ASTM A500/A500M-23

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Designation: A500/A500M − 21a A500/A500M − 23
Standard Specification for
Cold-Formed Welded and Seamless Carbon Steel Structural
Tubing in Rounds and Shapes
This standard is issued under the fixed designation A500/A500M; 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 cold-formed welded and seamless carbon steel round, square, rectangular, or special structural
tubular shapes for welded, riveted, or bolted construction of bridges and buildings, and for general structural purposes.
1.2 This tubing is produced in both welded and seamless sizes with a periphery of 88 in. [2235 mm] or less, and a specified wall
thickness of 1.000 in. [25.4 mm] or less. Grade D requires heat treatment.
NOTE 1—Products manufactured to this specification may not be suitable for those applications such as dynamically loaded elements in welded structures,
etc., where low-temperature notch-toughness properties, which are typically measured by Charpy Impact testing, may be important. There are other
ASTM standards that do have CVN requirements and may be more suitable for those applications.
1.3 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. The
inch-pound units shall apply unless the “M” designation of this specification is specified in the order.
1.4 The text of this specification contains notes and footnotes that provide explanatory material. Such notes and footnotes,
excluding those in tables and figures, do not contain any mandatory requirements.
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:
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A700 Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment
A751 Test Methods and Practices for Chemical Analysis of Steel Products
A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
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 Sept. 1, 2021Nov. 1, 2023. Published September 2021November 2023. Originally approved in 1964. Last previous edition approved in 2021 as
A500/A500M – 21.A500/A500M – 21a. DOI: 10.1520/A0500_A0500M-21A.10.1520/A0500_A0500M-23.
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
A500/A500M − 23
2.2 Military Standards:
MIL-STD-129 Marking for Shipment and Storage
MIL-STD-163 Steel Mill Products, Preparation for Shipment and Storage
2.3 Federal Standards:
Fed. Std. No. 123 Marking for Shipment
Fed. Std. No. 183 Continuous Identification Marking of Iron and Steel Products
2.4 AIAG Standard:
B-1 Bar Code Symbology Standard
2.5 Steel Tube Institute:
Methods to Check Dimensional Tolerances on Hollow Structural Sections
3. Terminology
A941.
3.1 Definitions—For definitions of terms used in this specification, refer to Terminology
4. Ordering Information
4.1 Orders for material under this specification shall contain information concerning as many of the following items as are required
to describe the desired material adequately:It shall be the responsibility of the purchaser to specify all requirements that are
necessary for the products under this specification. Such requirements to be considered include, but are not limited to, the
following:
4.1.1 Quantity (feet [metres] or number of lengths),
4.1.2 Name of material (cold-formed tubing),
4.1.3 Method of manufacture (seamless or welded),
4.1.4 Grade (B, C, or D),
4.1.5 Size (outside diameter and wall thickness for round tubing, and outside dimensions and wall thickness for square and
rectangular tubing),
4.1.6 Copper-containing steel (see Table 1), if applicable,
4.1.7 Length (random, multiple, specific; see 11.3),
4.1.8 End condition (see 16.3),
TABLE 1 Chemical Requirements
Composition, %
Grades B and D Grade C
Element
Heat Product Heat Product
Analysis Analysis Analysis Analysis
A
Carbon, max 0.26 0.30 0.23 0.27
A
Manganese, max 1.35 1.40 1.35 1.40
Phosphorus, max 0.035 0.045 0.035 0.045
Sulfur, max 0.035 0.045 0.035 0.045
B
Copper, min 0.20 0.18 0.20 0.18
A
For each reduction of 0.01 percentage point below the specified maximum for
carbon, an increase of 0.06 percentage point above the specified maximum for
manganese is permitted, up to a maximum of 1.50 % by heat analysis and 1.60 %
by product analysis.
B
If copper-containing steel is specified in the purchase order.
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Available from Automotive Industry Action Group (AIAG), 26200 Lahser Rd., Suite 200, Southfield, MI 48033, http://www.aiag.org.
Available from the Steel Tube Institute (STI), 2516 Waukegan Rd., STE 172, Glenview, IL 60025-1774, https://steeltubeinstitute.org.
A500/A500M − 23
4.1.9 Burr removal (see 16.3),
4.1.10 Certification (see Section 18),
4.1.11 ASTM specification designation and year of issue,
4.1.12 End use,
4.1.13 Special requirements, and
4.1.14 Bar coding (see 19.3).), and
4.1.15 Destructive Weld Tests required in addition to or in lieu of those listed (see 10.8).
5. Process
5.1 The steel shall be made by one or more of the following processes: basic-oxygen or electric-furnace.
5.2 When steels of different grades are sequentially strand cast, the steel producer shall identify the resultant transition material
and remove it using an established procedure that positively separates the grades.
6. Manufacture
6.1 The tubing shall be made by a seamless or welding process.
6.2 Welded tubing shall be made from flat-rolled steel by the electric-resistance-welding process. The longitudinal butt joint of
welded tubing shall be welded across its thickness in such a manner that the structural design strength of the tubing section is
assured.
6.3 The weld shall not be located within the radius of the corners of any tubular shapes unless specified by the purchaser.
NOTE 2—Welded tubing is normally furnished without removal of the inside flash.
6.4 Except as required by 6.5, it shall be permissible for the tubing to be stress relieved or annealed.
6.5 Grade D tubing shall be heat treated at a temperature of at least 1100 °F [590 °C] for one hour per inch [25 mm] of thickness.
7. Heat Analysis
7.1 Each heat analysis shall conform to the requirements specified in Table 1 for heat analysis.
8. Product Analysis
8.1 The tubing shall be capable of conforming to the requirements specified in Table 1 for product analysis.
8.2 If product analyses are made, they shall be made using test specimens taken from two lengths of tubing from each lot of 500
lengths, or fraction thereof, or two pieces of flat-rolled stock from each lot of a corresponding quantity of flat-rolled stock. Methods
and practices relating to chemical analysis shall be in accordance with Test Methods, Practices, and Terminology A751. Such
product analyses shall conform to the requirements specified in Table 1 for product analysis.
8.3 If both product analyses representing a lot fail to conform to the specified requirements, the lot shall be rejected.
8.4 If only one product analysis representing a lot fails to conform to the specified requirements, product analyses shall be made
using two additional test specimens taken from the lot. Both additional product analyses shall conform to the specified
requirements or the lot shall be rejected.
A500/A500M − 23
9. Tensile Requirements
9.1 The material, as represented by the test specimen, shall conform to the requirements as to tensile properties prescribed in Table
2.
10. Flattening Test, Flaring Test, and Wedge Crush Test
10.1 The flattening test shall be made on round structural tubing. A flattening test is not required for shaped structural
tubing.flaring test on round tubing up to and including 10 in. in diameter can be made if stated in the purchase order. Either a
flattening test, flaring test or a wedge crush test shall be made on square and rectangular tubular shapes with a side up to and
including 10 in. except when the customer specifies the weld to be located in the corner. Destructive weld tests on tubular shapes
that are not round, square or rectangular are to be agreed upon in advance between the producer and purchaser.
10.2 For welded round structural tubing, a test specimen at least 4 in. [100 mm] in length shall be flattened cold between parallel
plates in three steps, with the weld located 90° from the line of direction of force. During the first step, which is a test for ductility
of the weld, no cracks or breaks on the inside or outside surfaces of the test specimen shall be present until the distance between
the plates is less than two-thirds of the specified outside diameter of the tubing. For the second step, no cracks or breaks on the
inside or outside parent metal surfaces of the test specimen, except as provided for in 10.5, shall be present until the distance
between the plates is less than one-half of the specified outside diameter of the tubing. During the third step, which is a test for
soundness, the flattening shall be continued until the test specimen breaks or the opposite walls of the test specimen meet. Evidence
of laminated or unsound material or of incomplete weld that is revealed during the entire flattening test shall be cause for rejection.
3 1
10.3 For seamless round structural tubing 2 ⁄8 in. [60 mm] specified outside diameter and larger, a specimen not less than 2 ⁄2 in.
[65 mm] in length shall be flattened cold between parallel plates in two steps. During the first step, which is a test for ductility,
no cracks or breaks on the inside or outside surfaces, except as provided for in 10.5, shall occur until the distance between the plates
is less than the value of “H” calculated by the following equation:
H 5 11e t/ e1t/D (1)
~ ! ~ !
where:
H = distance between flattening plates, in. [mm],
e = deformation per unit length (constant for a given grade of steel, 0.09 for Grade A, 0.07 for Grade B, and 0.06 for Grade
C),
e = deformation per unit length (constant for a given grade of steel, 0.07 for Grade B, and 0.06 for Grade C),
t = specified wall thickness of tubing, in. [mm], and
D = specified outside diameter of tubing, in. [mm].
During the second step, which is a test for soundness, the flattening shall be continued until the specimen breaks or the opposite
walls of the specimen meet. Evidence of laminated or unsound material that is revealed during the entire flattening test shall be
cause for rejection.
TABLE 2 Tensile Requirements
Round, Square, Rectangular, and Special Tubular Shapes
Grade B Grade C Grade D
Tensile strength, min, 58 000 62 000 58 000
psi [MPa] [400] [425] [400]
Yield strength, min, psi 46 000 50 000 36 000
[MPa] [315] [345] [250]
Elongation in 2 in. [50
A B A
23 21 23
C
mm], min, %
A
Applies to specified wall thicknesses (t ) equal to or greater than 0.180 in. [4.57
mm]. For lighter specified wall thicknesses, the minimum elongation values shall
be calculated by the formula: percent elongation in 2 in. [50 mm] = 61t + 12,
rounded to the nearest percent. For A500M use the following formula: 2.4t + 12,
rounded to the nearest percent.
B
Applies to specified wall thicknesses (t ) equal to or greater than 0.120 in. [3.05
mm]. For lighter specified wall thicknesses, the minimum elongation values shall
be by agreement with the manufacturer.
C
The minimum elongation values specified apply only to tests performed prior to
shipment of the tubing.
A500/A500M − 23
10.4 Surface imperfections not found in the test specimen before flattening, but revealed during the first step of the flattening test,
shall be judged in accordance with Section 15.
10.5 When low D-to-t ratio tubulars are tested, because the strain imposed due to geometry is unreasonably high on the inside
surface at the 6 and 12 o’clock locations, cracks at these locations shall not be cause for rejection if the D-to-t ratio is less than
10.
10.6 Flaring Test—A section of tube shall stand being flared with a tool having a 60° included angle until the weld area has been
expanded a minimum of 15 % of the inside dimension for rounds and squares without any cracking in the weld area. For rectangles,
the side containing the weld area and the side opposite the weld area shall be expanded a minimum of 15 % based on the average
of the smallest and largest inside dimensions without any cracking in the weld area. The cone tool shall not have a weld relief
groove. Cracking in the corners of square, rectangular, or other tubular shapes after flaring is not grounds for rejection.
10.7 Wedge Crush Test—A test specimen at least 4 in. [100 mm] in length shall be placed under the hydraulic press ram with the
weld directly underneath the tapered ram wedge. The tapered ram wedge shall be tapered at 30° and rounded at the contact point
to a ⁄2 in. radius. No cracks or breaks on the inside or outside surfaces of the test specimen shall be present until the tube has
collapsed to at least one half its specified dimension.
10.8 Other destructive weld tests may be requested in lieu of or in addition to the tests listed. The purchaser should contact the
producer to determine their availability.
11. Permissible Variations in Dimensions
11.1 Outside Dimensions:
11.1.1 Round Structural Tubing—The outside diameter shall not vary more than 60.5 %, rounded to the nearest 0.005 in. [0.1
mm], from the specified outside diameter for specified outside diameters 1.900 in. [48 mm] and smaller, and 6 0.75 %, rounded
to the nearest 0.005 in. [0.1 mm], from the specified outside diameter for specified outside diameters 2.00 in. [5 cm] and
...