ASTM A706/A706M : 08a

Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement

Standard Details

1.1 General—This specification covers deformed and plain low-alloy steel bars in cut lengths or coils for concrete reinforcement intended for applications where restrictive mechanical properties and chemical composition are required for compatibility with controlled tensile property applications or to enhance weldability. The standard sizes and dimensions of deformed bars and their number designations are given in Table 1. The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables, shall not be considered as requirements of this specification.

1.2 Grade—Bars are of a single minimum yield strength level: namely, 60 000 psi [420 MPa], designated as Grade 60 [420].

1.3 Plain bars, in sizes up to and including 2 ½ in. [63.5 mm] in diameter in coils or cut lengths, when ordered, shall be furnished under this specification. For ductility properties (elongation and bending), test provisions of the nearest smaller nominal diameter deformed bar size shall apply.

1.4 Controlled Tensile Properties—This specification limits mechanical properties (Table 2) to provide the desired yield/tensile properties for controlled tensile property applications.

1.5 Welding—This specification limits chemical composition (6.2) and carbon equivalent (6.4) to enhance the weldability of the material. When steel is to be welded, a welding procedure suitable for the chemical composition and intended use or service should be used. The use of the latest edition of AWS D1.4/D1.4M is recommended. This document describes the proper selection of the filler metals, preheat/interpass temperatures, as well as, performance and procedure qualification requirements.

1.6 This specification is applicable for orders in either inch-pound units (Specification A 706) or in SI units [Specification A 706M].

1.7 The values stated in either inch-pound units or SI units are to be regarded as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.

1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

TABLE 1 Deformed Bar Designation Numbers, Nominal Weights [Masses], Nominal Dimensions, and Deformation Requirements

Bar Desig- nation No.^A	Nominal Weight, lb/ft [Nominal Mass, kg/m]	Nominal Dimensions^B			Deformation Requirements, in. [mm]
Bar Desig- nation No.^A	Nominal Weight, lb/ft [Nominal Mass, kg/m]	Diameter, in. [mm]	Cross-Sectional Area in.² [mm²]	Perimeter, in. [mm]	Maximum Average Spacing	Minimum Average Height	Maximum Gap (Chord of 12.5 % of Nominal Perimeter)

3 [10]	0.376 [ 0.560]	0.375 [ 9.5]	0.11 [ 71]	1.178 [ 29.9]	0.262 [ 6.7]	0.015 [0.38]	0.143 [ 3.6]
4 [13]	0.668 [ 0.994]	0.500 [12.7]	0.20 [ 129]	1.571 [ 39.9]	0.350 [ 8.9]	0.020 [0.51]	0.191 [ 4.9]
5 [16]	1.043 [ 1.552]	0.625 [15.9]	0.31 [ 199]	1.963 [ 49.9]	0.437 [11.1]	0.028 [0.71]	0.239 [ 6.1]
6 [19]	1.502 [ 2.235]	0.750 [19.1]	0.44 [ 284]	2.356 [ 59.8]	0.525 [13.3]	0.038 [0.97]	0.286 [ 7.3]
7 [22]	2.044 [ 3.042]	0.875 [22.2]	0.60 [ 387]	2.749 [ 69.8]	0.612 [15.5]	0.044 [1.12]	0.334 [ 8.5]
8 [25]	2.670 [ 3.973]	1.000 [25.4]	0.79 [ 510]	3.142 [ 79.8]	0.700 [17.8]	0.050 [1.27]	0.383 [ 9.7]
9 [29]	3.400 [ 5.060]	1.128 [28.7]	1.00 [ 645]	3.544 [ 90.0]	0.790 [20.1]	0.056 [1.42]	0.431 [10.9]
10 [32]	4.303 [ 6.404]	1.270 [32.3]	1.27 [ 819]	3.990 [101.3]	0.889 [22.6]	0.064 [1.63]	0.487 [12.4]
11 [36]	5.313 [ 7.907]	1.410 [35.8]	1.56 [1006]	4.430 [112.5]	0.987 [25.1]	0.071 [1.80]	0.540 [13.7]
14 [43]	7.65 [11.38]	1.693 [43.0]	2.25 [1452]	5.32 [135.1]	1.185 [30.1]	0.085 [2.16]	0.648 [16.5]
18 [57]	13.60 [20.24]	2.257 [57.3]	4.00 [2581]	7.09 [180.1]	1.58 [40.1]	0.102 [2.59]	0.864 [21.9]

^A Bar numbers are based on the number of eighths of an inch included in the nominal diameter of the bars [bar numbers approximate the number of millimetres of the nominal diameter of the bar].

^B The nominal dimensions of a deformed bar are equivalent to those of a plain round bar having the same weight [mass] per foot [metre] as the deformed bar.

TABLE 2 Tensile Requirements

Tensile strength, min, psi [MPa]	80 000 [550]^A
Yield strength, min, psi [MPa]	60 000 [420]
Yield strength, max, psi [MPa]	78 000 [540]
Elongation in 8 in. [203.2 mm], min, %
Bar Designation Nos.
3, 4, 5, 6 [10, 13, 16, 19]	14
7, 8, 9, 10, 11 [22, 25, 29, 32, 36]	12
14, 18 [43, 57]	10