SPECIFICATION FOR CARBON STRUCTURAL STEEL
(Identical with ASTM Specification A36/A36M-19.)
1. Scope
1.1 This specification covers carbon steel shapes, plates, and bars of structural quality for use in riveted, bolted, or welded construction of bridges and buildings, and for general structural purposes.
1.2 Supplementary requirements are provided for use where additional testing or additional restrictions are required by the purchaser. Such requirements apply only when specified in the purchase order.
1.3 When the steel is to be welded, a welding procedure suitable for the grade of steel and intended use or service is to be utilized. See Appendix X3 of Specification A6/A6M for information on weldability.
1.4 The text of this specification contains notes or footnotes, or both, that provide explanatory material. Such notes and footnotes, excluding those in tables and figures, do not contain any mandatory requirements.
1.5 For structural products produced from coil and furnished without heat treatment or with stress relieving only, the additional requirements, including additional testing requirements and the reporting of additional test results, of Specification A6/A6M apply.
1.6 The values stated in either inch-pound units or SI units are to be regarded separately 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 is to be used independently of the other, without combining values in any way.
1.7 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:
- A6/A6M Specification for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling
- A27/A27M Specification for Steel Castings, Carbon, for General Application
- A307 Specification for Carbon Steel Bolts, Studs, and Threaded Rod 60 000 PSI Tensile Strength
- A500 Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes
- A501 Specification for Hot-Formed Welded and Seamless Carbon Steel Structural Tubing
- A502 Specification for Rivets, Steel, Structural
- A563 Specification for Carbon and Alloy Steel Nuts
- A563M Specification for Carbon and Alloy Steel Nuts (Metric)
- A668/A668M Specification for Steel Forgings, Carbon and Alloy, for General Industrial Use
- A1011/A1011M Specification for Steel, Sheet and Strip, Hot-Rolled, Carbon, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, and Ultra-High Strength
- A1018/A1018M Specification for Steel, Sheet and Strip, Heavy-Thickness Coils, Hot-Rolled, Carbon, Commercial, Drawing, Structural, High-Strength Low-Alloy, High-Strength Low-Alloy with Improved Formability, and Ultra-High Strength
- F568M Specification for Carbon and Alloy Steel Externally Threaded Metric Fasteners (Metric) (Withdrawn 2012)
- F1554 Specification for Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength
- F3125/F3125M Specification for High Strength Structural Bolts and Assemblies, Steel and Alloy Steel, Heat Treated, Inch Dimensions 120 ksi and 150 ksi Minimum Tensile Strength, and Metric Dimensions 830 MPa and 1040 MPa Minimum Tensile Strength
3. Appurtenant Materials
3.1 When components of a steel structure are identified with this ASTM designation but the product form is not listed in the scope of this specification, the material shall conform to one of the standards listed in Table 1 unless otherwise specified by the purchaser.
| Material | ASTM Designation |
|---|---|
| Steel rivets | A502, Grade 1 |
| Bolts | A307, Grade A or F568M, Class 4.6 |
| High-strength bolts | F3125/F3125M, Grade A325 or A325M |
| Steel nuts | A563 or A563M |
| Cast steel | A27/A27M, Grade 65-35 [450-240] |
| Forgings (carbon steel) | A668/A668M, Class D |
| Hot-rolled sheets and strip | A1011/A1011M, SS Grade 36 [250] Type 1 or Type 2 or A1018/A1018M, SS Grade 36 [250] Type 1 or Type 2 |
| Cold-formed tubing | A500, Grade B |
| Hot-formed tubing | A501 |
| Anchor bolts | F1554, Grade 36 |
NOTE 1 — The specifier should be satisfied of the suitability of these materials for the intended application. Chemical composition or mechanical properties, or both, may be different than specified in A36/A36M.
4. General Requirements for Delivery
4.1 Structural products furnished under this specification shall conform to the requirements of the current edition of Specification A6/A6M, for the specific structural product ordered, unless a conflict exists in which case this specification shall prevail.
4.2 Coils are excluded from qualification to this specification until they are processed into a finished structural product. Structural products produced from coil means structural products that have been cut to individual lengths from a coil. The processor directly controls, or is responsible for, the operations involved in the processing of a coil into a finished structural product. Such operations include decoiling, leveling or straightening, hot-forming or cold-forming (if applicable), cutting to length, testing, inspection, conditioning, heat treatment (if applicable), packaging, marking, loading for shipment, and certification.
NOTE 1 — For structural products produced from coil and furnished without heat treatment or with stress relieving only, two test results are to be reported for each qualifying coil. Additional requirements regarding structural products produced from coil are described in Specification A6/A6M.
5. Bearing Plates
5.1 Unless otherwise specified, plates used as bearing plates for bridges shall be subjected to mechanical tests and shall conform to the tensile requirements of Section 8.
5.2 Unless otherwise specified, mechanical tests shall not be required for plates over 1½ in. [40 mm] in thickness used as bearing plates in structures other than bridges, subject to the requirement that they shall contain 0.20 to 0.33 % carbon by heat analysis, that the chemical composition shall conform to the requirements of Table 3 in phosphorus and sulfur content, and that a sufficient discard shall be made to secure sound plates.
6. Materials and Manufacture
6.1 The steel shall be killed.
7. Chemical Composition
7.1 The heat analysis shall conform to the requirements prescribed in Table 3, except as specified in 5.2.
7.2 The steel shall conform on product analysis to the requirements prescribed in Table 3, subject to the product analysis tolerances in Specification A6/A6M.
| Product Thickness, in. [mm] | Shapes All | Bars; Plates ≤ 15-in. [380 mm] WidthB | |||||||
|---|---|---|---|---|---|---|---|---|---|
| To ¾ [20], incl | Over ¾ to 1½ [20 to 40], incl | Over 1½ to 2½ [40 to 65], incl | Over 2½ to 4 [65 to 100], incl | Over 4 [100] | To ¾ [20], incl | Over ¾ to 1½ [20 to 40], incl | Over 1½ to 4 [100], incl | Over 4 [100] | |
| Carbon, max, % | 0.26 | 0.25 | 0.25 | 0.26 | 0.27 | 0.29 | 0.26 | 0.27 | 0.28 |
| Manganese, % | — | — | 0.80-1.20 | 0.80-1.20 | 0.85-1.20 | — | 0.60-0.90 | 0.60-0.90 | 0.60-0.90 |
| Phosphorus, max, % | 0.04 | 0.030 | 0.030 | 0.030 | 0.030 | 0.04 | 0.04 | 0.04 | 0.04 |
| Sulfur, max, % | 0.05 | 0.030 | 0.030 | 0.030 | 0.030 | 0.05 | 0.05 | 0.05 | 0.05 |
| Silicon, % | 0.40 max | 0.40 max | 0.40 max | 0.15-0.40 | 0.15-0.40 | 0.40 max | 0.40 max | 0.40 max | 0.40 max |
| Copper, min, % when copper steel is specified | 0.20 | 0.20 | 0.20 | 0.20 | 0.20 | 0.20 | 0.20 | 0.20 | 0.20 |
NOTE 1 — Where "..." appears in this table, there is no requirement. The heat analysis for manganese shall be determined and reported as described in the heat analysis section of Specification A6/A6M.
Manganese content of 0.85-1.35% and silicon content of 0.15-0.40% is required for shapes with flange thickness over 3 in. [75 mm]. For each reduction of 0.01 percentage point below the specified carbon maximum, an increase of 0.06 percentage point manganese above the specified maximum will be permitted, up to the maximum of 1.35%.
8. Tension Test
8.1 The material as represented by the test specimen, except as specified in 5.2 and 8.2, shall conform to the requirements as to the tensile properties prescribed in Table 2.
8.2 Shapes less than 1 in.² [645 mm²] in cross section and bars, other than flats, less than ½ in. [12.5 mm] in thickness or diameter need not be subjected to tension tests by the manufacturer, provided that the chemical composition used is appropriate for obtaining the tensile properties in Table 2.
| Property | Requirement |
|---|---|
| Plates, ShapesB, and Bars: | |
| Tensile strength, ksi [MPa] | 58-80 [400-550] |
| Yield point, min, ksi [MPa]C | 36 [250] |
| Plates and BarsD,E: | |
| Elongation in 8 in. [200 mm], min, % | 20 |
| Elongation in 2 in. [50 mm], min, % | 23 |
| Shapes: | |
| Elongation in 8 in. [200 mm], min, % | 20 |
| Elongation in 2 in. [50 mm], min, % | 21 |
See the Orientation subsection in the Tension Tests section of Specification A6/A6M.
B For wide flange shapes with flange thickness over 3 in. [75 mm], the 80 ksi [550 MPa] maximum tensile strength does not apply and a minimum elongation in 2 in. [50 mm] of 19% applies.
C Yield point 32 ksi [220 MPa] for plates over 8 in. [200 mm] in thickness.
D Elongation not required to be determined for floor plate.
E For plates wider than 24 in. [600 mm], the elongation requirement is reduced two percentage points. See the Elongation Requirement Adjustments subsection under the Tension Tests section of Specification A6/A6M.
9. Keywords
9.1 bars; bolted construction; bridges; buildings; carbon; plates; riveted construction; shapes; steel; structural steel; welded construction
SUPPLEMENTARY REQUIREMENTS
These requirements shall not apply unless specified in the order.
Standardized supplementary requirements for use at the option of the purchaser are listed in Specification A6/A6M. Those that are considered suitable for use with this specification are listed by title:
- S5. Charpy V-Notch Impact Test
- S30. Charpy V-Notch Impact Test for Structural Shapes: Alternate Core Location
- S32. Single Heat Bundles
- S32.1 Bundles containing shapes or bars shall be from a single heat of steel.
