ASTM A787/A787M-22

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: A787/A787M − 20a A787/A787M − 22
Standard Specification for
Electric-Resistance-Welded Metallic-Coated Carbon Steel
Mechanical Tubing
This standard is issued under the fixed designation A787/A787M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This specification covers round, square, rectangular, and special shape, electric-resistance-welded carbon steel mechanical
tubing, either zinc-coated (galvanized) after welding or produced from aluminum-coated, zinc-coated (galvanized), zinc-iron
alloy-coated (galvannealed), 55 % aluminum-zinc alloy-coated, or zinc-aluminum-magnesium alloy-coated carbon steel sheet.
Tubing for use as electrical conduit (EMT) or intermediate metallic conduit (IMC) is not covered by this specification.
1.1.1 The product is available in various grades based on chemical requirements (Sections 5 and 9).
1.1.2 The product is available in various Types (Section 3).
1.2 This specification covers mechanical tubing with outside diameters or maximum outside dimensions ranging from ⁄2 to 15 in.
[12.7 to 380.0 mm] and wall thickness from 0.028 to 0.180 in. [0.70 to 4.60 mm]. Indeterminate wall thicknesses may be ordered.
In those cases the more stringent tolerances of Tables 3, 4, 5, 6, 12 and 13 shall apply.
1.3 When sizes within the ranges listed above are ordered, all other requirements of the specification shall be met.
1.4 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order specifies the
applicable M specification designation (SI units), the inch-pound units shall apply. The values stated in either SI units or
inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated
in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values
from the two systems may result in non-conformance with the standard.
1.5 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:
A463/A463M Specification for Steel Sheet, Aluminum-Coated, by the Hot-Dip Process
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.09
on Carbon Steel Tubular Products.
Current edition approved Nov. 1, 2020Nov. 1, 2022. Published November 2020November 2022. Originally approved in 1981. Last previous edition approved in 2020 as
A787/A787M – 20.A787/A787M – 20a. DOI: 10.1520/A0787_A0787M-20A.10.1520/A0787_A0787M-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
A787/A787M − 22
A653/A653M Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the
Hot-Dip Process
A792/A792M Specification for Steel Sheet, 55 % Aluminum-Zinc Alloy-Coated by the Hot-Dip Process
A924/A924M Specification for General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip Process
A1046/A1046M Specification for Steel Sheet, Zinc-Aluminum-Magnesium Alloy-Coated by the Hot-Dip Process
B6 Specification for Zinc
3. Classification
3.1 The types of tubing covered by this specification are:
Type Code Description
Number Letters
1 AWAC electric-resistance-welded aluminum-
coated carbon steel mechanical tubing
2 AWG electric-resistance-welded galvanized
carbon steel mechanical tubing
3 AWPG electric-resistance-welded carbon steel
mechanical tubing, post-hot dipped
galvanized
4 AWGA electric-resistance-welded carbon steel
mechanical tubing, zinc-iron alloy-
coated (galvannealed)
5 AWGZ electric-resistance-welded carbon steel
mechanical tubing, 55 % aluminum-zinc
alloy-coated
6 AWZAM electric-resistance-welded carbon steel
mechanical tubing, zinc-aluminum-
magnesium alloy-coated
4. Ordering Information
4.1 The ordered wall thickness of the tubing shall be the total of the base metal and the metallic coating.
4.2 Orders for material under this specification shall include the following:
4.2.1 Quantity (feet, metres, or number of lengths),
4.2.2 Type, code letters, and description (Sections 1 and 3),
4.2.3 ASTM specification designation number,
4.2.4 Coating designation and type of coating,
4.2.5 Chemically treated or not chemically treated raw material,
4.2.6 Oiled or dry (Section 16),
4.2.7 Extra smooth coating (if required),
4.2.8 Customer application, including fabrication,
4.2.9 Flash condition (7.1),
4.2.10 Steel chemical requirements of Type 1, 2, 4, 5 or 6, if applicable (Sections 5 and 9),
4.2.11 Report of chemical analysis if required (Sections 10 and 11),
4.2.12 Shape (round, square, rectangular, or special),
4.2.12.1 Dimensions: round—any two of the following: inside diameter, outside diameter, or wall thickness; square or
rectangular—outside dimension, wall thickness, and corner radii, if required. (See 12.1 and 13.1 and 13.2.)
A787/A787M − 22
4.2.13 Length: round tubing—mill lengths or definite cut lengths (see 12.2); square and rectangular tubing—mill cut lengths and
specified length (see 13.4).
4.2.14 Squareness of cut: round tubing, if required (see 12.3); square and rectangular tubing, if required (see 13.7),
4.2.15 Burrs removed, if required (see 15.2),
4.2.16 Special packaging (Section 19),
4.2.17 Customer specification number, if applicable,
4.2.18 Special requirements,
4.2.19 Special marking (Section 18), and
4.2.20 Recoating of outside diameter weld and heat-affected area, on precoated steel, if required.
5. Process
5.1 The steel shall be made from any process.
5.1.1 If a specific type of melting is required by the purchaser, it shall be stated on the purchase order.
5.1.2 The primary melting may incorporate separate degassing or refining and may be followed by secondary melting, using
electroslag remelting or vacuum remelting. If secondary melting is employed, the heat shall be defined as all of the ingots remelted
from a single primary heat.
5.1.3 Steel may be cast in ingots or may be strand cast. When steel of different grades is sequentially strand cast, identification
of the resultant transition material is required. The producer shall remove the transition material by an established procedure that
positively separates the grades.
5.2 For tubing produced from precoated steel sheet, the composition of the coating shall comply with the applicable specification.
5.2.1 Specification A463/A463M—Coating designation for aluminum coated-sheet.
5.2.2 Specification A653/A653M—Coating designation for galvanized and galvannealed steel sheet.
5.2.3 Specification A792/A792M—Coating designation for 55 % aluminum-zinc alloy-coated steel sheet.
5.2.4 Specification A1046/A1046M—Coating designation for zinc-aluminum-magnesium alloy-coated steel sheet.
5.2.5 Other grades of coated steel sheet, as listed in Table 1 and Table 2, may be used as the precoated material for the steel tubing
upon agreement between the manufacturer and the purchaser. Such steel sheet shall meet the requirements of Specification
A463/A463M, A653/A653M, A792/A792M, A924/A924M, and A1046/A1046M except for the chemical requirements.
6. Manufacture
6.1 Tubes shall be made by the electric-resistance welding process and shall be made from hot or cold-rolled precoated steel
except for Type 3.
6.1.1 The weld shall not be located within the radius of the corners of any shaped tube unless specified by the purchaser.
6.2 Special manufacturing practices allow for post-hot dipped galvanizing of welded tubing. If this product is desired all sections
of this specification will apply except Table 3. Wall thickness tolerances shall be determined by agreement between the producer
and purchaser.
A787/A787M − 22
A ,B
TABLE 1 Chemical Requirements for Low-Carbon Steels
Composition, %
Grade
Phos-
C Sulfur,
Designation
Carbon Manganese phorus,
max
max
MT1010 0.05 to 0.15 0.30 to 0.60 0.035 0.035
MT1015 0.10 to 0.20 0.30 to 0.60 0.035 0.035
MTX1015 0.10 to 0.20 0.60 to 0.90 0.035 0.035
MT1020 0.15 to 0.25 0.30 to 0.60 0.035 0.035
MTX1020 0.15 to 0.25 0.70 to 1.00 0.035 0.035
A
Rimmed or capped steels that may be used for the above grades are charac-
terized by a lack of uniformity in their chemical composition, and for this reason
product analysis is not technologically appropriate unless misapplication is clearly
indicated.
B
Chemistry represents heat analysis. Product analysis, except for rimmed or
capped steel, is to be in accordance with usual practice as shown in Table 7.
C
The letters MT indicate mechanical tubing.
A
TABLE 2 Chemical Requirements for Other Carbon Steels
Composition, %
Grade
Phos-
Designa-
Sulfur,
Carbon Manganese phorus,
tion
max
max
1008 0.10 max 0.50 0.035 0.035
1010 0.08 to 0.13 0.30 to 0.60 0.035 0.035
1015 0.12 to 0.18 0.30 to 0.60 0.035 0.035
1016 0.12 to 0.19 0.60 to 0.90 0.035 0.035
1017 0.14 to 0.21 0.30 to 0.60 0.035 0.035
1018 0.14 to 0.21 0.60 to 0.90 0.035 0.035
1019 0.14 to 0.21 0.70 to 1.00 0.035 0.035
1021 0.17 to 0.24 0.60 to 0.90 0.035 0.035
A
Chemistry represents heat analysis. Product analysis, except for rimmed or
capped steel, is to be in accordance with usual practice as shown in Table 7.
7. Flash Conditions
7.1 The flash conditions under which tubing may be furnished are as follows: The flash shall be removed from the outside
diameter of tubing covered by this specification. Tubing furnished to this specification may have the following conditions of
welding flash on the inside diameter.
7.1.1 Flash-In—All tubing in which the inside diameter welding flash does not exceed the wall thickness or ⁄32 in. [2.38 mm],
whichever is less.
7.1.2 Flash Controlled to 0.010 in. [0.25 mm], Maximum—Tubing in which the height of the remaining welding flash is controlled
so as not to exceed 0.010 in. [0.25 mm]. This condition is available in over 0.750 in. [19.0 mm] outside diameter and gauges
consistent with Tables 5 and 6.
7.1.3 Flash Controlled to 0.005 in. [0.13 mm], Maximum—When the inside diameter flash is controlled to 0.005 in. [0.13 mm]
maximum in tubing produced to outside diameter and wall thickness, inside diameter and wall thickness, or outside diameter and
inside diameter tolerances, the remaining inside diameter flash, if any, is part of the applicable inside diameter tolerance. This
controlled flash is available in 0.750 in. [19.0 mm] outside diameter or greater.
7.2 Tubes shall be furnished in the following shapes, as specified by the purchaser: round, square, rectangular, or special shapes
(as negotiated).
7.3 Recoating of the outside diameter weld-heat-affected area on precoated steel tubing may be performed at the manufacture’s
option, if not specifically requested by the purchaser.
A787/A787M − 22
A
TABLE 3 Wall Thickness Tolerance for Premetallic Coated As-Welded Tubing (inch-pound units)
Outside Diameter, in.
15 3 1
Over 1 to Over 1 ⁄16 to Over 3 ⁄4 to Over 4 ⁄2 to Over 6 to Over 8 to Over 10 to Over 12 to
Wall Thickness ⁄2 to 1, incl
15 3 1
1 ⁄16, incl 3 ⁄4, incl 4 ⁄2, incl 6, incl 8, incl 10, incl 12, incl 15, incl
Wall Thickness Tolerance, in., Plus and Minus
B
BWG in. Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus
22 0.028 0.002 0.006 0.002 0.006
20 0.035 0.003 0.006 0.002 0.006 0.002 0.006
18 0.049 0.004 0.007 0.003 0.008 0.003 0.008
16 0.065 0.005 0.007 0.004 0.008 0.003 0.009 0.003 0.009 0.002 0.010 0.002 0.010 0.002 0.010 0.002 0.010 0.002 0.010
14 0.083 0.006 0.008 0.006 0.008 0.005 0.009 0.005 0.009 0.004 0.010 0.004 0.010 0.003 0.011 0.003 0.011 0.003 0.011
13 0.095 0.008 0.010 0.008 0.010 0.007 0.011 0.007 0.011 0.006 0.012 0.006 0.012 0.004 0.014 0.004 0.014 0.004 0.014
12 0.109 0.008 0.010 0.008 0.010 0.007 0.011 0.007 0.011 0.006 0.012 0.006 0.012 0.004 0.014 0.004 0.014 0.004 0.014
11 0.120 0.009 0.011 0.009 0.011 0.008 0.012 0.008 0.012 0.007 0.013 0.007 0.013 0.004 0.016 0.004 0.016 0.004 0.016
10 0.134 0.009 0.011 0.009 0.011 0.008 0.012 0.008 0.012 0.007 0.013 0.007 0.013 0.004 0.016 0.004 0.016 0.004 0.016
9 0.148 0.009 0.012 0.008 0.012 0.008 0.012 0.007 0.013 0.007 0.013 0.006 0.014 0.006 0.014 0.006 0.014
8 0.165 0.009 0.012 0.008 0.012 0.008 0.012 0.007 0.013 0.007 0.013 0.006 0.014 0.006 0.014 0.006 0.014
7 0.180 0.009 0.012 0.008 0.012 0.008 0.012 0.007 0.013 0.007 0.013 0.006 0.014 0.006 0.014 0.006 0.01
A
Post-hot dipped galvanized welded tubing wall thickness tolerances shall be determined by agreement between the producer and purchaser (6.2).
B
Birmingham Wire Gauge.
A787/A787M − 22
A
TABLE 4 Wall Thickness Tolerance for Premetallic Coated As-Welded Tubing (SI Units)
Outside Diameter, mm
Wall Thickness 13 to 25, incl Over 25 to 50, incl Over 50 to 100, incl Over 100 to 150, incl Over 150 to 200, incl Over 200 to 250, incl Over 250 to 375, incl
Wall Thickness Tolerance, mm, Plus and Minus
mm Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus Plus Minus
1.0 0.04 0.08 0.08 0.20 0.08 0.20
1.5 0.10 0.18 0.10 0.15 0.08 0.23 0.05 0.25 0.05 0.25 0.05 0.25
2.0 0.15 0.20 0.15 0.20 0.13 0.23 0.10 0.25 0.10 0.25 0.10 0.25 0.08 0.28
2.5 0.20 0.25 0.20 0.25 0.18 0.28 0.15 0.30 0.15 0.30 0.10 0.30 0.10 0.35
3.0 0.22 0.27 0.23 0.28 0.20 0.30 0.18 0.33 0.18 0.33 0.10 0.40 0.10 0.40
3.5 0.23 0.28 0.23 0.28 0.20 0.30 0.18 0.33 0.18 0.33 0.10 0.40 0.10 0.40
4.0 0.23 0.30 0.20 0.30 0.18 0.33 0.18 0.33 0.15 0.40 0.15 0.40
4.5 0.23 0.30 0.20 0.30 0.18 0.33 0.18 0.33 0.15 0.40 0.15 0.40
A
Post-hot dipped galvanized welded tubing wall thickness tolerances shall be determined by agreement between the producer and purchaser (6.2).

A787/A787M − 22
TABLE 5 Diameter Tolerances for Metallic-Coated
Round Tubing (inch-pound units)
Tubing with Flash-Controlled
Wall Thickness Any Inside Flash to 0.005 in.
A
Outside Diameter Condition Tubing Only
F
Range , in. C,D
Outside Diameter,
Inside Diameter,
B
BWG in. Plus and
Plus and Minus
Minus
E
Tolerances, in.
1 1
⁄2 to 1 ⁄8, incl 22 to 16 0.028/0.065 0.0035 0.019
Over 1 ⁄8 to 2, incl 22 to 14 0.028/0.083 0.005 0.021
Over 1 ⁄8 to 2, incl 13 to 10 0.095/0.134 0.005 0.027
Over 2 to 2 ⁄2, incl 20 to 14 0.035/0.083 0.006 0.023
Over 2 to 2 ⁄2, incl 13 to 10 0.095/0.134 0.006 0.029
Over 2 ⁄2 to 3, incl 20 to 14 0.035/0.083 0.008 0.025
Over 2 ⁄2 to 3, incl 13 to 10 0.095/0.134 0.008 0.031
Over 3 to 3 ⁄2, incl 20 to 14 0.035/0.083 0.009 0.026
Over 3 to 3 ⁄2, incl 13 to 10 0.095/0.134 0.009 0.032
Over 3 ⁄2 to 4, incl 20 to 14 0.035/0.083 0.010 0.027
Over 3 ⁄2 to 4, incl 13 to 10 0.095/0.134 0.010 0.033
Over 4 to 5, incl 16 to 14 0.065/0.083 0.020 0.037
Over 4 to 5, incl 13 to 10 0.095/0.134 0.020 0.043
Over 5 to 6, incl 16 to 14 0.065/0.083 0.020 0.037
Over 5 to 6, incl 13 to 10 0.095/0.134 0.020 0.043
Over 6 to 8, incl 16 to 10 0.065/0.134 0.025 0.048
Over 6 to 8, incl 9 to 7 0.148/0.180 0.025 0.059
Over 8 to 10, incl 16 to 10 0.065/0.134 0.030 0.043
Over 8 to 10, incl 9 to 7 0.148/0.180 0.030 0.059
Over 10 to 12, incl 16 to 10 0.065/0.134 0.035 0.041
Over 10 to 12, incl 9 to 7 0.148/0.180 0.035 0.045
Over 12 to 15, incl 12 to 10 0.109/0.134 0.040 0.058
Over 12 to 15, incl 9 to 7 0.148/0.180 0.040 0.060
A
Flash controlled to 0.005 in. maximum tubing is produced to outside diameter tolerances and wall thickness tolerances, inside diameter tolerances and wall thickness
tolerances, or outside diameter tolerances and inside diameter tolerances, in which the height of the remaining inside welding flash is controlled not to exceed 0.005 in.
Any remaining flash is considered to be part of the applicable inside diameter tolerances.
B
Birmingham Wire Gauge.
C
Flash-in tubing is produced to outside diameter tolerances and wall thickness tolerances only, and the height of the inside welding flash does not exceed the wall
thickness or ⁄32 in., whichever is less.
D
Flash controlled to 0.010 in. maximum tubing consists of tubing over ⁄8 in. outside diameter which is commonly produced to outside diameter tolerances and wall
thickness tolerances only, in which the height of the remaining inside welding flash is controlled not to exceed 0.010 in.
E
The ovality shall be within the above tolerances except when the wall thickness is less than 3 % of the outside diameter, in which cases see 12.5.
F
Measured at least 2 in. from the cut end of the tubing.
8. Surface Finish
8.1 Special surface finishes as may be required for specific applications shall be provided in the purchase order by agreement
between the producer and purchaser.
9. Base Metal Chemical Composition
9.1 The chemical composition of the sheet steel base metal shall conform to the requirements of Table 1, Table 2, or the applicable
chemical requirement of Type 1, 2, 4, 5 or 6 product.
9.2 Copper-bearing steel, with 0.20 % minimum copper, may be ordered in any of the grades shown in Table 1 or Table 2.
9.3 An analysis of each heat of steel shall be made by the basic steel producer to determine the percentage of the elements
A787/A787M − 22
TABLE 6 Diameter Tolerances for Metallic-Coated Round Tubing
(SI units)
Outside Diameter Wall Thickness, Tubing with Flash-
E
Range , mm mm Any Inside Controlled
Flash Condition to 0.13 mm
A
Tubing Only
B,C
Outside Inside Diameter
Diameter,
Plus and Minus
Plus and Minus
D
Tolerances, mm
13 to 25 0.70/1.50 0.09 0.48
Over 25 to 50, incl 0.70/1.50 0.13 0.53
Over 25 to 50, incl 2.50/3.50 0.13 0.69
Over 50 to 75, incl 1.00/1.50 0.17 0.58
Over 50 to 75, incl 2.50/3.50 0.17 0.74
Over 75 to 100, incl 1.00/1.50 0.23 0.66
Over 75 to 100, incl 2.50/3.50 0.23 0.81
Over 100 to 125, 1.00/1.50 0.51 0.94
incl
Over 100 to 125, 2.50/3.50 0.51 1.09
incl
Over 125 to 150, 1.00/1.50 0.51 0.94
incl
Over 125 to 150, 2.50/3.50 0.51 1.09
incl
Over 150 to 200, 1.00/1.50 0.63 1.22
incl
Over 150 to 200, 2.50/3.50 0.63 1.50
incl
Over 200 to 250, 1.50/2.50 0.76 1.22
incl
Over 200 to 250, 2.50/3.50 0.76 1.50
incl
Over 250 to 375, 1.50/2.50 1.00 1.22
incl
Over 250 to 375, 2.50/3.50 1.00 1.50
incl
A
Flash controlled to 0.12 mm maximum tubing is produced to outside diameter
tolerances and wall thickness tolerances, inside diameter tolerances and wall
thickness tolerances, or outside diameter tolerances and inside diameter
tolerances, in which the height of the remaining inside welding flash is controlled
not to exceed 0.12 mm. Any remaining flash i
...