Designation: A704/A704M − 06 (Reapproved 2011)

Standard Specification for

Welded Steel Plain Bar or Rod Mats for Concrete
Reinforcement1
This standard is issued under the fixed designation A704/A704M; 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 2.3 U.S. Federal Standard:3

1.1 This specification covers material in mat (or sheet) form Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
fabricated from hot-rolled, plain steel bars or rods to be used
for the reinforcement of concrete. Mats consist of two layers of 3. Ordering Information
bars or rods which are assembled by welding at right angles to 3.1 It shall be the responsibility of the purchaser to specify
each other. all requirements that are necessary for material ordered to this
1.2 This specification is applicable for orders in either specification. Such requirements shall include, but are not
inch-pound units (as A704) or in SI units [as A704M]. limited to, the following:
3.1.1 Quantity, no. of mats or area, or both;
1.3 The values stated in either inch-pound units or SI units
3.1.2 Size and spacing of steel bars or rods in each direction;
are to be regarded as standard. Within the text, the SI units are
3.1.3 Plain bar or rod;
shown in brackets. The values stated in each system are not
exact equivalents; therefore, each system must be used inde- 3.1.4 Grade required (Grade 40 or 60 [280 or 420] as
pendently of the other. Combining values from the two systems appropriate);
may result in nonconformance with this specification. 3.1.5 Type of steel, as appropriate (see Section 4); and
3.1.6 ASTM designation and year of issue.
2. Referenced Documents NOTE 1—A typical ordering description is as follows: 1000 welded bar
2.1 ASTM Standards:2 mats; Grade 40; to ASTM A704 – ______. 6 by 12 in.; 1⁄2 in. diameter by
A185/A185M Specification for Steel Welded Wire Rein- 120 in. longitudinal tip to tip, outer bars spaced 54 in.; 1⁄2 in. diameter by
60 in. transverse, outer bars spaced 108 in. [1000 welded bar mats; Grade
forcement, Plain, for Concrete 280; to ASTM A704M – ______. 150 by 300 mm; 12 mm diameter by
A615/A615M Specification for Deformed and Plain Carbon- 3000 mm longitudinal tip-to-tip, outer bars spaced 1350 mm; 12 mm
Steel Bars for Concrete Reinforcement diameter by 1500 mm transverse, outer bars spaced 2750 mm].
A497/A497M Specification for Steel Welded Wire Rein-
forcement, Deformed, for Concrete 4. Materials
A700 Practices for Packaging, Marking, and Loading Meth- 4.1 Plain bars or rods of Grades 40 and 60 [280 and 420]
ods for Steel Products for Shipment used in the manufacture of mats shall conform to Specification
A706/A706M Specification for Low-Alloy Steel Deformed A615/A615M or Specification A706/A706M.
and Plain Bars for Concrete Reinforcement
4.2 Maximum size of bar and rod material shall be 3⁄4 in. [19
2.2 U.S. Military Standard:3
mm] nominal diameter. Minimum size of rod material shall be
MIL-STD-29 Marking for Shipment and Storage 7⁄32 in. [6 mm] nominal diameter.

1
5. Fabrication
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee 5.1 Fabricated mats shall be composed of two layers of
A01.05 on Steel Reinforcement.
Current edition approved Nov. 1, 2011. Published November 2011. Originally
plain bars or rods substantially parallel and perpendicular to
approved in 1974. Last previous edition approved in 2006 as A704/A704M – 06. each other.
DOI: 10.1520/A0704_A0704M-06R01.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.2 Assembly—Mats shall be assembled by means of weld-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM ing to provide attachment at all intersections.
Standards volume information, refer to the standard’s Document Summary page on 5.2.1 Welded joints shall withstand normal shipping and
the ASTM website.
3
handling without becoming broken, but the presence of broken
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. Or visit: http:// welds, regardless of cause, shall not constitute cause for
assist.daps.dla.mil/online. rejection unless the number of broken welds per sheet exceed

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 A704/A704M − 06 (2011)
1 % of the total, provided that not more than one half of the 8.2 Rust, seams, surface irregularities, or mill scale shall not
permissible maximum number of broken welds are located on be cause for rejection provided the weight, dimensions, cross-
any one bar or rod. sectional area, and tensile properties of a hand wire brushed
5.2.2 Welding shall be done in such a manner that the test specimen are not less than the requirements of this
minimum tensile strength, yield strength, and elongation re- specification.
quirements for material as described in Section 4 shall be met
when a specimen is tested across a point of weld. Weld shear 9. Rejection and Retests
strength requirements shall be in compliance with Section 6. 9.1 Fabricated mats that do not meet the requirements of
this specification shall be rejected and reported to the manu-
6. Mechanical Requirements
facturer within 5 working days from the receipt of samples by
6.1 Strength of Connections in Welded Plain Bar or Rod the purchaser.
Mats—In order to assure adequate weld shear strength between
9.2 When a test specimen fails to meet the provisions of
longitudinal and transverse bar or rod, weld shear strength
5.2.2, two additional samples shall be selected and tested. All
tests, as described in 6.3.2, shall be made. The minimum
retest specimens shall meet the requirements of this specifica-
average shear value shall not be less than 25 000 lbf [172 N]
tion.
multiplied by the nominal area of the larger bar or rod in in.2
[mm2]. 9.3 When a test specimen fails to meet the provisions of 6.1,
all of the remaining welds on the transverse member shall be
6.2 Number of Tests:
tested and the average of all tests (including the original test)
6.2.1 One bar or rod of each size or grade to be used in the
shall meet the requirements specified in 6.1.
fabrication of the mat shall be tested for conformance with the
provisions of 4.1 or 4.2 for each 75 000 ft2[7000 m2] of mats 10. Inspection and Test Reports
or fraction thereof.
10.1 Inspection—The inspector representing the purchaser
6.2.2 One sample consisting of longitudinal bars or rods
shall have free entry, at all times while work on the contract of
with not less than two connections on the same transverse bar
the purchaser is being performed, to all parts of the manufac-
or rod shall be taken and tested for conformance with the
turer’s plant which concern the fabrication of the mats ordered.
provisions of 5.2.2 and 6 from each 75 000 ft2 [7000 m2] of
The manufacturer shall afford the inspector all reasonable
mats or fractions thereof.
facilities to satisfy him that the mats are being furnished in
6.3 Test Methods: accordance with this specification. All tests and inspection
6.3.1 Tension test specimens for determining conformance shall be made at the place of fabrication prior to shipment,
with 5.2.2 shall have a welded joint located approximately at unless otherwise specified, and shall be so conducted as not to
the center of the bar or rod being tested, and the cross bar or interfere unnecessarily with fabricating operations. Inspection
rod shall extend approximately 1 in. [25 mm] beyond each as to general workmanship shall be visual.
side. All unit stress determinations shall be based on the
10.2 Test Reports on Bar Material—The manufacturer shall
nominal area calculated using the nominal diameter specified.
supply test reports showing that the material used in the
6.3.2 Weld shear tests for determining conformance with the
fabrication of the mats as delivered has fulfilled the tension and
requirements of 6.1 shall be conducted with a fixture as
bend test requirements of the specified type and grade de-
described in Section 11 of Specification A185/A185M or
scribed in Section 4, which reports shall show the manufactur-
Section 8 of Specification A497/A497M.
er’s test identification numbers, including the identity of the
7. Size, Dimensions, and Tolerances material.
7.1 Size and Spacing Dimensions: 10.3 A material test report, certificate of inspection, or
7.1.1 The sizes, spacings, dimensions, and arrangement of similar document printed from or used in electronic form from
the bar or rod mats shall conform to the design specified by the an electronic data interchange (EDI) transmission shall be
purchaser. Bars or rods shall extend beyond exterior intersec- regarded as having the same validity as a counterpart printed in
tions a distance of not less than 1 in. [25 mm]. The spacing of the certifier’s facility. The content of the EDI transmitted
bars or rods shall average that specified in the design, and the document must meet the requirements of the invoked ASTM
space between individual bars or rods shall not vary more than standard(s) and conform to any existing EDI agreement be-
1⁄4 in. [6 mm] from that specified. tween the purchaser and the supplier. Notwithstanding the
7.1.2 Where bars or rods of two sizes are used, the nominal absence of a signature, the organization submitting the EDI
area of the smaller size shall not be less than 70 % of the area transmission is responsible for the content of the report.
of the larger size. NOTE 2—The industry definition as invoked here is: EDI is the
7.2 Width and Length Tolerances—The overall length or computer-to-computer exchange of business information in a standard
width of the mats shall not be more than 1 in. [25 mm] greater format such as ANSI ASC X12.
or less than the specified dimension. 10.4 For Government Procurement Only—Except as other-
wise specified in the contract, the contractor is responsible for
8. Finish and Surface Condition the performance of all inspection and test requirements speci-
8.1 The finished mats shall be free of injurious defects in fied herein and may use his own or any other suitable facilities
material or workmanship. for the performance of all inspection and test requirements

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 A704/A704M − 06 (2011)
specified herein, unless disapproved by the purchaser at the 12.2 When specified in the contract or order, and for direct
time of purchase. The purchaser shall have the right to perform procurement by or direct shipment to the U.S. Government,
any of the inspections and tests at the same frequency as set marking for shipment, in addition to requirements specified in
forth in this specification, where such inspections are deemed the contract or order, shall be in accordance with MIL-STD-29
necessary to ensure that material conforms to prescribed for military agencies and with Fed. Std. No. 123 for civil
requirements. agencies.
11. Rehearing 12.3 Each bundle of mats shall be marked with a suitable
11.1 Samples tested in accordance with this specification tag showing the order number, name of the manufacturer, size,
that represent rejected material shall be preserved for two and grade of the material used.
weeks from the date rejection is reported to the manufacturer.
In case of dissatisfaction with the results of the tests, the 13. Keywords
manufacturer may make claim for a hearing within that time.
13.1 concrete reinforcement; mats; steel bars; steel rods
12. Packaging and Package Marking
12.1 Packaging, marking, and loading for shipment shall be
in accordance with Practices A700.

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