more than the following:
Test Methods B577. The actual performance of this test is not
A
Nominal or Standard Pipe Size, in. Thickness Tolerance, %
mandatory under the terms of this specification unless specified
in the ordering information (see 4.2.2). In case of dispute, a
6 and under 5
Over 6 to 8, incl. 7
referee method in accordance with Procedure C of Test
Over 8 8
Methods B577 shall be employed.
A
Expressed to the nearest 0.001 in. (0.025 mm).
11. Other Requirements
12.5 Copper Tube (Other than Pipe):
11.1 Nondestructive Testing:
12.5.1 Round Tube—Wall thickness tolerances shall be in
11.1.1 When specified (see 4.2.5), the product shall be
accordance with Table 4. Diameter tolerances shall be in
tested in the final size but may be tested before the final anneal
accordance with Table 5.
or heat treatment, when these thermal treatments are required,
12.5.2 Rectangular Including Square Tube—Wall thickness
unless otherwise agreed upon by the manufacturer or supplier
tolerances shall be in accordance with Table 6. The tolerances
and purchaser.
on distance between parallel surfaces for rectangular and
11.1.2 Eddy-Current Test—When specified, each piece of
square tube in straight lengths only shall be in accordance with
1 1
product from ⁄8 in. (3.2 mm) up to and including 3 ⁄8 in.
Table 7 and Fig. 1.
(79.4 mm) nominal outside diameter, or 2 ⁄2 in. (63.5 mm)
12.5.3 Length and Length Tolerances—Tube ordered to
distance between outside parallel surfaces, shall be subjected to
specific or stock lengths with or without ends shall conform to
an eddy-current test. Testing shall follow the procedures of
the tolerances prescribed in Table 8 and Table 9.
Practice E243 except for determination of “end effect.” The
12.5.3.1 Pipe ordered to specific stock lengths with or
product shall be passed through an eddy-current testing unit
without ends shall conform to tolerances prescribed in Table 10
adjusted to provide information on the suitability of the product
and Table 11.
for the intended application.
12.6 Roundness—For tube or pipe of H (drawn) tempers in
11.1.3 Notch-depth standards rounded to the nearest
straight lengths, the roundness tolerances shall be as follows:
0.001 in. (0.025 mm) shall be 22 % of the nominal wall
t/D (Ratio of Wall
thickness. The notch depth tolerance shall be 60.0005 in. Roundness Tolerance, % of Outside Diameter
Thickness to Outside
(Expressed to the Nearest 0.001 in. (0.025 mm))
(0.013 mm). Alternatively, when the test is performed using
Diameter)
speed-insensitive equipment that can select a maximum imbal-
0.01 to 0.03 incl 1.5
ance signal, a maximum imbalance signal of 0.3 % shall be
Over 0.03 to 0.05, incl 1.0
used.
Over 0.05 to 0.10, incl 0.8 or 0.002 in. (0.51 mm), whichever is greater
Over 0.10 0.7 or 0.002 in. (0.51 mm), whichever is greater
11.1.4 Product that does not actuate the signaling device of
the eddy-current test shall be considered as conforming to the 12.6.1 Compliance with the roundness tolerance shall be
requirements of this test. Product with discontinuities indicated determined by taking measurements on the outside diameter
by the testing unit may be reexamined or retested, at the option only, irrespective of the manner in which the tube dimensions
of the manufacturer, to determine whether the discontinuity is are specified.
cause for rejection. Signals that are found to have been caused 12.6.2 The deviation from roundness is measured as the
by minor mechanical damage, soil, or moisture shall not be difference between major and minor diameters as determined at
cause for rejection of the product provided the dimensions of any one cross section of the tube.
B188 − 15 (2023)
TABLE 4 Wall Thickness Tolerances for Copper Tube (Not Applicable to Pipe)
NOTE 1—Maximum Deviation at Any Point: The following tolerances are plus and minus; if tolerances all plus or all minus are desired, double the
values given.
Outside Diameter, in. (mm)
1 5
Over ⁄8 (3.15) Over ⁄8 (15.9) Over 1 (25.4) Over 2 (50.8) Over 4 (102) Over 7 (178)
Wall Thickness, in. (mm)
to ⁄8 (15.9), to 1 (25.4), to 2 (50.8), to 4 (102), to 7 (178), to 10 (254),
incl incl incl incl incl incl
Up to 0.017 (0.432) incl 0.001 (0.025) 0.0015 (0.038) 0.002 (0.051) . . .
Over 0.017 (0.432) to 0.024 (0.610) incl 0.002 (0.051) 0.002 (0.051) 0.0025 (0.064) . . .
Over 0.024 (0.610) to 0.034 (0.864) incl 0.0025 (0.064) 0.0025 (0.064) 0.003 (0.076) 0.004 (0.10) . .
Over 0.034 (0.864) to 0.057 (1.45) incl 0.003 (0.076) 0.0035 (0.089) 0.0035 (0.089) 0.005 (0.13) 0.007 (0.18)
Over 0.057 (1.45) to 0.082 (2.08) incl 0.0035 (0.089) 0.004 (0.10) 0.004 (0.10) 0.006 (0.15) 0.008 (0.20) 0.010 (0.25)
Over 0.082 (2.08) to 0.119 (3.02) incl 0.004 (0.10) 0.005 (0.13) 0.005 (0.13) 0.007 (0.18) 0.009 (0.23) 0.011 (0.28)
Over 0.119 (3.02) to 0.164 (4.17) incl 0.005 (0.13) 0.006 (0.15) 0.006 (0.15) 0.008 (0.20) 0.010 (0.25) 0.012 (0.30)
Over 0.164 (4.17) to 0.219 (5.56) incl 0.007 (0.18) 0.0075 (0.19) 0.008 (0.20) 0.010 (0.25) 0.012 (0.30) 0.014 (0.36)
Over 0.219 (5.56) to 0.283 (7.19) incl . 0.009 (0.23) 0.010 (0.25) 0.012 (0.30) 0.014 (0.36) 0.016 (0.41)
A A A A
Over 0.283 (7.19) to 0.379 (9.63) incl . 0.012 (0.30) 5 5 6 6
A A A A
Over 0.379 (9.62) . . 5 5 6 6
A
Percent of the specified wall expressed to nearest 0.001 in. (0.025 mm).
TABLE 5 Average Diameter Tolerances for Copper Tube
12.8.1 Round Tubes—For round tubes of any drawn temper,
1 1
Tolerance, ⁄4 in. to 3 ⁄2 in. (6.35 mm to 88.9 mm) in outside diameter,
Diameter to Which
Specified Diameter, in. (mm) plus and minus,
A
inclusive, the straightness tolerances shall be in accordance
Tolerance Applies
in. (mm)
with Table 12.
Up to ⁄8 (15.9), incl inside or outside 0.002 (0.051)
12.8.2 Rectangular and Square Tubes—For rectangular and
Over ⁄8 (15.9) to 1 (25.4), incl inside or outside 0.0025 (0.064)
Over 1 (25.4) to 2 (50.8), incl inside or outside 0.003 (0.076)
square tubes of any drawn temper, the straightness tolerance
Over 2 (50.8) to 3 (76.2), incl inside or outside 0.004 (0.10)
shall be ⁄2 in. (13 mm) maximum curvature (depth of arc) in
Over 3 (76.2) to 4 (102), incl inside or outside 0.005 (0.13)
any 6 ft (1.8 m) portion of the total length.
Over 4 (102) to 5 (127), incl inside or outside 0.006 (0.15)
Over 5 (127) to 6 (152), incl inside or outside 0.007 (0.18)
12.9 Unit Weight—For purpose of calculating weights, cross
Over 6 (152) to 8 (203), incl inside or outside 0.008 (0.20)
sections, and so forth, the density of the copper shall be taken
Over 8 (203) to 10 (254), incl inside or outside 0.010 (0.25)
3 3
A as 0.323 lb/in. (8.94 g/cm ).
The average outside diameter of a tube is the average of the maximum and
minimum outside diameters, as determined at any one cross-section of the tube.
12.10 Corner Radius: Rectangular and Square Tubes—The
permissible radii for commercially square corners shall be in
accordance with Table 13.
12.6.3 No tolerances have been established for as-extruded
12.11 Twist Tolerances: Rectangular and Square Tubes—
tube, redrawn tube, annealed tube, any tube furnished in coils,
The maximum twist about the longitudinal axis of drawn
or drawn tube whose wall thickness is under 0.016 in.
temper rectangular and square tubes shall not exceed 1°/ft
(0.406 mm).
(1°/305 mm) of length, measured to the nearest degree, and the
total angle of twist shall not exceed 20° when measured in
12.7 Squareness of Cut—For pipe and tube in straight
accordance with Test Method B428. The requirement is not
lengths, the departure from squareness of the end of any pipe
applicable to tubes in the annealed temper or to tubes whose
or tube shall not exceed the following:
specified major dimension is less than ⁄2 in. (12.7 mm).
12.7.1 Pipe:
Specified Outside
Tolerance 13. Workmanship, Finish, and Appearance
Diameter, in. (mm)
13.1 The product shall be free of defects of a nature that
Up to ⁄8 (15.9), incl 0.010 in. (0.25 mm)
would interfere with the intended application. It shall be well
Over ⁄8 (15.9) 0.016 in./in. (0.016 mm/mm) of diameter
cleaned and free from dirt.
12.7.2 Round Tube:
Specified Outside
14. Sampling
Tolerance
Diameter, in. (mm)
14.1 The lot size, portion size, and sample size of the
Up to ⁄8 (15.9), incl 0.010 in. (0.25 mm)
finished product shall be as follows:
Over ⁄8 (15.9) 0.016 in./in. (0.016 mm/mm) of diameter
...