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Designation: A 501 – 01

Standard Specification for

Hot-Formed Welded and Seamless Carbon Steel Structural
Tubing1
This standard is issued under the fixed designation A 501; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.

1. Scope A 53/A 53M Specification for Pipe, Steel, Black and Hot-
1.1 This specification covers black and hot-dipped galva- Dipped, Zinc-Coated, Welded and Seamless2
nized hot-formed welded and seamless carbon steel square, A 370 Test Methods and Definitions for Mechanical Testing
round, rectangular, or special shape structural tubing for of Steel Products3
welded, riveted, or bolted construction of bridges and build- A 700 Practices for Packaging, Marking, and Loading
ings, and for general structural purposes. Methods for Steel Products for Domestic Shipment4
1.2 Square and rectangular tubing is furnished in sizes 1 to A 751 Test Methods, Practices, and Terminology for
10 in. (25.4 to 254 mm) across flat sides with wall thicknesses Chemical Analysis of Steel Products3
0.095 to 1.000 in. (2.41 to 25.40 mm), dependent upon size; A 941 Terminology Relating to Steel, Stainless Steel, Re-
round tubing is furnished in NPS 1⁄2 to NPS 24 (see Note 1) lated Alloys, and Ferroalloys2
inclusive, with nominal (average) wall thicknesses 0.109 to 2.2 AIAG Standard:

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1.000 in. (2.77 to 25.40 mm), dependent upon size. Special
shape tubing and tubing with other dimensions is permitted to
3. Terminology
B-1 Bar Code Symbology Standard5

requirements of this specification. (https://standards.iteh.ai)

be furnished, provided that such tubing complies with all other
3.1 Definitions—For definitions of terms used in this speci-
fication, refer to Terminology A 941.
Document4.Preview
NOTE 1—The dimensionless designator NPS (nominal pipe size) has
Ordering Information
been substituted in this standard for such traditional terms as “nominal
diameter,” “size,” and “nominal size.”
4.1 Orders for material under this specification shall contain
1.3 The following precautionary statement pertains only to information concerning as many of the following items as are
ASTM
the test method portion of this specification: This standard does A501-01
required to describe the desired material adequately:
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not purport to address all the safety concerns, if any, associ- 4.1.1 Quantity (feet or number of lengths),
ated with its use. It is the responsibility of the user of this 4.1.2 Name of material (hot-formed tubing),
standard to establish appropriate safety and health practices 4.1.3 Method of manufacture (seamless or welded) (see
and determine the applicability of regulatory limitations prior Section 6),
to use. 4.1.4 Finish (black or galvanized),
1.4 The values stated in inch-pound units are to be regarded 4.1.5 Size (outside diameter and calculated nominal wall
as the standard. The values given in parentheses are mathemati- thickness for round tubing and the outside dimensions and
cal conversions of the values in inch-pound units to SI units. calculated nominal wall thickness for square and rectangular
1.5 The text of this specification contains notes and foot- tubing (Section 11),
notes that provide explanatory material. Such notes and foot- 4.1.6 Length (random, multiple, or specific; see 12.3),
notes, excluding those in tables and figures, do not contain any 4.1.7 End condition (see 17.3),
mandatory requirements. 4.1.8 Burr removal (see 17.3),
4.1.9 Certification (see Section 19),
2. Referenced Documents
4.1.10 ASTM specification designation and year of issue,
2.1 ASTM Standards: 4.1.11 End use,

1 2
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Annual Book of ASTM Standards, Vol 01.01.
3
Stainless Steel, and Related Alloys, and is the direct responsibility of Subcommittee Annual Book of ASTM Standards, Vol 01.03.
4
A01.09 on Carbon Steel Tubular Products. Annual Book of ASTM Standards, Vol 01.05.
5
Current edition approved Mar. 10, 2001. Published May 2001. Originally Available from Automotive Industry Action Group, 26200 Lahser Road, Suite
published as A 501 – 64. Last previous edition A 501 – 99. 200, Southfield, MI 48034.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

1
 A 501 – 01
4.1.12 Special requirements, and TABLE 2 Tensile Requirements
4.1.13 Bar coding (see 20.3). Tensile strength, min, psi (MPa) 58 000 (400)
Yield strength, min, psi (MPa) 36 000 (250)
Elongation in 2 in. (50.8 mm), min, % 23
5. Process
5.1 The steel shall be made by one or more of the following
processes: open-hearth, basic-oxygen, or electric-furnace.
5.2 When steels of different grades are sequentially strand 10. Bend Test
cast, the steel producer shall identify the resultant transition 10.1 The bend test shall be made on square or rectangular
material and remove it using an established procedure that tubing manufactured in accordance with this specification.
positively separates the grades. 10.2 The bend test specimen shall be taken longitudinally
from the tubing, and shall represent the full wall thickness of
6. Manufacture material. It shall be permissible for the sides of the bend test to
6.1 The tubing shall be made by one of the following have their corners rounded out to a radius of 1⁄16 in. (1.59 mm)
processes: seamless; furnace-butt welding (continuous weld- maximum.
ing); or electric-resistance welding followed by reheating 10.3 The bend test specimen shall stand being bent cold
throughout the cross section and hot forming by a reducing or through 180°, without cracking on the outside of the bent
shaping process, or both. portion, to an inside diameter which shall have a relation to the
thickness of the specimen as prescribed in Table 3.
7. Heat Analysis
11. Dimensions
7.1 Each heat analysis shall conform to the requirements
specified in Table 1 for heat analysis. 11.1 Square Structural Tubing—The outside dimensions
(across the flats), the weight per foot, and the calculated
8. Product Analysis nominal wall thickness of common sizes of square structural
8.1 The tubing shall be capable of conforming to the tubing included in this specification are listed in Table 4.

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requirements specified in Table 1 for product analysis. 11.2 Rectangular Structural Tubing—The outside dimen-
8.2 If product analyses are made, they shall be made using sions (across the flats), the weight per foot, and the calculated
test specimens taken from two lengths of tubing from each lot nominal wall thickness of common sizes of rectangular struc-
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of 500 lengths, or fraction thereof, or two pieces of flat-rolled
stock from each lot of a corresponding quantity of flat-rolled
tural tubing included in this specification are listed in Table 5.
11.3 Round Structural Tubing—The NPS and outside diam-

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stock. Methods and practices relating to chemical analysis shall
be in accordance with Test Methods, Practices, and Terminol-
eter dimensions, the weight per foot, and the calculated
nominal wall thickness of common sizes of round structural
tubing included in this specification are listed in Table 6.
ogy A 751. Such product analyses shall conform to the
requirements specified in Table 1 for product analysis. 11.4 Special Shape Structural Tubing—The dimensions and
8.3 If both product analyses representing a lot ASTM fail to A501-01
tolerances of special shape structural tubing are available by
conformhttps://standards.iteh.ai/catalog/standards/sist/cc7a20eb-2eb2-46ea-94ef-de6625022a2b/astm-a501-01
to the specified requirements, the lot shall be rejected. inquiry and negotiation with the manufacturer.
8.4 If only one product analysis representing a lot fails to 11.5 Other Sizes—The dimensional tolerances for hot-
conform to the specified requirements, product analyses shall formed welded and seamless structural tubing manufactured in
be made using two additional test specimens taken from the lot. accordance with the requirements of this specification, but with
Both additional product analyses shall conform to the specified ordered dimensions other than those listed in Table 4, Table 5,
requirements or the lot shall be rejected. and Table 6, shall be consistent with those given in this
specification for similar sizes and type of product.
9. Tensile Requirements
12. Permissible Variations in Dimensions of Square,
9.1 The material, as represented by the test specimen, shall Round, Rectangular, and Special Shape Structural
conform to the requirements as to tensile properties prescribed Tubing
in Table 2.
9.2 The yield strength corresponding to a permanent offset 12.1 Outside Dimensions:
of 0.2 % of the gage length of the specimen or to a total 12.1.1 Round Structural Tubing—For round hot-formed
extension of 0.5 % of the gage length under load shall be structural tubing NPS 2 and over, the outside diameter shall not
determined. vary more than 61 % from the specified outside diameter. For
NPS 11⁄2 and under, the outside diameter shall not vary more
than 1⁄64 in. (0.40 mm) over or more than 1⁄32 in. (0.79 mm)
TABLE 1 Chemical Requirements under the specified outside diameter.
Composition, %
Element Heat Product
TABLE 3 Bend Test Requirements
analysis analysis
Thickness of Material, in. (mm) Ratio of Bend Diameter to
Carbon, max 0.26 0.30
Specimen Thickness
Phosphorus, max 0.035 0.045
Sulfur, max 0.035 0.045 ⁄ (19.0) and under
34 ⁄
12

Copper, when copper steel is specified, min 0.20 0.18 Over 3⁄4 to 1 (19.0 to 25.4), incl 1

2
 A 501 – 01
TABLE 4 Dimensions of Common Sizes of Square Structural TABLE 5 Dimensions of Common Sizes of Rectangular
Tubing Structural Tubing

Size Given in Outside Weight per Calculated Nominal Size Given in Outside Weight per Calculated Nominal Wall
Dimensions Across Flat Unit Length, Wall Thickness, Dimensions Across Flat Unit Length, Thickness, in. (mm)
Sides, in. (mm) lb/ft (kg/m) in. (mm) Sides, in. (mm) lb/ft (kg/m)
3 by 2 4.32 (6.43) 0.141 (3.58)
(76.2 by 50.8) 5.59 (8.32) 0.188 (4.78)
1 by 1 1.09 (1.62) 0.095 (2.41) 7.10 (10.56) 0.250 (6.35)
(25.4 by 25.4) 1.41 (2.10) 0.133 (3.38)
4 by 2 5.78 (8.60) 0.156 (3.96)
2 by 2 2.69 (4.00) 0.110 (2.79) (101.6 by 50.8) 6.86 (10.21) 0.188 (4.78)
(50.8 by 50.8) 3.04 (4.52) 0.125 (3.18) 8.80 (13.09) 0.250 (6.35)
3.65 (5.44) 0.154 (3.91)
4.31 (6.41) 0.188 (4.78) 4 by 3 6.88 (10.24) 0.156 (3.96)
(101.6 by 76.2) 8.14 (12.11) 0.188 (4.78)
21⁄2 by 21⁄2 4.32 (6.43) 0.141 (3.58)
10.50 (15.62) 0.250 (6.35)
(63.5 by 63.5) 5.59 (8.32) 0.188 (4.78)
12.69 (18.88) 0.312 (7.92)
7.10 (10.56) 0.250 (6.35)

3 by 3 5.78 (8.60) 0.156 (3.96) 5 by 3 9.31 (13.85) 0.188 (4.78)

(76.2 by 76.2) 6.86 (10.21) 0.188 (4.78) (127.0 by 76.2) 12.02 (17.89) 0.250 (6.35)
8.80 (13.09) 0.250 (6.35) 14.52 (21.61) 0.312 (7.92)
16.84 (25.06) 0.375 (9.52)
31⁄2 by 31⁄2 6.88 (10.24) 0.156 (3.96)
(88.9 by 88.9) 8.14 (12.11) 0.188 (4.78) 6 by 3 10.58 (15.74) 0.188 (4.78)
10.50 (15.62) 0.250 (6.35) (152.4 by 76.2) 13.72 (20.42) 0.250 (6.35)
12.69 (18.88) 0.312 (7.92) 16.65 (24.78) 0.312 (7.92)
19.39 (28.85) 0.375 (9.52)
4 by 4 9.31 (13.85) 0.188 (4.78)
(101.6 by 101.6) 12.02 (17.89) 0.250 (6.35) 6 by 4 11.86 (17.65) 0.188 (4.78)
14.52 (21.61) 0.312 (7.92) (152.4 by 101.6) 15.42 (22.94) 0.250 (6.35)
16.84 (25.06) 0.375 (9.52) 18.77 (27.93) 0.312 (7.92)

5 by 5
20.88

11.86
(31.07)

(17.65)
iTeh Standards
0.500 (12.70)

0.188 (4.78)
21.94 (32.65)
27.68 (41.19)
0.375
0.500
(9.52)
(12.70)

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(127.0 by 127.0) 15.42 (22.94) 0.250 (6.35) 7 by 5 14.41 (21.44) 0.188 (4.78)
18.77 (27.93) 0.312 (7.92) (177.8 by 127.0) 18.82 (28.00) 0.250 (6.35)
21.94 (32.65) 0.375 (9.52) 23.02 (34.25) 0.312 (7.92)

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27.68 (41.19) 0.500 (12.70) 27.04 (40.28) 0.375 (9.52)
34.48 (51.31) 0.500 (12.70)
6 by 6 14.41 (21.44) 0.188 (4.78)
(152.4 by 152.4) 18.82 (28.00) 0.250 (6.35)
8 by 4 14.41 (21.44) 0.188 (4.78)
23.02 (34.25) 0.312 (7.92)
(203.2 by 101.6) 18.82 (28.00) 0.250 (6.35)
27.04 (40.28) 0.375 (9.52)
34.48 (51.31) ASTM A501-01
0.500 (12.70)
23.02
27.04
(34.25)
(40.28)
0.312
0.375
(7.92)
(9.52)
7 by 7 https://standards.iteh.ai/catalog/standards/sist/cc7a20eb-2eb2-46ea-94ef-de6625022a2b/astm-a501-01
16.85 (25.07) 0.188 (4.78) 34.48 (51.31) 0.500 (12.70)
(177.8 by 177.8) 22.04 (32.80) 0.250 (6.35)
26.99 (39.16) 0.312 (7.92) 8 by 6 16.85 (25.07) 0.188 (4.78)
31.73 (47.21) 0.375 (9.52) (203.2 by 152.4) 22.04 (32.80) 0.250 (6.35)
40.55 (60.34) 0.500 (12.70) 26.99 (39.16) 0.312 (7.92)
31.73 (47.21) 0.375 (9.52)
8 by 8 25.44 (37.85) 0.250 (6.35) 40.55 (60.34) 0.500 (12.70)
(203.2 by 203.2) 31.24 (46.49) 0.312 (7.92)
36.83 (54.80) 0.375 (9.52) 10 by 6 25.44 (37.85) 0.250 (6.35)
47.35 (70.46) 0.500 (12.70) (254.0 by 152.4) 31.24 (46.49) 0.312 (7.92)
56.98 (84.79) 0.625 (15.88) 36.83 (54.80) 0.375 (9.52)
65.73 (97.81) 0.750 (19.05) 47.35 (70.46) 0.500 (12.70)

10 by 10 32.23 (47.96) 0.250 (6.35)

(254.0 by 254.0) 39.74 (59.13) 0.312 (7.92)
47.03 (69.98) 0.375 (9.52) using its length and the applicable weight per unit length given
60.95 (90.69) 0.500 (12.70) in Table 4, Table 5, or Table 6.
73.98 (110.08) 0.625 (15.88) 12.3 Length—Structural tubing is commonly produced in
86.13 (128.16) 0.750 (19.05)
107.79 (160.39) 1.000 (25.40) random lengths of 16 to 22 ft. (4.9 to 6.7 m) or 32 to 44 ft. (9.8
to 13.4 m), in multiple lengths, and in specific lengths. When
specific lengths are ordered, the permissible variations in
12.1.2 Square, Rectangular, and Special Shape Structural length shall be as given in Table 8.
Tubing—The outside dimensions, measured across the flats at 12.4 Straightness—The permissible variation for straight-
positions at least 2 in. (50.8 mm) from the ends of the tubing, ness of structural tubing shall be 1⁄8 in. times the number of feet
shall not vary from the specified outside dimensions by more (10.4 mm times the number of metres) of total length divided
than the applicable amount given in Table 7, which includes an by 5.
allowance for convexity or concavity. 12.5 Squareness of Sides—For perpendicular and rectangu-
12.2 Weight—The weight of the structural tubing shall be lar tubing, adjacent sides shall be square (90°), with a permis-
not more than 3.5 % under its theoretical weight, as calculated sible variation of 62°.